From f84dbb912f344270f31d5cce974f12908a47798d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 10 Jul 2008 14:48:54 -0700 Subject: genirq: enable polling for disabled screaming irqs When we disable a screaming irq we never see it again. If the irq line is shared or if the driver half works this is a real pain. So periodically poll the handlers for screaming interrupts. I use a timer instead of the classic irq poll technique of working off the timer interrupt because when we use the local apic timers note_interrupt is never called (bug?). Further on a system with dynamic ticks the timer interrupt might not even fire unless there is a timer telling it it needs to. I forced this case on my test system with an e1000 nic and my ssh session remained responsive despite the interrupt handler only being called every 10th of a second. Signed-off-by: Eric W. Biederman Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 146 +++++++++++++++++++++++++++++++------------------- 1 file changed, 91 insertions(+), 55 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index c66d3f1..19fe9d6 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -12,83 +12,117 @@ #include #include #include +#include static int irqfixup __read_mostly; +#define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) +static void poll_spurious_irqs(unsigned long dummy); +static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); + /* * Recovery handler for misrouted interrupts. */ -static int misrouted_irq(int irq) +static int try_one_irq(int irq, struct irq_desc *desc) { - int i; + struct irqaction *action; int ok = 0; int work = 0; /* Did we do work for a real IRQ */ - for (i = 1; i < NR_IRQS; i++) { - struct irq_desc *desc = irq_desc + i; - struct irqaction *action; - - if (i == irq) /* Already tried */ - continue; - - spin_lock(&desc->lock); - /* Already running on another processor */ - if (desc->status & IRQ_INPROGRESS) { - /* - * Already running: If it is shared get the other - * CPU to go looking for our mystery interrupt too - */ - if (desc->action && (desc->action->flags & IRQF_SHARED)) - desc->status |= IRQ_PENDING; - spin_unlock(&desc->lock); - continue; - } - /* Honour the normal IRQ locking */ - desc->status |= IRQ_INPROGRESS; - action = desc->action; + spin_lock(&desc->lock); + /* Already running on another processor */ + if (desc->status & IRQ_INPROGRESS) { + /* + * Already running: If it is shared get the other + * CPU to go looking for our mystery interrupt too + */ + if (desc->action && (desc->action->flags & IRQF_SHARED)) + desc->status |= IRQ_PENDING; spin_unlock(&desc->lock); + return ok; + } + /* Honour the normal IRQ locking */ + desc->status |= IRQ_INPROGRESS; + action = desc->action; + spin_unlock(&desc->lock); - while (action) { - /* Only shared IRQ handlers are safe to call */ - if (action->flags & IRQF_SHARED) { - if (action->handler(i, action->dev_id) == - IRQ_HANDLED) - ok = 1; - } - action = action->next; + while (action) { + /* Only shared IRQ handlers are safe to call */ + if (action->flags & IRQF_SHARED) { + if (action->handler(irq, action->dev_id) == + IRQ_HANDLED) + ok = 1; } - local_irq_disable(); - /* Now clean up the flags */ - spin_lock(&desc->lock); - action = desc->action; + action = action->next; + } + local_irq_disable(); + /* Now clean up the flags */ + spin_lock(&desc->lock); + action = desc->action; + /* + * While we were looking for a fixup someone queued a real + * IRQ clashing with our walk: + */ + while ((desc->status & IRQ_PENDING) && action) { /* - * While we were looking for a fixup someone queued a real - * IRQ clashing with our walk: - */ - while ((desc->status & IRQ_PENDING) && action) { - /* - * Perform real IRQ processing for the IRQ we deferred - */ - work = 1; - spin_unlock(&desc->lock); - handle_IRQ_event(i, action); - spin_lock(&desc->lock); - desc->status &= ~IRQ_PENDING; - } - desc->status &= ~IRQ_INPROGRESS; - /* - * If we did actual work for the real IRQ line we must let the - * IRQ controller clean up too + * Perform real IRQ processing for the IRQ we deferred */ - if (work && desc->chip && desc->chip->end) - desc->chip->end(i); + work = 1; spin_unlock(&desc->lock); + handle_IRQ_event(irq, action); + spin_lock(&desc->lock); + desc->status &= ~IRQ_PENDING; + } + desc->status &= ~IRQ_INPROGRESS; + /* + * If we did actual work for the real IRQ line we must let the + * IRQ controller clean up too + */ + if (work && desc->chip && desc->chip->end) + desc->chip->end(irq); + spin_unlock(&desc->lock); + + return ok; +} + +static int misrouted_irq(int irq) +{ + int i; + int ok = 0; + + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + + if (i == irq) /* Already tried */ + continue; + + if (try_one_irq(i, desc)) + ok = 1; } /* So the caller can adjust the irq error counts */ return ok; } +static void poll_spurious_irqs(unsigned long dummy) +{ + int i; + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + unsigned int status; + + /* Racy but it doesn't matter */ + status = desc->status; + barrier(); + if (!(status & IRQ_SPURIOUS_DISABLED)) + continue; + + try_one_irq(i, desc); + } + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); +} + /* * If 99,900 of the previous 100,000 interrupts have not been handled * then assume that the IRQ is stuck in some manner. Drop a diagnostic @@ -212,6 +246,8 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; desc->depth++; desc->chip->disable(irq); + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } desc->irqs_unhandled = 0; } -- cgit v1.1 From 8d00a6c8f6b08e7167bc03bf955cdc7e47c5132e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 22 Jul 2008 08:39:57 +0200 Subject: genirq: remove last NO_IDLE_HZ leftovers Signed-off-by: Thomas Gleixner --- kernel/irq/handle.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 5fa6198..f4c8a03 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -131,8 +131,6 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) irqreturn_t ret, retval = IRQ_NONE; unsigned int status = 0; - handle_dynamic_tick(action); - if (!(action->flags & IRQF_DISABLED)) local_irq_enable_in_hardirq(); -- cgit v1.1 From 1aa5dfb751d275ae7117d3b73ac423b4a46f2a73 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 20 Aug 2008 16:37:28 -0700 Subject: clocksource: keep track of original clocksource frequency The clocksource frequency is represented by clocksource->mult/2^(clocksource->shift). Currently, when NTP makes adjustments to the clock frequency, they are made directly to the mult value. This has the drawback that once changed, we cannot know what the orignal mult value was, or how much adjustment has been applied. This property causes problems in calculating proper ntp intervals when switching back and forth between clocksources. This patch separates the current mult value into a mult and mult_orig pair. The mult_orig value stays constant, while the ntp clocksource adjustments are done only to the mult value. This allows for correct ntp interval calculation and additionally lays the groundwork for a new notion of time, what I'm calling the monotonic-raw time, which is introduced in a following patch. Signed-off-by: John Stultz Signed-off-by: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/time/clocksource.c | 3 +++ kernel/time/jiffies.c | 1 + 2 files changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 093d4ac..9ed2eec 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -325,6 +325,9 @@ int clocksource_register(struct clocksource *c) unsigned long flags; int ret; + /* save mult_orig on registration */ + c->mult_orig = c->mult; + spin_lock_irqsave(&clocksource_lock, flags); ret = clocksource_enqueue(c); if (!ret) diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index 4c256fd..1ca9955 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -61,6 +61,7 @@ struct clocksource clocksource_jiffies = { .read = jiffies_read, .mask = 0xffffffff, /*32bits*/ .mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */ + .mult_orig = NSEC_PER_JIFFY << JIFFIES_SHIFT, .shift = JIFFIES_SHIFT, }; -- cgit v1.1 From 9a055117d3d9cb562f83f8d4cd88772761f4cab0 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Wed, 20 Aug 2008 16:37:28 -0700 Subject: clocksource: introduce clocksource_forward_now() To keep the raw monotonic patch simple first introduce clocksource_forward_now(), which takes care of the offset since the last update_wall_time() call and adds it to the clock, so there is no need anymore to deal with it explicitly at various places, which need to make significant changes to the clock. This is also gets rid of the timekeeping_suspend_nsecs, instead of waiting until resume, the value is accumulated during suspend. In the end there is only a single user of __get_nsec_offset() left, so I integrated it back to getnstimeofday(). Signed-off-by: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/time/timekeeping.c | 71 ++++++++++++++++++++++------------------------- 1 file changed, 33 insertions(+), 38 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e91c29f..83d3555 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -58,27 +58,23 @@ struct clocksource *clock; #ifdef CONFIG_GENERIC_TIME /** - * __get_nsec_offset - Returns nanoseconds since last call to periodic_hook + * clocksource_forward_now - update clock to the current time * - * private function, must hold xtime_lock lock when being - * called. Returns the number of nanoseconds since the - * last call to update_wall_time() (adjusted by NTP scaling) + * Forward the current clock to update its state since the last call to + * update_wall_time(). This is useful before significant clock changes, + * as it avoids having to deal with this time offset explicitly. */ -static inline s64 __get_nsec_offset(void) +static void clocksource_forward_now(void) { cycle_t cycle_now, cycle_delta; - s64 ns_offset; + s64 nsec; - /* read clocksource: */ cycle_now = clocksource_read(clock); - - /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + clock->cycle_last = cycle_now; - /* convert to nanoseconds: */ - ns_offset = cyc2ns(clock, cycle_delta); - - return ns_offset; + nsec = cyc2ns(clock, cycle_delta); + timespec_add_ns(&xtime, nsec); } /** @@ -89,6 +85,7 @@ static inline s64 __get_nsec_offset(void) */ void getnstimeofday(struct timespec *ts) { + cycle_t cycle_now, cycle_delta; unsigned long seq; s64 nsecs; @@ -96,7 +93,15 @@ void getnstimeofday(struct timespec *ts) seq = read_seqbegin(&xtime_lock); *ts = xtime; - nsecs = __get_nsec_offset(); + + /* read clocksource: */ + cycle_now = clocksource_read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* convert to nanoseconds: */ + nsecs = cyc2ns(clock, cycle_delta); } while (read_seqretry(&xtime_lock, seq)); @@ -129,22 +134,22 @@ EXPORT_SYMBOL(do_gettimeofday); */ int do_settimeofday(struct timespec *tv) { + struct timespec ts_delta; unsigned long flags; - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) return -EINVAL; write_seqlock_irqsave(&xtime_lock, flags); - nsec -= __get_nsec_offset(); + clocksource_forward_now(); + + ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; + ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; + wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); + xtime = *tv; - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); update_xtime_cache(0); clock->error = 0; @@ -170,22 +175,17 @@ EXPORT_SYMBOL(do_settimeofday); static void change_clocksource(void) { struct clocksource *new; - cycle_t now; - u64 nsec; new = clocksource_get_next(); if (clock == new) return; - new->cycle_last = 0; - now = clocksource_read(new); - nsec = __get_nsec_offset(); - timespec_add_ns(&xtime, nsec); + clocksource_forward_now(); clock = new; - clock->cycle_last = now; - + clock->cycle_last = 0; + clock->cycle_last = clocksource_read(new); clock->error = 0; clock->xtime_nsec = 0; clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); @@ -200,8 +200,8 @@ static void change_clocksource(void) */ } #else +static inline void clocksource_forward_now(void) { } static inline void change_clocksource(void) { } -static inline s64 __get_nsec_offset(void) { return 0; } #endif /** @@ -265,8 +265,6 @@ void __init timekeeping_init(void) static int timekeeping_suspended; /* time in seconds when suspend began */ static unsigned long timekeeping_suspend_time; -/* xtime offset when we went into suspend */ -static s64 timekeeping_suspend_nsecs; /** * timekeeping_resume - Resumes the generic timekeeping subsystem. @@ -292,8 +290,6 @@ static int timekeeping_resume(struct sys_device *dev) wall_to_monotonic.tv_sec -= sleep_length; total_sleep_time += sleep_length; } - /* Make sure that we have the correct xtime reference */ - timespec_add_ns(&xtime, timekeeping_suspend_nsecs); update_xtime_cache(0); /* re-base the last cycle value */ clock->cycle_last = 0; @@ -319,8 +315,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) timekeeping_suspend_time = read_persistent_clock(); write_seqlock_irqsave(&xtime_lock, flags); - /* Get the current xtime offset */ - timekeeping_suspend_nsecs = __get_nsec_offset(); + clocksource_forward_now(); timekeeping_suspended = 1; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -461,10 +456,10 @@ void update_wall_time(void) */ while (offset >= clock->cycle_interval) { /* accumulate one interval */ - clock->xtime_nsec += clock->xtime_interval; - clock->cycle_last += clock->cycle_interval; offset -= clock->cycle_interval; + clock->cycle_last += clock->cycle_interval; + clock->xtime_nsec += clock->xtime_interval; if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) { clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift; xtime.tv_sec++; -- cgit v1.1 From 2d42244ae71d6c7b0884b5664cf2eda30fb2ae68 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 20 Aug 2008 16:37:30 -0700 Subject: clocksource: introduce CLOCK_MONOTONIC_RAW In talking with Josip Loncaric, and his work on clock synchronization (see btime.sf.net), he mentioned that for really close synchronization, it is useful to have access to "hardware time", that is a notion of time that is not in any way adjusted by the clock slewing done to keep close time sync. Part of the issue is if we are using the kernel's ntp adjusted representation of time in order to measure how we should correct time, we can run into what Paul McKenney aptly described as "Painting a road using the lines we're painting as the guide". I had been thinking of a similar problem, and was trying to come up with a way to give users access to a purely hardware based time representation that avoided users having to know the underlying frequency and mask values needed to deal with the wide variety of possible underlying hardware counters. My solution is to introduce CLOCK_MONOTONIC_RAW. This exposes a nanosecond based time value, that increments starting at bootup and has no frequency adjustments made to it what so ever. The time is accessed from userspace via the posix_clock_gettime() syscall, passing CLOCK_MONOTONIC_RAW as the clock_id. Signed-off-by: John Stultz Signed-off-by: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/posix-timers.c | 15 +++++++++++++++ kernel/time/timekeeping.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e36d579..d3c66b5 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -223,6 +223,15 @@ static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) } /* + * Get monotonic time for posix timers + */ +static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp) +{ + getrawmonotonic(tp); + return 0; +} + +/* * Initialize everything, well, just everything in Posix clocks/timers ;) */ static __init int init_posix_timers(void) @@ -235,9 +244,15 @@ static __init int init_posix_timers(void) .clock_get = posix_ktime_get_ts, .clock_set = do_posix_clock_nosettime, }; + struct k_clock clock_monotonic_raw = { + .clock_getres = hrtimer_get_res, + .clock_get = posix_get_monotonic_raw, + .clock_set = do_posix_clock_nosettime, + }; register_posix_clock(CLOCK_REALTIME, &clock_realtime); register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); + register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw); posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 83d3555..5099c95 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -75,6 +75,9 @@ static void clocksource_forward_now(void) nsec = cyc2ns(clock, cycle_delta); timespec_add_ns(&xtime, nsec); + + nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; + clock->raw_time.tv_nsec += nsec; } /** @@ -183,6 +186,8 @@ static void change_clocksource(void) clocksource_forward_now(); + new->raw_time = clock->raw_time; + clock = new; clock->cycle_last = 0; clock->cycle_last = clocksource_read(new); @@ -205,6 +210,39 @@ static inline void change_clocksource(void) { } #endif /** + * getrawmonotonic - Returns the raw monotonic time in a timespec + * @ts: pointer to the timespec to be set + * + * Returns the raw monotonic time (completely un-modified by ntp) + */ +void getrawmonotonic(struct timespec *ts) +{ + unsigned long seq; + s64 nsecs; + cycle_t cycle_now, cycle_delta; + + do { + seq = read_seqbegin(&xtime_lock); + + /* read clocksource: */ + cycle_now = clocksource_read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* convert to nanoseconds: */ + nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; + + *ts = clock->raw_time; + + } while (read_seqretry(&xtime_lock, seq)); + + timespec_add_ns(ts, nsecs); +} +EXPORT_SYMBOL(getrawmonotonic); + + +/** * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres */ int timekeeping_valid_for_hres(void) @@ -466,6 +504,12 @@ void update_wall_time(void) second_overflow(); } + clock->raw_time.tv_nsec += clock->raw_interval; + if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) { + clock->raw_time.tv_nsec -= NSEC_PER_SEC; + clock->raw_time.tv_sec++; + } + /* accumulate error between NTP and clock interval */ clock->error += tick_length; clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift); -- cgit v1.1 From d82f0b0f6f1a0a25afc288fb7135b1601fe6df18 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 20 Aug 2008 16:46:04 -0700 Subject: migrate_timers: add comment, use spinlock_irq() Add the comment to explain why the double lock in migrate_timers() can't deadlock. Change the code to use spinlock_irq() instead of local_irq_disable() + spin_lock(). Signed-off-by: Oleg Nesterov Acked-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/hrtimer.c | 11 ++++++----- kernel/timer.c | 11 ++++++----- 2 files changed, 12 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b8e4dce..03ea137 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1620,9 +1620,11 @@ static void migrate_hrtimers(int cpu) new_base = &get_cpu_var(hrtimer_bases); tick_cancel_sched_timer(cpu); - - local_irq_disable(); - spin_lock(&new_base->lock); + /* + * The caller is globally serialized and nobody else + * takes two locks at once, deadlock is not possible. + */ + spin_lock_irq(&new_base->lock); spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { @@ -1631,8 +1633,7 @@ static void migrate_hrtimers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_enable(); + spin_unlock_irq(&new_base->lock); put_cpu_var(hrtimer_bases); } #endif /* CONFIG_HOTPLUG_CPU */ diff --git a/kernel/timer.c b/kernel/timer.c index 03bc7f1..e8019cc 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1435,9 +1435,11 @@ static void __cpuinit migrate_timers(int cpu) BUG_ON(cpu_online(cpu)); old_base = per_cpu(tvec_bases, cpu); new_base = get_cpu_var(tvec_bases); - - local_irq_disable(); - spin_lock(&new_base->lock); + /* + * The caller is globally serialized and nobody else + * takes two locks at once, deadlock is not possible. + */ + spin_lock_irq(&new_base->lock); spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); BUG_ON(old_base->running_timer); @@ -1452,8 +1454,7 @@ static void __cpuinit migrate_timers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_enable(); + spin_unlock_irq(&new_base->lock); put_cpu_var(tvec_bases); } #endif /* CONFIG_HOTPLUG_CPU */ -- cgit v1.1 From 916c7a855174e3b53d182b97a26b2e27a29726a1 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Wed, 20 Aug 2008 16:46:08 -0700 Subject: ntp: fix ADJ_OFFSET_SS_READ bug and do_adjtimex() cleanup Thanks to the review by Michael Kerrisk a bug in the recent ADJ_OFFSET_SS_READ option was discovered, where the ntp time_offset was inadvertently set by it. This fixes this by making the adjtime code more separate from the ntp_adjtime code (both of which really want to be separate syscalls). Signed-off-by: Roman Zippel Signed-off-by: Andrew Morton Acked-by: John Stultz Signed-off-by: Ingo Molnar --- kernel/time/ntp.c | 76 +++++++++++++++++++++++++++++-------------------------- 1 file changed, 40 insertions(+), 36 deletions(-) (limited to 'kernel') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 5125ddd..c6921aa1 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -277,38 +277,50 @@ static inline void notify_cmos_timer(void) { } int do_adjtimex(struct timex *txc) { struct timespec ts; - long save_adjust, sec; int result; - /* In order to modify anything, you gotta be super-user! */ - if (txc->modes && !capable(CAP_SYS_TIME)) - return -EPERM; - - /* Now we validate the data before disabling interrupts */ - - if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) { + /* Validate the data before disabling interrupts */ + if (txc->modes & ADJ_ADJTIME) { /* singleshot must not be used with any other mode bits */ - if (txc->modes & ~ADJ_OFFSET_SS_READ) + if (!(txc->modes & ADJ_OFFSET_SINGLESHOT)) return -EINVAL; + if (!(txc->modes & ADJ_OFFSET_READONLY) && + !capable(CAP_SYS_TIME)) + return -EPERM; + } else { + /* In order to modify anything, you gotta be super-user! */ + if (txc->modes && !capable(CAP_SYS_TIME)) + return -EPERM; + + /* if the quartz is off by more than 10% something is VERY wrong! */ + if (txc->modes & ADJ_TICK && + (txc->tick < 900000/USER_HZ || + txc->tick > 1100000/USER_HZ)) + return -EINVAL; + + if (txc->modes & ADJ_STATUS && time_state != TIME_OK) + hrtimer_cancel(&leap_timer); } - /* if the quartz is off by more than 10% something is VERY wrong ! */ - if (txc->modes & ADJ_TICK) - if (txc->tick < 900000/USER_HZ || - txc->tick > 1100000/USER_HZ) - return -EINVAL; - - if (time_state != TIME_OK && txc->modes & ADJ_STATUS) - hrtimer_cancel(&leap_timer); getnstimeofday(&ts); write_seqlock_irq(&xtime_lock); - /* Save for later - semantics of adjtime is to return old value */ - save_adjust = time_adjust; - /* If there are input parameters, then process them */ + if (txc->modes & ADJ_ADJTIME) { + long save_adjust = time_adjust; + + if (!(txc->modes & ADJ_OFFSET_READONLY)) { + /* adjtime() is independent from ntp_adjtime() */ + time_adjust = txc->offset; + ntp_update_frequency(); + } + txc->offset = save_adjust; + goto adj_done; + } if (txc->modes) { + long sec; + if (txc->modes & ADJ_STATUS) { if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) { @@ -375,13 +387,8 @@ int do_adjtimex(struct timex *txc) if (txc->modes & ADJ_TAI && txc->constant > 0) time_tai = txc->constant; - if (txc->modes & ADJ_OFFSET) { - if (txc->modes == ADJ_OFFSET_SINGLESHOT) - /* adjtime() is independent from ntp_adjtime() */ - time_adjust = txc->offset; - else - ntp_update_offset(txc->offset); - } + if (txc->modes & ADJ_OFFSET) + ntp_update_offset(txc->offset); if (txc->modes & ADJ_TICK) tick_usec = txc->tick; @@ -389,19 +396,16 @@ int do_adjtimex(struct timex *txc) ntp_update_frequency(); } + txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ, + NTP_SCALE_SHIFT); + if (!(time_status & STA_NANO)) + txc->offset /= NSEC_PER_USEC; + +adj_done: result = time_state; /* mostly `TIME_OK' */ if (time_status & (STA_UNSYNC|STA_CLOCKERR)) result = TIME_ERROR; - if ((txc->modes == ADJ_OFFSET_SINGLESHOT) || - (txc->modes == ADJ_OFFSET_SS_READ)) - txc->offset = save_adjust; - else { - txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ, - NTP_SCALE_SHIFT); - if (!(time_status & STA_NANO)) - txc->offset /= NSEC_PER_USEC; - } txc->freq = shift_right((s32)(time_freq >> PPM_SCALE_INV_SHIFT) * (s64)PPM_SCALE_INV, NTP_SCALE_SHIFT); -- cgit v1.1 From 377bf1e4ac2d894791733270604594c7c851ef83 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Thu, 21 Aug 2008 22:58:28 +0400 Subject: genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov Cc: David Woodhouse Signed-off-by: Ingo Molnar --- kernel/irq/manage.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 77a51be..ae1b684 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -596,26 +596,29 @@ int request_irq(unsigned int irq, irq_handler_t handler, action->next = NULL; action->dev_id = dev_id; + retval = setup_irq(irq, action); + if (retval) + kfree(action); + #ifdef CONFIG_DEBUG_SHIRQ if (irqflags & IRQF_SHARED) { /* * It's a shared IRQ -- the driver ought to be prepared for it * to happen immediately, so let's make sure.... - * We do this before actually registering it, to make sure that - * a 'real' IRQ doesn't run in parallel with our fake + * We disable the irq to make sure that a 'real' IRQ doesn't + * run in parallel with our fake. */ unsigned long flags; + disable_irq(irq); local_irq_save(flags); + handler(irq, dev_id); + local_irq_restore(flags); + enable_irq(irq); } #endif - - retval = setup_irq(irq, action); - if (retval) - kfree(action); - return retval; } EXPORT_SYMBOL(request_irq); -- cgit v1.1 From 7bb67439bf6bd3782f07f1d7be1e63406453d5de Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 31 Aug 2008 08:05:58 -0700 Subject: select: Introduce a hrtimeout function This patch adds a schedule_hrtimeout() function, to be used by select() and poll() in a later patch. This function works similar to schedule_timeout() in most ways, but takes a timespec rather than jiffies. With a lot of contributions/fixes from Thomas Signed-off-by: Arjan van de Ven Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b8e4dce..782137d 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1678,3 +1678,68 @@ void __init hrtimers_init(void) #endif } +/** + * schedule_hrtimeout - sleep until timeout + * @expires: timeout value (ktime_t) + * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL + * + * Make the current task sleep until the given expiry time has + * elapsed. The routine will return immediately unless + * the current task state has been set (see set_current_state()). + * + * You can set the task state as follows - + * + * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to + * pass before the routine returns. + * + * %TASK_INTERRUPTIBLE - the routine may return early if a signal is + * delivered to the current task. + * + * The current task state is guaranteed to be TASK_RUNNING when this + * routine returns. + * + * Returns 0 when the timer has expired otherwise -EINTR + */ +int __sched schedule_hrtimeout(ktime_t *expires, + const enum hrtimer_mode mode) +{ + struct hrtimer_sleeper t; + + /* + * Optimize when a zero timeout value is given. It does not + * matter whether this is an absolute or a relative time. + */ + if (expires && !expires->tv64) { + __set_current_state(TASK_RUNNING); + return 0; + } + + /* + * A NULL parameter means "inifinte" + */ + if (!expires) { + schedule(); + __set_current_state(TASK_RUNNING); + return -EINTR; + } + + hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode); + t.timer.expires = *expires; + + hrtimer_init_sleeper(&t, current); + + hrtimer_start(&t.timer, t.timer.expires, mode); + if (!hrtimer_active(&t.timer)) + t.task = NULL; + + if (likely(t.task)) + schedule(); + + hrtimer_cancel(&t.timer); + destroy_hrtimer_on_stack(&t.timer); + + __set_current_state(TASK_RUNNING); + + return !t.task ? 0 : -EINTR; +} +EXPORT_SYMBOL_GPL(schedule_hrtimeout); -- cgit v1.1 From df0cc0539b4127bd02f64de2c335b4af1fdb3845 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 31 Aug 2008 08:09:53 -0700 Subject: select: add a timespec_add_safe() function For the select() rework, it's important to be able to add timespec structures in an overflow-safe manner. This patch adds a timespec_add_safe() function for this which is similar in operation to ktime_add_safe(), but works on a struct timespec. Signed-off-by: Thomas Gleixner Signed-off-by: Arjan van de Ven --- kernel/time.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'kernel') diff --git a/kernel/time.c b/kernel/time.c index 6a08660..d63a433 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -669,3 +669,21 @@ EXPORT_SYMBOL(get_jiffies_64); #endif EXPORT_SYMBOL(jiffies); + +/* + * Add two timespec values and do a safety check for overflow. + * It's assumed that both values are valid (>= 0) + */ +struct timespec timespec_add_safe(const struct timespec lhs, + const struct timespec rhs) +{ + struct timespec res; + + set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + + if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec) + res.tv_sec = TIME_T_MAX; + + return res; +} -- cgit v1.1 From cc584b213f252bf698849cf4be2377cd3ec7501a Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 1 Sep 2008 15:02:30 -0700 Subject: hrtimer: convert kernel/* to the new hrtimer apis In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch converts kernel/* to these accessors. Signed-off-by: Arjan van de Ven --- kernel/futex.c | 7 +++---- kernel/hrtimer.c | 44 +++++++++++++++++++++++--------------------- kernel/posix-timers.c | 10 ++++------ kernel/rtmutex.c | 3 +-- kernel/sched.c | 7 +++---- kernel/time/ntp.c | 3 +-- kernel/time/tick-sched.c | 21 ++++++++++----------- kernel/time/timer_list.c | 4 ++-- 8 files changed, 47 insertions(+), 52 deletions(-) (limited to 'kernel') diff --git a/kernel/futex.c b/kernel/futex.c index 7d1136e..4cd5b43 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1299,10 +1299,9 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); hrtimer_init_sleeper(&t, current); - t.timer.expires = *abs_time; + hrtimer_set_expires(&t.timer, *abs_time); - hrtimer_start(&t.timer, t.timer.expires, - HRTIMER_MODE_ABS); + hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS); if (!hrtimer_active(&t.timer)) t.task = NULL; @@ -1404,7 +1403,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); hrtimer_init_sleeper(to, current); - to->timer.expires = *time; + hrtimer_set_expires(&to->timer, *time); } q.pi_state = NULL; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 782137d..ae307fe 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -517,7 +517,7 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base) if (!base->first) continue; timer = rb_entry(base->first, struct hrtimer, node); - expires = ktime_sub(timer->expires, base->offset); + expires = ktime_sub(hrtimer_get_expires(timer), base->offset); if (expires.tv64 < cpu_base->expires_next.tv64) cpu_base->expires_next = expires; } @@ -539,10 +539,10 @@ static int hrtimer_reprogram(struct hrtimer *timer, struct hrtimer_clock_base *base) { ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next; - ktime_t expires = ktime_sub(timer->expires, base->offset); + ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); int res; - WARN_ON_ONCE(timer->expires.tv64 < 0); + WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); /* * When the callback is running, we do not reprogram the clock event @@ -794,7 +794,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) u64 orun = 1; ktime_t delta; - delta = ktime_sub(now, timer->expires); + delta = ktime_sub(now, hrtimer_get_expires(timer)); if (delta.tv64 < 0) return 0; @@ -806,8 +806,8 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) s64 incr = ktime_to_ns(interval); orun = ktime_divns(delta, incr); - timer->expires = ktime_add_ns(timer->expires, incr * orun); - if (timer->expires.tv64 > now.tv64) + hrtimer_add_expires_ns(timer, incr * orun); + if (hrtimer_get_expires_tv64(timer) > now.tv64) return orun; /* * This (and the ktime_add() below) is the @@ -815,7 +815,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) */ orun++; } - timer->expires = ktime_add_safe(timer->expires, interval); + hrtimer_add_expires(timer, interval); return orun; } @@ -847,7 +847,8 @@ static void enqueue_hrtimer(struct hrtimer *timer, * We dont care about collisions. Nodes with * the same expiry time stay together. */ - if (timer->expires.tv64 < entry->expires.tv64) { + if (hrtimer_get_expires_tv64(timer) < + hrtimer_get_expires_tv64(entry)) { link = &(*link)->rb_left; } else { link = &(*link)->rb_right; @@ -982,7 +983,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) #endif } - timer->expires = tim; + hrtimer_set_expires(timer, tim); timer_stats_hrtimer_set_start_info(timer); @@ -1076,7 +1077,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) ktime_t rem; base = lock_hrtimer_base(timer, &flags); - rem = ktime_sub(timer->expires, base->get_time()); + rem = hrtimer_expires_remaining(timer); unlock_hrtimer_base(timer, &flags); return rem; @@ -1108,7 +1109,7 @@ ktime_t hrtimer_get_next_event(void) continue; timer = rb_entry(base->first, struct hrtimer, node); - delta.tv64 = timer->expires.tv64; + delta.tv64 = hrtimer_get_expires_tv64(timer); delta = ktime_sub(delta, base->get_time()); if (delta.tv64 < mindelta.tv64) mindelta.tv64 = delta.tv64; @@ -1308,10 +1309,10 @@ void hrtimer_interrupt(struct clock_event_device *dev) timer = rb_entry(node, struct hrtimer, node); - if (basenow.tv64 < timer->expires.tv64) { + if (basenow.tv64 < hrtimer_get_expires_tv64(timer)) { ktime_t expires; - expires = ktime_sub(timer->expires, + expires = ktime_sub(hrtimer_get_expires(timer), base->offset); if (expires.tv64 < expires_next.tv64) expires_next = expires; @@ -1414,7 +1415,8 @@ void hrtimer_run_queues(void) struct hrtimer *timer; timer = rb_entry(node, struct hrtimer, node); - if (base->softirq_time.tv64 <= timer->expires.tv64) + if (base->softirq_time.tv64 <= + hrtimer_get_expires_tv64(timer)) break; if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { @@ -1462,7 +1464,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod do { set_current_state(TASK_INTERRUPTIBLE); - hrtimer_start(&t->timer, t->timer.expires, mode); + hrtimer_start_expires(&t->timer, mode); if (!hrtimer_active(&t->timer)) t->task = NULL; @@ -1484,7 +1486,7 @@ static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) struct timespec rmt; ktime_t rem; - rem = ktime_sub(timer->expires, timer->base->get_time()); + rem = hrtimer_expires_remaining(timer); if (rem.tv64 <= 0) return 0; rmt = ktime_to_timespec(rem); @@ -1503,7 +1505,7 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) hrtimer_init_on_stack(&t.timer, restart->nanosleep.index, HRTIMER_MODE_ABS); - t.timer.expires.tv64 = restart->nanosleep.expires; + hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); if (do_nanosleep(&t, HRTIMER_MODE_ABS)) goto out; @@ -1530,7 +1532,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, int ret = 0; hrtimer_init_on_stack(&t.timer, clockid, mode); - t.timer.expires = timespec_to_ktime(*rqtp); + hrtimer_set_expires(&t.timer, timespec_to_ktime(*rqtp)); if (do_nanosleep(&t, mode)) goto out; @@ -1550,7 +1552,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, restart->fn = hrtimer_nanosleep_restart; restart->nanosleep.index = t.timer.base->index; restart->nanosleep.rmtp = rmtp; - restart->nanosleep.expires = t.timer.expires.tv64; + restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); ret = -ERESTART_RESTARTBLOCK; out: @@ -1724,11 +1726,11 @@ int __sched schedule_hrtimeout(ktime_t *expires, } hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode); - t.timer.expires = *expires; + hrtimer_set_expires(&t.timer, *expires); hrtimer_init_sleeper(&t, current); - hrtimer_start(&t.timer, t.timer.expires, mode); + hrtimer_start_expires(&t.timer, mode); if (!hrtimer_active(&t.timer)) t.task = NULL; diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e36d579..f85efcd 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -668,7 +668,7 @@ common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv); - remaining = ktime_sub(timer->expires, now); + remaining = ktime_sub(hrtimer_get_expires(timer), now); /* Return 0 only, when the timer is expired and not pending */ if (remaining.tv64 <= 0) { /* @@ -762,7 +762,7 @@ common_timer_set(struct k_itimer *timr, int flags, hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); timr->it.real.timer.function = posix_timer_fn; - timer->expires = timespec_to_ktime(new_setting->it_value); + hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value)); /* Convert interval */ timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); @@ -771,14 +771,12 @@ common_timer_set(struct k_itimer *timr, int flags, if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { /* Setup correct expiry time for relative timers */ if (mode == HRTIMER_MODE_REL) { - timer->expires = - ktime_add_safe(timer->expires, - timer->base->get_time()); + hrtimer_add_expires(timer, timer->base->get_time()); } return 0; } - hrtimer_start(timer, timer->expires, mode); + hrtimer_start_expires(timer, mode); return 0; } diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 6522ae5..69d9cb9 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -631,8 +631,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, /* Setup the timer, when timeout != NULL */ if (unlikely(timeout)) { - hrtimer_start(&timeout->timer, timeout->timer.expires, - HRTIMER_MODE_ABS); + hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); if (!hrtimer_active(&timeout->timer)) timeout->task = NULL; } diff --git a/kernel/sched.c b/kernel/sched.c index 1a5f73c..e46b5af 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -221,9 +221,8 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b) now = hrtimer_cb_get_time(&rt_b->rt_period_timer); hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); - hrtimer_start(&rt_b->rt_period_timer, - rt_b->rt_period_timer.expires, - HRTIMER_MODE_ABS); + hrtimer_start_expires(&rt_b->rt_period_timer, + HRTIMER_MODE_ABS); } spin_unlock(&rt_b->rt_runtime_lock); } @@ -1058,7 +1057,7 @@ static void hrtick_start(struct rq *rq, u64 delay) struct hrtimer *timer = &rq->hrtick_timer; ktime_t time = ktime_add_ns(timer->base->get_time(), delay); - timer->expires = time; + hrtimer_set_expires(timer, time); if (rq == this_rq()) { hrtimer_restart(timer); diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 5125ddd..4c8d854 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -142,8 +142,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) time_state = TIME_OOP; printk(KERN_NOTICE "Clock: " "inserting leap second 23:59:60 UTC\n"); - leap_timer.expires = ktime_add_ns(leap_timer.expires, - NSEC_PER_SEC); + hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC); res = HRTIMER_RESTART; break; case TIME_DEL: diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index a87b046..b33be61 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -288,7 +288,7 @@ void tick_nohz_stop_sched_tick(int inidle) goto out; } - ts->idle_tick = ts->sched_timer.expires; + ts->idle_tick = hrtimer_get_expires(&ts->sched_timer); ts->tick_stopped = 1; ts->idle_jiffies = last_jiffies; rcu_enter_nohz(); @@ -419,21 +419,21 @@ void tick_nohz_restart_sched_tick(void) ts->tick_stopped = 0; ts->idle_exittime = now; hrtimer_cancel(&ts->sched_timer); - ts->sched_timer.expires = ts->idle_tick; + hrtimer_set_expires(&ts->sched_timer, ts->idle_tick); while (1) { /* Forward the time to expire in the future */ hrtimer_forward(&ts->sched_timer, now, tick_period); if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { - hrtimer_start(&ts->sched_timer, - ts->sched_timer.expires, + hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS); /* Check, if the timer was already in the past */ if (hrtimer_active(&ts->sched_timer)) break; } else { - if (!tick_program_event(ts->sched_timer.expires, 0)) + if (!tick_program_event( + hrtimer_get_expires(&ts->sched_timer), 0)) break; } /* Update jiffies and reread time */ @@ -446,7 +446,7 @@ void tick_nohz_restart_sched_tick(void) static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now) { hrtimer_forward(&ts->sched_timer, now, tick_period); - return tick_program_event(ts->sched_timer.expires, 0); + return tick_program_event(hrtimer_get_expires(&ts->sched_timer), 0); } /* @@ -529,7 +529,7 @@ static void tick_nohz_switch_to_nohz(void) next = tick_init_jiffy_update(); for (;;) { - ts->sched_timer.expires = next; + hrtimer_set_expires(&ts->sched_timer, next); if (!tick_program_event(next, 0)) break; next = ktime_add(next, tick_period); @@ -625,16 +625,15 @@ void tick_setup_sched_timer(void) ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; /* Get the next period (per cpu) */ - ts->sched_timer.expires = tick_init_jiffy_update(); + hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update()); offset = ktime_to_ns(tick_period) >> 1; do_div(offset, num_possible_cpus()); offset *= smp_processor_id(); - ts->sched_timer.expires = ktime_add_ns(ts->sched_timer.expires, offset); + hrtimer_add_expires_ns(&ts->sched_timer, offset); for (;;) { hrtimer_forward(&ts->sched_timer, now, tick_period); - hrtimer_start(&ts->sched_timer, ts->sched_timer.expires, - HRTIMER_MODE_ABS); + hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS); /* Check, if the timer was already in the past */ if (hrtimer_active(&ts->sched_timer)) break; diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index a40e20f..5224a32 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -66,8 +66,8 @@ print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now) #endif SEQ_printf(m, "\n"); SEQ_printf(m, " # expires at %Lu nsecs [in %Ld nsecs]\n", - (unsigned long long)ktime_to_ns(timer->expires), - (long long)(ktime_to_ns(timer->expires) - now)); + (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), + (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); } static void -- cgit v1.1 From 654c8e0b1c623b156c5b92f28d914ab38c9c2c90 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 1 Sep 2008 15:47:08 -0700 Subject: hrtimer: turn hrtimers into range timers this patch turns hrtimers into range timers; they have 2 expire points 1) the soft expire point 2) the hard expire point the kernel will do it's regular best effort attempt to get the timer run at the hard expire point. However, if some other time fires after the soft expire point, the kernel now has the freedom to fire this timer at this point, and thus grouping the events and preventing a power-expensive wakeup in the future. Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 52 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index ae307fe..0148300 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1309,7 +1309,20 @@ void hrtimer_interrupt(struct clock_event_device *dev) timer = rb_entry(node, struct hrtimer, node); - if (basenow.tv64 < hrtimer_get_expires_tv64(timer)) { + /* + * The immediate goal for using the softexpires is + * minimizing wakeups, not running timers at the + * earliest interrupt after their soft expiration. + * This allows us to avoid using a Priority Search + * Tree, which can answer a stabbing querry for + * overlapping intervals and instead use the simple + * BST we already have. + * We don't add extra wakeups by delaying timers that + * are right-of a not yet expired timer, because that + * timer will have to trigger a wakeup anyway. + */ + + if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) { ktime_t expires; expires = ktime_sub(hrtimer_get_expires(timer), @@ -1681,14 +1694,20 @@ void __init hrtimers_init(void) } /** - * schedule_hrtimeout - sleep until timeout + * schedule_hrtimeout_range - sleep until timeout * @expires: timeout value (ktime_t) + * @delta: slack in expires timeout (ktime_t) * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL * * Make the current task sleep until the given expiry time has * elapsed. The routine will return immediately unless * the current task state has been set (see set_current_state()). * + * The @delta argument gives the kernel the freedom to schedule the + * actual wakeup to a time that is both power and performance friendly. + * The kernel give the normal best effort behavior for "@expires+@delta", + * but may decide to fire the timer earlier, but no earlier than @expires. + * * You can set the task state as follows - * * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to @@ -1702,7 +1721,7 @@ void __init hrtimers_init(void) * * Returns 0 when the timer has expired otherwise -EINTR */ -int __sched schedule_hrtimeout(ktime_t *expires, +int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, const enum hrtimer_mode mode) { struct hrtimer_sleeper t; @@ -1726,7 +1745,7 @@ int __sched schedule_hrtimeout(ktime_t *expires, } hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode); - hrtimer_set_expires(&t.timer, *expires); + hrtimer_set_expires_range_ns(&t.timer, *expires, delta); hrtimer_init_sleeper(&t, current); @@ -1744,4 +1763,33 @@ int __sched schedule_hrtimeout(ktime_t *expires, return !t.task ? 0 : -EINTR; } +EXPORT_SYMBOL_GPL(schedule_hrtimeout_range); + +/** + * schedule_hrtimeout - sleep until timeout + * @expires: timeout value (ktime_t) + * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL + * + * Make the current task sleep until the given expiry time has + * elapsed. The routine will return immediately unless + * the current task state has been set (see set_current_state()). + * + * You can set the task state as follows - + * + * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to + * pass before the routine returns. + * + * %TASK_INTERRUPTIBLE - the routine may return early if a signal is + * delivered to the current task. + * + * The current task state is guaranteed to be TASK_RUNNING when this + * routine returns. + * + * Returns 0 when the timer has expired otherwise -EINTR + */ +int __sched schedule_hrtimeout(ktime_t *expires, + const enum hrtimer_mode mode) +{ + return schedule_hrtimeout_range(expires, 0, mode); +} EXPORT_SYMBOL_GPL(schedule_hrtimeout); -- cgit v1.1 From 6976675d94042fbd446231d1bd8b7de71a980ada Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 1 Sep 2008 15:52:40 -0700 Subject: hrtimer: create a "timer_slack" field in the task struct We want to be able to control the default "rounding" that is used by select() and poll() and friends. This is a per process property (so that we can have a "nice" like program to start certain programs with a looser or stricter rounding) that can be set/get via a prctl(). For this purpose, a field called "timer_slack_ns" is added to the task struct. In addition, a field called "default_timer_slack"ns" is added so that tasks easily can temporarily to a more/less accurate slack and then back to the default. The default value of the slack is set to 50 usec; this is significantly less than 2.6.27's average select() and poll() timing error but still allows the kernel to group timers somewhat to preserve power behavior. Applications and admins can override this via the prctl() Signed-off-by: Arjan van de Ven --- kernel/fork.c | 2 ++ kernel/sys.c | 10 ++++++++++ 2 files changed, 12 insertions(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 7ce2ebe..4308d75 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -987,6 +987,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->prev_utime = cputime_zero; p->prev_stime = cputime_zero; + p->default_timer_slack_ns = current->timer_slack_ns; + #ifdef CONFIG_DETECT_SOFTLOCKUP p->last_switch_count = 0; p->last_switch_timestamp = 0; diff --git a/kernel/sys.c b/kernel/sys.c index 038a7bc..1b96401 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1727,6 +1727,16 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, case PR_SET_TSC: error = SET_TSC_CTL(arg2); break; + case PR_GET_TIMERSLACK: + error = current->timer_slack_ns; + break; + case PR_SET_TIMERSLACK: + if (arg2 <= 0) + current->timer_slack_ns = + current->default_timer_slack_ns; + else + current->timer_slack_ns = arg2; + break; default: error = -EINVAL; break; -- cgit v1.1 From 7e6e178ab1548c8d894a77593e757acf4510b8ba Mon Sep 17 00:00:00 2001 From: Pawel MOLL Date: Mon, 1 Sep 2008 10:12:11 +0100 Subject: genirq: irq_chip->startup() usage in setup_irq and set_irq_chained handler This patch clarifies usage of irq_chip->startup() callback: 1. The "if (startup) startup(); else enabled();" code in setup_irq() is unnecessary, as startup() falls back to enabled() via default callbacks, set by irq_chip_set_defaults(). 2. When using set_irq_chained_handler() the startup() was never called, which is not good at all... Fixed. And again - when startup() is not defined the call will fall back to enable() than to unmask() via default callbacks. Signed-off-by: Pawel Moll Acked-by: Benjamin Herrenschmidt Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 2 +- kernel/irq/manage.c | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 964964b..240c64d 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -587,7 +587,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, desc->status &= ~IRQ_DISABLED; desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE; desc->depth = 0; - desc->chip->unmask(irq); + desc->chip->startup(irq); } spin_unlock_irqrestore(&desc->lock, flags); } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ae1b684..9aa3e7b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -397,10 +397,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) if (!(desc->status & IRQ_NOAUTOEN)) { desc->depth = 0; desc->status &= ~IRQ_DISABLED; - if (desc->chip->startup) - desc->chip->startup(irq); - else - desc->chip->enable(irq); + desc->chip->startup(irq); } else /* Undo nested disables: */ desc->depth = 1; -- cgit v1.1 From da8f2e170ea94cc20f8ebbc8ee8d127edb8f12f1 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 7 Sep 2008 10:47:46 -0700 Subject: hrtimer: add a hrtimer_start_range() function this patch adds a _range version of hrtimer_start() so that range timers can be created; the hrtimer_start() function is just a wrapper around this. In addition, hrtimer_start_expires() will now preserve existing ranges. Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 0148300..a022209 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -945,9 +945,10 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) } /** - * hrtimer_start - (re)start an relative timer on the current CPU + * hrtimer_start_range_ns - (re)start an relative timer on the current CPU * @timer: the timer to be added * @tim: expiry time + * @delta_ns: "slack" range for the timer * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) * * Returns: @@ -955,7 +956,8 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) * 1 when the timer was active */ int -hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) +hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_ns, + const enum hrtimer_mode mode) { struct hrtimer_clock_base *base, *new_base; unsigned long flags; @@ -983,7 +985,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) #endif } - hrtimer_set_expires(timer, tim); + hrtimer_set_expires_range_ns(timer, tim, delta_ns); timer_stats_hrtimer_set_start_info(timer); @@ -1016,8 +1018,26 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) return ret; } +EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); + +/** + * hrtimer_start - (re)start an relative timer on the current CPU + * @timer: the timer to be added + * @tim: expiry time + * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) + * + * Returns: + * 0 on success + * 1 when the timer was active + */ +int +hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) +{ + return hrtimer_start_range_ns(timer, tim, 0, mode); +} EXPORT_SYMBOL_GPL(hrtimer_start); + /** * hrtimer_try_to_cancel - try to deactivate a timer * @timer: hrtimer to stop -- cgit v1.1 From 704af52bd13a5d9f3c60c496c68e752fafdfb434 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 7 Sep 2008 16:10:20 -0700 Subject: hrtimer: show the timer ranges in /proc/timer_list to help debugging and visibility of timer ranges, show them in the existing timer list in /proc/timer_list Signed-off-by: Arjan van de Ven --- kernel/time/timer_list.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 5224a32..122ee75 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -65,8 +65,10 @@ print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now) SEQ_printf(m, ", %s/%d", tmp, timer->start_pid); #endif SEQ_printf(m, "\n"); - SEQ_printf(m, " # expires at %Lu nsecs [in %Ld nsecs]\n", + SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", + (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), + (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); } -- cgit v1.1 From 3bd012060f962567aadb52b27b2fc8fdc91102c7 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 8 Sep 2008 08:58:59 -0700 Subject: hrtimer: make the nanosleep() syscall use the per process slack This patch makes the nanosleep() system call use the per process slack value; with this users are able to externally control existing applications to reduce the wakeup rate. Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index a022209..9a4c901 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1563,9 +1563,14 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, struct restart_block *restart; struct hrtimer_sleeper t; int ret = 0; + unsigned long slack; + + slack = current->timer_slack_ns; + if (rt_task(current)) + slack = 0; hrtimer_init_on_stack(&t.timer, clockid, mode); - hrtimer_set_expires(&t.timer, timespec_to_ktime(*rqtp)); + hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); if (do_nanosleep(&t, mode)) goto out; -- cgit v1.1 From ae4b748e81b7e366f04f55229d5e372e372c33af Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 8 Sep 2008 09:03:57 -0700 Subject: hrtimer: make the futex() system call use the per process slack value This patch makes the futex() system call use the per process slack value; with this users are able to externally control existing applications to reduce the wakeup rate. Signed-off-by: Arjan van de Ven --- kernel/futex.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/futex.c b/kernel/futex.c index 4cd5b43..8af1002 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1296,10 +1296,14 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, if (!abs_time) schedule(); else { + unsigned long slack; + slack = current->timer_slack_ns; + if (rt_task(current)) + slack = 0; hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); hrtimer_init_sleeper(&t, current); - hrtimer_set_expires(&t.timer, *abs_time); + hrtimer_set_expires_range_ns(&t.timer, *abs_time, slack); hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS); if (!hrtimer_active(&t.timer)) -- cgit v1.1 From 2e94d1f71f7e4404d997e6fb4f1618aa147d76f9 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 10 Sep 2008 16:06:00 -0700 Subject: hrtimer: peek at the timer queue just before going idle As part of going idle, we already look at the time of the next timer event to determine which C-state to select etc. This patch adds functionality that causes the timers that are past their soft expire time, to fire at this time, before we calculate the next wakeup time. This functionality will thus avoid wakeups by running timers before going idle rather than specially waking up for it. Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 9a4c901..eb2cf98 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1381,6 +1381,36 @@ void hrtimer_interrupt(struct clock_event_device *dev) raise_softirq(HRTIMER_SOFTIRQ); } +/** + * hrtimer_peek_ahead_timers -- run soft-expired timers now + * + * hrtimer_peek_ahead_timers will peek at the timer queue of + * the current cpu and check if there are any timers for which + * the soft expires time has passed. If any such timers exist, + * they are run immediately and then removed from the timer queue. + * + */ +void hrtimer_peek_ahead_timers(void) +{ + unsigned long flags; + struct tick_device *td; + struct clock_event_device *dev; + + if (hrtimer_hres_active()) + return; + + local_irq_save(flags); + td = &__get_cpu_var(tick_cpu_device); + if (!td) + goto out; + dev = td->evtdev; + if (!dev) + goto out; + hrtimer_interrupt(dev); +out: + local_irq_restore(flags); +} + static void run_hrtimer_softirq(struct softirq_action *h) { run_hrtimer_pending(&__get_cpu_var(hrtimer_bases)); -- cgit v1.1 From f06febc96ba8e0af80bcc3eaec0a109e88275fac Mon Sep 17 00:00:00 2001 From: Frank Mayhar Date: Fri, 12 Sep 2008 09:54:39 -0700 Subject: timers: fix itimer/many thread hang Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar Cc: Roland McGrath Cc: Alexey Dobriyan Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/compat.c | 53 ++---- kernel/exit.c | 19 +- kernel/fork.c | 88 +++++---- kernel/itimer.c | 33 +--- kernel/posix-cpu-timers.c | 471 +++++++++++++++++++++++++--------------------- kernel/sched.c | 53 +++++- kernel/sched_fair.c | 1 + kernel/sched_rt.c | 4 +- kernel/signal.c | 8 +- kernel/sys.c | 75 +++----- 10 files changed, 415 insertions(+), 390 deletions(-) (limited to 'kernel') diff --git a/kernel/compat.c b/kernel/compat.c index 32c254a..72650e3 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -23,6 +23,7 @@ #include #include #include +#include #include @@ -150,49 +151,23 @@ asmlinkage long compat_sys_setitimer(int which, return 0; } +static compat_clock_t clock_t_to_compat_clock_t(clock_t x) +{ + return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); +} + asmlinkage long compat_sys_times(struct compat_tms __user *tbuf) { - /* - * In the SMP world we might just be unlucky and have one of - * the times increment as we use it. Since the value is an - * atomically safe type this is just fine. Conceptually its - * as if the syscall took an instant longer to occur. - */ if (tbuf) { + struct tms tms; struct compat_tms tmp; - struct task_struct *tsk = current; - struct task_struct *t; - cputime_t utime, stime, cutime, cstime; - - read_lock(&tasklist_lock); - utime = tsk->signal->utime; - stime = tsk->signal->stime; - t = tsk; - do { - utime = cputime_add(utime, t->utime); - stime = cputime_add(stime, t->stime); - t = next_thread(t); - } while (t != tsk); - - /* - * While we have tasklist_lock read-locked, no dying thread - * can be updating current->signal->[us]time. Instead, - * we got their counts included in the live thread loop. - * However, another thread can come in right now and - * do a wait call that updates current->signal->c[us]time. - * To make sure we always see that pair updated atomically, - * we take the siglock around fetching them. - */ - spin_lock_irq(&tsk->sighand->siglock); - cutime = tsk->signal->cutime; - cstime = tsk->signal->cstime; - spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); - - tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime)); - tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime)); - tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime)); - tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime)); + + do_sys_times(&tms); + /* Convert our struct tms to the compat version. */ + tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); + tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); + tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); + tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); if (copy_to_user(tbuf, &tmp, sizeof(tmp))) return -EFAULT; } diff --git a/kernel/exit.c b/kernel/exit.c index 1639564..40036ac 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -112,8 +112,6 @@ static void __exit_signal(struct task_struct *tsk) * We won't ever get here for the group leader, since it * will have been the last reference on the signal_struct. */ - sig->utime = cputime_add(sig->utime, task_utime(tsk)); - sig->stime = cputime_add(sig->stime, task_stime(tsk)); sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; @@ -122,7 +120,6 @@ static void __exit_signal(struct task_struct *tsk) sig->inblock += task_io_get_inblock(tsk); sig->oublock += task_io_get_oublock(tsk); task_io_accounting_add(&sig->ioac, &tsk->ioac); - sig->sum_sched_runtime += tsk->se.sum_exec_runtime; sig = NULL; /* Marker for below. */ } @@ -1294,6 +1291,7 @@ static int wait_task_zombie(struct task_struct *p, int options, if (likely(!traced)) { struct signal_struct *psig; struct signal_struct *sig; + struct task_cputime cputime; /* * The resource counters for the group leader are in its @@ -1309,20 +1307,23 @@ static int wait_task_zombie(struct task_struct *p, int options, * need to protect the access to p->parent->signal fields, * as other threads in the parent group can be right * here reaping other children at the same time. + * + * We use thread_group_cputime() to get times for the thread + * group, which consolidates times for all threads in the + * group including the group leader. */ spin_lock_irq(&p->parent->sighand->siglock); psig = p->parent->signal; sig = p->signal; + thread_group_cputime(p, &cputime); psig->cutime = cputime_add(psig->cutime, - cputime_add(p->utime, - cputime_add(sig->utime, - sig->cutime))); + cputime_add(cputime.utime, + sig->cutime)); psig->cstime = cputime_add(psig->cstime, - cputime_add(p->stime, - cputime_add(sig->stime, - sig->cstime))); + cputime_add(cputime.stime, + sig->cstime)); psig->cgtime = cputime_add(psig->cgtime, cputime_add(p->gtime, diff --git a/kernel/fork.c b/kernel/fork.c index 7ce2ebe..a8ac2ef 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -759,15 +759,44 @@ void __cleanup_sighand(struct sighand_struct *sighand) kmem_cache_free(sighand_cachep, sighand); } + +/* + * Initialize POSIX timer handling for a thread group. + */ +static void posix_cpu_timers_init_group(struct signal_struct *sig) +{ + /* Thread group counters. */ + thread_group_cputime_init(sig); + + /* Expiration times and increments. */ + sig->it_virt_expires = cputime_zero; + sig->it_virt_incr = cputime_zero; + sig->it_prof_expires = cputime_zero; + sig->it_prof_incr = cputime_zero; + + /* Cached expiration times. */ + sig->cputime_expires.prof_exp = cputime_zero; + sig->cputime_expires.virt_exp = cputime_zero; + sig->cputime_expires.sched_exp = 0; + + /* The timer lists. */ + INIT_LIST_HEAD(&sig->cpu_timers[0]); + INIT_LIST_HEAD(&sig->cpu_timers[1]); + INIT_LIST_HEAD(&sig->cpu_timers[2]); +} + static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) { struct signal_struct *sig; int ret; if (clone_flags & CLONE_THREAD) { - atomic_inc(¤t->signal->count); - atomic_inc(¤t->signal->live); - return 0; + ret = thread_group_cputime_clone_thread(current, tsk); + if (likely(!ret)) { + atomic_inc(¤t->signal->count); + atomic_inc(¤t->signal->live); + } + return ret; } sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); tsk->signal = sig; @@ -795,15 +824,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->it_real_incr.tv64 = 0; sig->real_timer.function = it_real_fn; - sig->it_virt_expires = cputime_zero; - sig->it_virt_incr = cputime_zero; - sig->it_prof_expires = cputime_zero; - sig->it_prof_incr = cputime_zero; - sig->leader = 0; /* session leadership doesn't inherit */ sig->tty_old_pgrp = NULL; - sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; + sig->cutime = sig->cstime = cputime_zero; sig->gtime = cputime_zero; sig->cgtime = cputime_zero; sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; @@ -820,14 +844,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim); task_unlock(current->group_leader); - if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) { - /* - * New sole thread in the process gets an expiry time - * of the whole CPU time limit. - */ - tsk->it_prof_expires = - secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur); - } + posix_cpu_timers_init_group(sig); + acct_init_pacct(&sig->pacct); tty_audit_fork(sig); @@ -837,6 +855,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) void __cleanup_signal(struct signal_struct *sig) { + thread_group_cputime_free(sig); exit_thread_group_keys(sig); kmem_cache_free(signal_cachep, sig); } @@ -886,6 +905,19 @@ void mm_init_owner(struct mm_struct *mm, struct task_struct *p) #endif /* CONFIG_MM_OWNER */ /* + * Initialize POSIX timer handling for a single task. + */ +static void posix_cpu_timers_init(struct task_struct *tsk) +{ + tsk->cputime_expires.prof_exp = cputime_zero; + tsk->cputime_expires.virt_exp = cputime_zero; + tsk->cputime_expires.sched_exp = 0; + INIT_LIST_HEAD(&tsk->cpu_timers[0]); + INIT_LIST_HEAD(&tsk->cpu_timers[1]); + INIT_LIST_HEAD(&tsk->cpu_timers[2]); +} + +/* * This creates a new process as a copy of the old one, * but does not actually start it yet. * @@ -995,12 +1027,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, task_io_accounting_init(&p->ioac); acct_clear_integrals(p); - p->it_virt_expires = cputime_zero; - p->it_prof_expires = cputime_zero; - p->it_sched_expires = 0; - INIT_LIST_HEAD(&p->cpu_timers[0]); - INIT_LIST_HEAD(&p->cpu_timers[1]); - INIT_LIST_HEAD(&p->cpu_timers[2]); + posix_cpu_timers_init(p); p->lock_depth = -1; /* -1 = no lock */ do_posix_clock_monotonic_gettime(&p->start_time); @@ -1201,21 +1228,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (clone_flags & CLONE_THREAD) { p->group_leader = current->group_leader; list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group); - - if (!cputime_eq(current->signal->it_virt_expires, - cputime_zero) || - !cputime_eq(current->signal->it_prof_expires, - cputime_zero) || - current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY || - !list_empty(¤t->signal->cpu_timers[0]) || - !list_empty(¤t->signal->cpu_timers[1]) || - !list_empty(¤t->signal->cpu_timers[2])) { - /* - * Have child wake up on its first tick to check - * for process CPU timers. - */ - p->it_prof_expires = jiffies_to_cputime(1); - } } if (likely(p->pid)) { diff --git a/kernel/itimer.c b/kernel/itimer.c index ab98274..db7c358 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -55,17 +55,15 @@ int do_getitimer(int which, struct itimerval *value) spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: - read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; if (!cputime_eq(cval, cputime_zero)) { - struct task_struct *t = tsk; - cputime_t utime = tsk->signal->utime; - do { - utime = cputime_add(utime, t->utime); - t = next_thread(t); - } while (t != tsk); + struct task_cputime cputime; + cputime_t utime; + + thread_group_cputime(tsk, &cputime); + utime = cputime.utime; if (cputime_le(cval, utime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { @@ -73,25 +71,19 @@ int do_getitimer(int which, struct itimerval *value) } } spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; case ITIMER_PROF: - read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; if (!cputime_eq(cval, cputime_zero)) { - struct task_struct *t = tsk; - cputime_t ptime = cputime_add(tsk->signal->utime, - tsk->signal->stime); - do { - ptime = cputime_add(ptime, - cputime_add(t->utime, - t->stime)); - t = next_thread(t); - } while (t != tsk); + struct task_cputime times; + cputime_t ptime; + + thread_group_cputime(tsk, ×); + ptime = cputime_add(times.utime, times.stime); if (cputime_le(cval, ptime)) { /* about to fire */ cval = jiffies_to_cputime(1); } else { @@ -99,7 +91,6 @@ int do_getitimer(int which, struct itimerval *value) } } spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); cputime_to_timeval(cval, &value->it_value); cputime_to_timeval(cinterval, &value->it_interval); break; @@ -185,7 +176,6 @@ again: case ITIMER_VIRTUAL: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); - read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_virt_expires; cinterval = tsk->signal->it_virt_incr; @@ -200,7 +190,6 @@ again: tsk->signal->it_virt_expires = nval; tsk->signal->it_virt_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); @@ -209,7 +198,6 @@ again: case ITIMER_PROF: nval = timeval_to_cputime(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); - read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); cval = tsk->signal->it_prof_expires; cinterval = tsk->signal->it_prof_incr; @@ -224,7 +212,6 @@ again: tsk->signal->it_prof_expires = nval; tsk->signal->it_prof_incr = ninterval; spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index c42a03a..dba1c33 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -8,6 +8,99 @@ #include #include +#ifdef CONFIG_SMP +/* + * Allocate the thread_group_cputime structure appropriately for SMP kernels + * and fill in the current values of the fields. Called from copy_signal() + * via thread_group_cputime_clone_thread() when adding a second or subsequent + * thread to a thread group. Assumes interrupts are enabled when called. + */ +int thread_group_cputime_alloc_smp(struct task_struct *tsk) +{ + struct signal_struct *sig = tsk->signal; + struct task_cputime *cputime; + + /* + * If we have multiple threads and we don't already have a + * per-CPU task_cputime struct, allocate one and fill it in with + * the times accumulated so far. + */ + if (sig->cputime.totals) + return 0; + cputime = alloc_percpu(struct task_cputime); + if (cputime == NULL) + return -ENOMEM; + read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); + if (sig->cputime.totals) { + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + free_percpu(cputime); + return 0; + } + sig->cputime.totals = cputime; + cputime = per_cpu_ptr(sig->cputime.totals, get_cpu()); + cputime->utime = tsk->utime; + cputime->stime = tsk->stime; + cputime->sum_exec_runtime = tsk->se.sum_exec_runtime; + put_cpu_no_resched(); + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + return 0; +} + +/** + * thread_group_cputime_smp - Sum the thread group time fields across all CPUs. + * + * @tsk: The task we use to identify the thread group. + * @times: task_cputime structure in which we return the summed fields. + * + * Walk the list of CPUs to sum the per-CPU time fields in the thread group + * time structure. + */ +void thread_group_cputime_smp( + struct task_struct *tsk, + struct task_cputime *times) +{ + struct signal_struct *sig; + int i; + struct task_cputime *tot; + + sig = tsk->signal; + if (unlikely(!sig) || !sig->cputime.totals) { + times->utime = tsk->utime; + times->stime = tsk->stime; + times->sum_exec_runtime = tsk->se.sum_exec_runtime; + return; + } + times->stime = times->utime = cputime_zero; + times->sum_exec_runtime = 0; + for_each_possible_cpu(i) { + tot = per_cpu_ptr(tsk->signal->cputime.totals, i); + times->utime = cputime_add(times->utime, tot->utime); + times->stime = cputime_add(times->stime, tot->stime); + times->sum_exec_runtime += tot->sum_exec_runtime; + } +} + +#endif /* CONFIG_SMP */ + +/* + * Called after updating RLIMIT_CPU to set timer expiration if necessary. + */ +void update_rlimit_cpu(unsigned long rlim_new) +{ + cputime_t cputime; + + cputime = secs_to_cputime(rlim_new); + if (cputime_eq(current->signal->it_prof_expires, cputime_zero) || + cputime_lt(current->signal->it_prof_expires, cputime)) { + spin_lock_irq(¤t->sighand->siglock); + set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); + spin_unlock_irq(¤t->sighand->siglock); + } +} + static int check_clock(const clockid_t which_clock) { int error = 0; @@ -158,10 +251,6 @@ static inline cputime_t virt_ticks(struct task_struct *p) { return p->utime; } -static inline unsigned long long sched_ns(struct task_struct *p) -{ - return task_sched_runtime(p); -} int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) { @@ -211,7 +300,7 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, cpu->cpu = virt_ticks(p); break; case CPUCLOCK_SCHED: - cpu->sched = sched_ns(p); + cpu->sched = task_sched_runtime(p); break; } return 0; @@ -226,31 +315,20 @@ static int cpu_clock_sample_group_locked(unsigned int clock_idx, struct task_struct *p, union cpu_time_count *cpu) { - struct task_struct *t = p; - switch (clock_idx) { + struct task_cputime cputime; + + thread_group_cputime(p, &cputime); + switch (clock_idx) { default: return -EINVAL; case CPUCLOCK_PROF: - cpu->cpu = cputime_add(p->signal->utime, p->signal->stime); - do { - cpu->cpu = cputime_add(cpu->cpu, prof_ticks(t)); - t = next_thread(t); - } while (t != p); + cpu->cpu = cputime_add(cputime.utime, cputime.stime); break; case CPUCLOCK_VIRT: - cpu->cpu = p->signal->utime; - do { - cpu->cpu = cputime_add(cpu->cpu, virt_ticks(t)); - t = next_thread(t); - } while (t != p); + cpu->cpu = cputime.utime; break; case CPUCLOCK_SCHED: - cpu->sched = p->signal->sum_sched_runtime; - /* Add in each other live thread. */ - while ((t = next_thread(t)) != p) { - cpu->sched += t->se.sum_exec_runtime; - } - cpu->sched += sched_ns(p); + cpu->sched = thread_group_sched_runtime(p); break; } return 0; @@ -471,80 +549,11 @@ void posix_cpu_timers_exit(struct task_struct *tsk) } void posix_cpu_timers_exit_group(struct task_struct *tsk) { - cleanup_timers(tsk->signal->cpu_timers, - cputime_add(tsk->utime, tsk->signal->utime), - cputime_add(tsk->stime, tsk->signal->stime), - tsk->se.sum_exec_runtime + tsk->signal->sum_sched_runtime); -} - - -/* - * Set the expiry times of all the threads in the process so one of them - * will go off before the process cumulative expiry total is reached. - */ -static void process_timer_rebalance(struct task_struct *p, - unsigned int clock_idx, - union cpu_time_count expires, - union cpu_time_count val) -{ - cputime_t ticks, left; - unsigned long long ns, nsleft; - struct task_struct *t = p; - unsigned int nthreads = atomic_read(&p->signal->live); - - if (!nthreads) - return; + struct task_cputime cputime; - switch (clock_idx) { - default: - BUG(); - break; - case CPUCLOCK_PROF: - left = cputime_div_non_zero(cputime_sub(expires.cpu, val.cpu), - nthreads); - do { - if (likely(!(t->flags & PF_EXITING))) { - ticks = cputime_add(prof_ticks(t), left); - if (cputime_eq(t->it_prof_expires, - cputime_zero) || - cputime_gt(t->it_prof_expires, ticks)) { - t->it_prof_expires = ticks; - } - } - t = next_thread(t); - } while (t != p); - break; - case CPUCLOCK_VIRT: - left = cputime_div_non_zero(cputime_sub(expires.cpu, val.cpu), - nthreads); - do { - if (likely(!(t->flags & PF_EXITING))) { - ticks = cputime_add(virt_ticks(t), left); - if (cputime_eq(t->it_virt_expires, - cputime_zero) || - cputime_gt(t->it_virt_expires, ticks)) { - t->it_virt_expires = ticks; - } - } - t = next_thread(t); - } while (t != p); - break; - case CPUCLOCK_SCHED: - nsleft = expires.sched - val.sched; - do_div(nsleft, nthreads); - nsleft = max_t(unsigned long long, nsleft, 1); - do { - if (likely(!(t->flags & PF_EXITING))) { - ns = t->se.sum_exec_runtime + nsleft; - if (t->it_sched_expires == 0 || - t->it_sched_expires > ns) { - t->it_sched_expires = ns; - } - } - t = next_thread(t); - } while (t != p); - break; - } + thread_group_cputime(tsk, &cputime); + cleanup_timers(tsk->signal->cpu_timers, + cputime.utime, cputime.stime, cputime.sum_exec_runtime); } static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) @@ -608,29 +617,32 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) default: BUG(); case CPUCLOCK_PROF: - if (cputime_eq(p->it_prof_expires, + if (cputime_eq(p->cputime_expires.prof_exp, cputime_zero) || - cputime_gt(p->it_prof_expires, + cputime_gt(p->cputime_expires.prof_exp, nt->expires.cpu)) - p->it_prof_expires = nt->expires.cpu; + p->cputime_expires.prof_exp = + nt->expires.cpu; break; case CPUCLOCK_VIRT: - if (cputime_eq(p->it_virt_expires, + if (cputime_eq(p->cputime_expires.virt_exp, cputime_zero) || - cputime_gt(p->it_virt_expires, + cputime_gt(p->cputime_expires.virt_exp, nt->expires.cpu)) - p->it_virt_expires = nt->expires.cpu; + p->cputime_expires.virt_exp = + nt->expires.cpu; break; case CPUCLOCK_SCHED: - if (p->it_sched_expires == 0 || - p->it_sched_expires > nt->expires.sched) - p->it_sched_expires = nt->expires.sched; + if (p->cputime_expires.sched_exp == 0 || + p->cputime_expires.sched_exp > + nt->expires.sched) + p->cputime_expires.sched_exp = + nt->expires.sched; break; } } else { /* - * For a process timer, we must balance - * all the live threads' expirations. + * For a process timer, set the cached expiration time. */ switch (CPUCLOCK_WHICH(timer->it_clock)) { default: @@ -641,7 +653,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) cputime_lt(p->signal->it_virt_expires, timer->it.cpu.expires.cpu)) break; - goto rebalance; + p->signal->cputime_expires.virt_exp = + timer->it.cpu.expires.cpu; + break; case CPUCLOCK_PROF: if (!cputime_eq(p->signal->it_prof_expires, cputime_zero) && @@ -652,13 +666,12 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) if (i != RLIM_INFINITY && i <= cputime_to_secs(timer->it.cpu.expires.cpu)) break; - goto rebalance; + p->signal->cputime_expires.prof_exp = + timer->it.cpu.expires.cpu; + break; case CPUCLOCK_SCHED: - rebalance: - process_timer_rebalance( - timer->it.cpu.task, - CPUCLOCK_WHICH(timer->it_clock), - timer->it.cpu.expires, now); + p->signal->cputime_expires.sched_exp = + timer->it.cpu.expires.sched; break; } } @@ -969,13 +982,13 @@ static void check_thread_timers(struct task_struct *tsk, struct signal_struct *const sig = tsk->signal; maxfire = 20; - tsk->it_prof_expires = cputime_zero; + tsk->cputime_expires.prof_exp = cputime_zero; while (!list_empty(timers)) { struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) { - tsk->it_prof_expires = t->expires.cpu; + tsk->cputime_expires.prof_exp = t->expires.cpu; break; } t->firing = 1; @@ -984,13 +997,13 @@ static void check_thread_timers(struct task_struct *tsk, ++timers; maxfire = 20; - tsk->it_virt_expires = cputime_zero; + tsk->cputime_expires.virt_exp = cputime_zero; while (!list_empty(timers)) { struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) { - tsk->it_virt_expires = t->expires.cpu; + tsk->cputime_expires.virt_exp = t->expires.cpu; break; } t->firing = 1; @@ -999,13 +1012,13 @@ static void check_thread_timers(struct task_struct *tsk, ++timers; maxfire = 20; - tsk->it_sched_expires = 0; + tsk->cputime_expires.sched_exp = 0; while (!list_empty(timers)) { struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) { - tsk->it_sched_expires = t->expires.sched; + tsk->cputime_expires.sched_exp = t->expires.sched; break; } t->firing = 1; @@ -1055,10 +1068,10 @@ static void check_process_timers(struct task_struct *tsk, { int maxfire; struct signal_struct *const sig = tsk->signal; - cputime_t utime, stime, ptime, virt_expires, prof_expires; + cputime_t utime, ptime, virt_expires, prof_expires; unsigned long long sum_sched_runtime, sched_expires; - struct task_struct *t; struct list_head *timers = sig->cpu_timers; + struct task_cputime cputime; /* * Don't sample the current process CPU clocks if there are no timers. @@ -1074,18 +1087,10 @@ static void check_process_timers(struct task_struct *tsk, /* * Collect the current process totals. */ - utime = sig->utime; - stime = sig->stime; - sum_sched_runtime = sig->sum_sched_runtime; - t = tsk; - do { - utime = cputime_add(utime, t->utime); - stime = cputime_add(stime, t->stime); - sum_sched_runtime += t->se.sum_exec_runtime; - t = next_thread(t); - } while (t != tsk); - ptime = cputime_add(utime, stime); - + thread_group_cputime(tsk, &cputime); + utime = cputime.utime; + ptime = cputime_add(utime, cputime.stime); + sum_sched_runtime = cputime.sum_exec_runtime; maxfire = 20; prof_expires = cputime_zero; while (!list_empty(timers)) { @@ -1193,60 +1198,18 @@ static void check_process_timers(struct task_struct *tsk, } } - if (!cputime_eq(prof_expires, cputime_zero) || - !cputime_eq(virt_expires, cputime_zero) || - sched_expires != 0) { - /* - * Rebalance the threads' expiry times for the remaining - * process CPU timers. - */ - - cputime_t prof_left, virt_left, ticks; - unsigned long long sched_left, sched; - const unsigned int nthreads = atomic_read(&sig->live); - - if (!nthreads) - return; - - prof_left = cputime_sub(prof_expires, utime); - prof_left = cputime_sub(prof_left, stime); - prof_left = cputime_div_non_zero(prof_left, nthreads); - virt_left = cputime_sub(virt_expires, utime); - virt_left = cputime_div_non_zero(virt_left, nthreads); - if (sched_expires) { - sched_left = sched_expires - sum_sched_runtime; - do_div(sched_left, nthreads); - sched_left = max_t(unsigned long long, sched_left, 1); - } else { - sched_left = 0; - } - t = tsk; - do { - if (unlikely(t->flags & PF_EXITING)) - continue; - - ticks = cputime_add(cputime_add(t->utime, t->stime), - prof_left); - if (!cputime_eq(prof_expires, cputime_zero) && - (cputime_eq(t->it_prof_expires, cputime_zero) || - cputime_gt(t->it_prof_expires, ticks))) { - t->it_prof_expires = ticks; - } - - ticks = cputime_add(t->utime, virt_left); - if (!cputime_eq(virt_expires, cputime_zero) && - (cputime_eq(t->it_virt_expires, cputime_zero) || - cputime_gt(t->it_virt_expires, ticks))) { - t->it_virt_expires = ticks; - } - - sched = t->se.sum_exec_runtime + sched_left; - if (sched_expires && (t->it_sched_expires == 0 || - t->it_sched_expires > sched)) { - t->it_sched_expires = sched; - } - } while ((t = next_thread(t)) != tsk); - } + if (!cputime_eq(prof_expires, cputime_zero) && + (cputime_eq(sig->cputime_expires.prof_exp, cputime_zero) || + cputime_gt(sig->cputime_expires.prof_exp, prof_expires))) + sig->cputime_expires.prof_exp = prof_expires; + if (!cputime_eq(virt_expires, cputime_zero) && + (cputime_eq(sig->cputime_expires.virt_exp, cputime_zero) || + cputime_gt(sig->cputime_expires.virt_exp, virt_expires))) + sig->cputime_expires.virt_exp = virt_expires; + if (sched_expires != 0 && + (sig->cputime_expires.sched_exp == 0 || + sig->cputime_expires.sched_exp > sched_expires)) + sig->cputime_expires.sched_exp = sched_expires; } /* @@ -1314,6 +1277,78 @@ out: ++timer->it_requeue_pending; } +/** + * task_cputime_zero - Check a task_cputime struct for all zero fields. + * + * @cputime: The struct to compare. + * + * Checks @cputime to see if all fields are zero. Returns true if all fields + * are zero, false if any field is nonzero. + */ +static inline int task_cputime_zero(const struct task_cputime *cputime) +{ + if (cputime_eq(cputime->utime, cputime_zero) && + cputime_eq(cputime->stime, cputime_zero) && + cputime->sum_exec_runtime == 0) + return 1; + return 0; +} + +/** + * task_cputime_expired - Compare two task_cputime entities. + * + * @sample: The task_cputime structure to be checked for expiration. + * @expires: Expiration times, against which @sample will be checked. + * + * Checks @sample against @expires to see if any field of @sample has expired. + * Returns true if any field of the former is greater than the corresponding + * field of the latter if the latter field is set. Otherwise returns false. + */ +static inline int task_cputime_expired(const struct task_cputime *sample, + const struct task_cputime *expires) +{ + if (!cputime_eq(expires->utime, cputime_zero) && + cputime_ge(sample->utime, expires->utime)) + return 1; + if (!cputime_eq(expires->stime, cputime_zero) && + cputime_ge(cputime_add(sample->utime, sample->stime), + expires->stime)) + return 1; + if (expires->sum_exec_runtime != 0 && + sample->sum_exec_runtime >= expires->sum_exec_runtime) + return 1; + return 0; +} + +/** + * fastpath_timer_check - POSIX CPU timers fast path. + * + * @tsk: The task (thread) being checked. + * @sig: The signal pointer for that task. + * + * If there are no timers set return false. Otherwise snapshot the task and + * thread group timers, then compare them with the corresponding expiration + # times. Returns true if a timer has expired, else returns false. + */ +static inline int fastpath_timer_check(struct task_struct *tsk, + struct signal_struct *sig) +{ + struct task_cputime task_sample = { + .utime = tsk->utime, + .stime = tsk->stime, + .sum_exec_runtime = tsk->se.sum_exec_runtime + }; + struct task_cputime group_sample; + + if (task_cputime_zero(&tsk->cputime_expires) && + task_cputime_zero(&sig->cputime_expires)) + return 0; + if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) + return 1; + thread_group_cputime(tsk, &group_sample); + return task_cputime_expired(&group_sample, &sig->cputime_expires); +} + /* * This is called from the timer interrupt handler. The irq handler has * already updated our counts. We need to check if any timers fire now. @@ -1323,30 +1358,29 @@ void run_posix_cpu_timers(struct task_struct *tsk) { LIST_HEAD(firing); struct k_itimer *timer, *next; + struct signal_struct *sig; + struct sighand_struct *sighand; + unsigned long flags; BUG_ON(!irqs_disabled()); -#define UNEXPIRED(clock) \ - (cputime_eq(tsk->it_##clock##_expires, cputime_zero) || \ - cputime_lt(clock##_ticks(tsk), tsk->it_##clock##_expires)) - - if (UNEXPIRED(prof) && UNEXPIRED(virt) && - (tsk->it_sched_expires == 0 || - tsk->se.sum_exec_runtime < tsk->it_sched_expires)) - return; - -#undef UNEXPIRED - + /* Pick up tsk->signal and make sure it's valid. */ + sig = tsk->signal; /* - * Double-check with locks held. + * The fast path checks that there are no expired thread or thread + * group timers. If that's so, just return. Also check that + * tsk->signal is non-NULL; this probably can't happen but cover the + * possibility anyway. */ - read_lock(&tasklist_lock); - if (likely(tsk->signal != NULL)) { - spin_lock(&tsk->sighand->siglock); - + if (unlikely(!sig) || !fastpath_timer_check(tsk, sig)) { + return; + } + sighand = lock_task_sighand(tsk, &flags); + if (likely(sighand)) { /* - * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N] - * all the timers that are firing, and put them on the firing list. + * Here we take off tsk->signal->cpu_timers[N] and + * tsk->cpu_timers[N] all the timers that are firing, and + * put them on the firing list. */ check_thread_timers(tsk, &firing); check_process_timers(tsk, &firing); @@ -1359,9 +1393,8 @@ void run_posix_cpu_timers(struct task_struct *tsk) * that gets the timer lock before we do will give it up and * spin until we've taken care of that timer below. */ - spin_unlock(&tsk->sighand->siglock); } - read_unlock(&tasklist_lock); + unlock_task_sighand(tsk, &flags); /* * Now that all the timers on our list have the firing flag, @@ -1389,10 +1422,9 @@ void run_posix_cpu_timers(struct task_struct *tsk) /* * Set one of the process-wide special case CPU timers. - * The tasklist_lock and tsk->sighand->siglock must be held by the caller. - * The oldval argument is null for the RLIMIT_CPU timer, where *newval is - * absolute; non-null for ITIMER_*, where *newval is relative and we update - * it to be absolute, *oldval is absolute and we update it to be relative. + * The tsk->sighand->siglock must be held by the caller. + * The *newval argument is relative and we update it to be absolute, *oldval + * is absolute and we update it to be relative. */ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, cputime_t *newval, cputime_t *oldval) @@ -1435,13 +1467,14 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, cputime_ge(list_first_entry(head, struct cpu_timer_list, entry)->expires.cpu, *newval)) { - /* - * Rejigger each thread's expiry time so that one will - * notice before we hit the process-cumulative expiry time. - */ - union cpu_time_count expires = { .sched = 0 }; - expires.cpu = *newval; - process_timer_rebalance(tsk, clock_idx, expires, now); + switch (clock_idx) { + case CPUCLOCK_PROF: + tsk->signal->cputime_expires.prof_exp = *newval; + break; + case CPUCLOCK_VIRT: + tsk->signal->cputime_expires.virt_exp = *newval; + break; + } } } diff --git a/kernel/sched.c b/kernel/sched.c index cc1f81b..c51b5d2 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4037,23 +4037,56 @@ DEFINE_PER_CPU(struct kernel_stat, kstat); EXPORT_PER_CPU_SYMBOL(kstat); /* + * Return any ns on the sched_clock that have not yet been banked in + * @p in case that task is currently running. + * + * Called with task_rq_lock() held on @rq. + */ +static unsigned long long task_delta_exec(struct task_struct *p, struct rq *rq) +{ + if (task_current(rq, p)) { + u64 delta_exec; + + update_rq_clock(rq); + delta_exec = rq->clock - p->se.exec_start; + if ((s64)delta_exec > 0) + return delta_exec; + } + return 0; +} + +/* * Return p->sum_exec_runtime plus any more ns on the sched_clock * that have not yet been banked in case the task is currently running. */ unsigned long long task_sched_runtime(struct task_struct *p) { unsigned long flags; - u64 ns, delta_exec; + u64 ns; struct rq *rq; rq = task_rq_lock(p, &flags); - ns = p->se.sum_exec_runtime; - if (task_current(rq, p)) { - update_rq_clock(rq); - delta_exec = rq->clock - p->se.exec_start; - if ((s64)delta_exec > 0) - ns += delta_exec; - } + ns = p->se.sum_exec_runtime + task_delta_exec(p, rq); + task_rq_unlock(rq, &flags); + + return ns; +} + +/* + * Return sum_exec_runtime for the thread group plus any more ns on the + * sched_clock that have not yet been banked in case the task is currently + * running. + */ +unsigned long long thread_group_sched_runtime(struct task_struct *p) +{ + unsigned long flags; + u64 ns; + struct rq *rq; + struct task_cputime totals; + + rq = task_rq_lock(p, &flags); + thread_group_cputime(p, &totals); + ns = totals.sum_exec_runtime + task_delta_exec(p, rq); task_rq_unlock(rq, &flags); return ns; @@ -4070,6 +4103,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime) cputime64_t tmp; p->utime = cputime_add(p->utime, cputime); + account_group_user_time(p, cputime); /* Add user time to cpustat. */ tmp = cputime_to_cputime64(cputime); @@ -4094,6 +4128,7 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime) tmp = cputime_to_cputime64(cputime); p->utime = cputime_add(p->utime, cputime); + account_group_user_time(p, cputime); p->gtime = cputime_add(p->gtime, cputime); cpustat->user = cputime64_add(cpustat->user, tmp); @@ -4129,6 +4164,7 @@ void account_system_time(struct task_struct *p, int hardirq_offset, } p->stime = cputime_add(p->stime, cputime); + account_group_system_time(p, cputime); /* Add system time to cpustat. */ tmp = cputime_to_cputime64(cputime); @@ -4170,6 +4206,7 @@ void account_steal_time(struct task_struct *p, cputime_t steal) if (p == rq->idle) { p->stime = cputime_add(p->stime, steal); + account_group_system_time(p, steal); if (atomic_read(&rq->nr_iowait) > 0) cpustat->iowait = cputime64_add(cpustat->iowait, tmp); else diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index fb8994c..99aa31a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -507,6 +507,7 @@ static void update_curr(struct cfs_rq *cfs_rq) struct task_struct *curtask = task_of(curr); cpuacct_charge(curtask, delta_exec); + account_group_exec_runtime(curtask, delta_exec); } } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 5523107..8375e69 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -483,6 +483,8 @@ static void update_curr_rt(struct rq *rq) schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); curr->se.sum_exec_runtime += delta_exec; + account_group_exec_runtime(curr, delta_exec); + curr->se.exec_start = rq->clock; cpuacct_charge(curr, delta_exec); @@ -1412,7 +1414,7 @@ static void watchdog(struct rq *rq, struct task_struct *p) p->rt.timeout++; next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); if (p->rt.timeout > next) - p->it_sched_expires = p->se.sum_exec_runtime; + p->cputime_expires.sched_exp = p->se.sum_exec_runtime; } } diff --git a/kernel/signal.c b/kernel/signal.c index e661b01..6eea582 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1338,6 +1338,7 @@ int do_notify_parent(struct task_struct *tsk, int sig) struct siginfo info; unsigned long flags; struct sighand_struct *psig; + struct task_cputime cputime; int ret = sig; BUG_ON(sig == -1); @@ -1368,10 +1369,9 @@ int do_notify_parent(struct task_struct *tsk, int sig) info.si_uid = tsk->uid; - info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, - tsk->signal->utime)); - info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, - tsk->signal->stime)); + thread_group_cputime(tsk, &cputime); + info.si_utime = cputime_to_jiffies(cputime.utime); + info.si_stime = cputime_to_jiffies(cputime.stime); info.si_status = tsk->exit_code & 0x7f; if (tsk->exit_code & 0x80) diff --git a/kernel/sys.c b/kernel/sys.c index 038a7bc..d046a7a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -853,38 +853,28 @@ asmlinkage long sys_setfsgid(gid_t gid) return old_fsgid; } +void do_sys_times(struct tms *tms) +{ + struct task_cputime cputime; + cputime_t cutime, cstime; + + spin_lock_irq(¤t->sighand->siglock); + thread_group_cputime(current, &cputime); + cutime = current->signal->cutime; + cstime = current->signal->cstime; + spin_unlock_irq(¤t->sighand->siglock); + tms->tms_utime = cputime_to_clock_t(cputime.utime); + tms->tms_stime = cputime_to_clock_t(cputime.stime); + tms->tms_cutime = cputime_to_clock_t(cutime); + tms->tms_cstime = cputime_to_clock_t(cstime); +} + asmlinkage long sys_times(struct tms __user * tbuf) { - /* - * In the SMP world we might just be unlucky and have one of - * the times increment as we use it. Since the value is an - * atomically safe type this is just fine. Conceptually its - * as if the syscall took an instant longer to occur. - */ if (tbuf) { struct tms tmp; - struct task_struct *tsk = current; - struct task_struct *t; - cputime_t utime, stime, cutime, cstime; - - spin_lock_irq(&tsk->sighand->siglock); - utime = tsk->signal->utime; - stime = tsk->signal->stime; - t = tsk; - do { - utime = cputime_add(utime, t->utime); - stime = cputime_add(stime, t->stime); - t = next_thread(t); - } while (t != tsk); - - cutime = tsk->signal->cutime; - cstime = tsk->signal->cstime; - spin_unlock_irq(&tsk->sighand->siglock); - - tmp.tms_utime = cputime_to_clock_t(utime); - tmp.tms_stime = cputime_to_clock_t(stime); - tmp.tms_cutime = cputime_to_clock_t(cutime); - tmp.tms_cstime = cputime_to_clock_t(cstime); + + do_sys_times(&tmp); if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) return -EFAULT; } @@ -1445,7 +1435,6 @@ asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *r asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) { struct rlimit new_rlim, *old_rlim; - unsigned long it_prof_secs; int retval; if (resource >= RLIM_NLIMITS) @@ -1491,18 +1480,7 @@ asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) if (new_rlim.rlim_cur == RLIM_INFINITY) goto out; - it_prof_secs = cputime_to_secs(current->signal->it_prof_expires); - if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) { - unsigned long rlim_cur = new_rlim.rlim_cur; - cputime_t cputime; - - cputime = secs_to_cputime(rlim_cur); - read_lock(&tasklist_lock); - spin_lock_irq(¤t->sighand->siglock); - set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); - spin_unlock_irq(¤t->sighand->siglock); - read_unlock(&tasklist_lock); - } + update_rlimit_cpu(new_rlim.rlim_cur); out: return 0; } @@ -1540,11 +1518,8 @@ out: * */ -static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r, - cputime_t *utimep, cputime_t *stimep) +static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) { - *utimep = cputime_add(*utimep, t->utime); - *stimep = cputime_add(*stimep, t->stime); r->ru_nvcsw += t->nvcsw; r->ru_nivcsw += t->nivcsw; r->ru_minflt += t->min_flt; @@ -1558,12 +1533,13 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; cputime_t utime, stime; + struct task_cputime cputime; memset((char *) r, 0, sizeof *r); utime = stime = cputime_zero; if (who == RUSAGE_THREAD) { - accumulate_thread_rusage(p, r, &utime, &stime); + accumulate_thread_rusage(p, r); goto out; } @@ -1586,8 +1562,9 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) break; case RUSAGE_SELF: - utime = cputime_add(utime, p->signal->utime); - stime = cputime_add(stime, p->signal->stime); + thread_group_cputime(p, &cputime); + utime = cputime_add(utime, cputime.utime); + stime = cputime_add(stime, cputime.stime); r->ru_nvcsw += p->signal->nvcsw; r->ru_nivcsw += p->signal->nivcsw; r->ru_minflt += p->signal->min_flt; @@ -1596,7 +1573,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += p->signal->oublock; t = p; do { - accumulate_thread_rusage(t, r, &utime, &stime); + accumulate_thread_rusage(t, r); t = next_thread(t); } while (t != p); break; -- cgit v1.1 From 430b5294bd72c085c730e1e4b86580f164d976bf Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 14 Sep 2008 16:33:01 +0200 Subject: timers: fix itimer/many thread hang, fix MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit fix: kernel/fork.c:843: error: ‘struct signal_struct’ has no member named ‘sum_sched_runtime’ kernel/irq/handle.c:117: warning: ‘sparse_irq_lock’ defined but not used Signed-off-by: Ingo Molnar --- kernel/fork.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index a8ac2ef..1181b9a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -834,7 +834,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; task_io_accounting_init(&sig->ioac); - sig->sum_sched_runtime = 0; INIT_LIST_HEAD(&sig->cpu_timers[0]); INIT_LIST_HEAD(&sig->cpu_timers[1]); INIT_LIST_HEAD(&sig->cpu_timers[2]); -- cgit v1.1 From 5ce73a4a5a4893a1aa4cdeed1b1a5a6de42c43b6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 14 Sep 2008 17:11:46 +0200 Subject: timers: fix itimer/many thread hang, cleanups Signed-off-by: Ingo Molnar --- kernel/posix-cpu-timers.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index dba1c33..9a7ea04 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -94,7 +94,7 @@ void update_rlimit_cpu(unsigned long rlim_new) cputime = secs_to_cputime(rlim_new); if (cputime_eq(current->signal->it_prof_expires, cputime_zero) || - cputime_lt(current->signal->it_prof_expires, cputime)) { + cputime_lt(current->signal->it_prof_expires, cputime)) { spin_lock_irq(¤t->sighand->siglock); set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); spin_unlock_irq(¤t->sighand->siglock); @@ -1372,9 +1372,9 @@ void run_posix_cpu_timers(struct task_struct *tsk) * tsk->signal is non-NULL; this probably can't happen but cover the * possibility anyway. */ - if (unlikely(!sig) || !fastpath_timer_check(tsk, sig)) { + if (unlikely(!sig) || !fastpath_timer_check(tsk, sig)) return; - } + sighand = lock_task_sighand(tsk, &flags); if (likely(sighand)) { /* -- cgit v1.1 From d7cfb60c5cf904ecf1e0ae23ec178175b86f0d4a Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Fri, 19 Sep 2008 13:13:44 +0100 Subject: hrtimer: remove hrtimer_clock_base::get_softirq_time() Peter Zijlstra noticed this 8 months ago and I just noticed it again. hrtimer_clock_base::get_softirq_time() is currently unused in the entire tree. In fact, looking at the logs, it appears as if it was never used. Remove it. Signed-off-by: Mark McLoughlin Signed-off-by: Ingo Molnar --- kernel/hrtimer.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 03ea137..4d761d5 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1401,9 +1401,7 @@ void hrtimer_run_queues(void) if (!base->first) continue; - if (base->get_softirq_time) - base->softirq_time = base->get_softirq_time(); - else if (gettime) { + if (gettime) { hrtimer_get_softirq_time(cpu_base); gettime = 0; } -- cgit v1.1 From bb34d92f643086d546b49cef680f6f305ed84414 Mon Sep 17 00:00:00 2001 From: Frank Mayhar Date: Fri, 12 Sep 2008 09:54:39 -0700 Subject: timers: fix itimer/many thread hang, v2 This is the second resubmission of the posix timer rework patch, posted a few days ago. This includes the changes from the previous resubmittion, which addressed Oleg Nesterov's comments, removing the RCU stuff from the patch and un-inlining the thread_group_cputime() function for SMP. In addition, per Ingo Molnar it simplifies the UP code, consolidating much of it with the SMP version and depending on lower-level SMP/UP handling to take care of the differences. It also cleans up some UP compile errors, moves the scheduler stats-related macros into kernel/sched_stats.h, cleans up a merge error in kernel/fork.c and has a few other minor fixes and cleanups as suggested by Oleg and Ingo. Thanks for the review, guys. Signed-off-by: Frank Mayhar Cc: Roland McGrath Cc: Alexey Dobriyan Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/fork.c | 5 +- kernel/posix-cpu-timers.c | 153 +++++++++++++++++++--------------------------- kernel/sched.c | 47 +++----------- kernel/sched_stats.h | 136 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 208 insertions(+), 133 deletions(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 1181b9a..021ae01 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -791,7 +791,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) int ret; if (clone_flags & CLONE_THREAD) { - ret = thread_group_cputime_clone_thread(current, tsk); + ret = thread_group_cputime_clone_thread(current); if (likely(!ret)) { atomic_inc(¤t->signal->count); atomic_inc(¤t->signal->live); @@ -834,9 +834,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; task_io_accounting_init(&sig->ioac); - INIT_LIST_HEAD(&sig->cpu_timers[0]); - INIT_LIST_HEAD(&sig->cpu_timers[1]); - INIT_LIST_HEAD(&sig->cpu_timers[2]); taskstats_tgid_init(sig); task_lock(current->group_leader); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 9a7ea04..153dcb2 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -7,50 +7,46 @@ #include #include #include +#include -#ifdef CONFIG_SMP /* - * Allocate the thread_group_cputime structure appropriately for SMP kernels - * and fill in the current values of the fields. Called from copy_signal() - * via thread_group_cputime_clone_thread() when adding a second or subsequent + * Allocate the thread_group_cputime structure appropriately and fill in the + * current values of the fields. Called from copy_signal() via + * thread_group_cputime_clone_thread() when adding a second or subsequent * thread to a thread group. Assumes interrupts are enabled when called. */ -int thread_group_cputime_alloc_smp(struct task_struct *tsk) +int thread_group_cputime_alloc(struct task_struct *tsk) { struct signal_struct *sig = tsk->signal; struct task_cputime *cputime; /* * If we have multiple threads and we don't already have a - * per-CPU task_cputime struct, allocate one and fill it in with - * the times accumulated so far. + * per-CPU task_cputime struct (checked in the caller), allocate + * one and fill it in with the times accumulated so far. We may + * race with another thread so recheck after we pick up the sighand + * lock. */ - if (sig->cputime.totals) - return 0; cputime = alloc_percpu(struct task_cputime); if (cputime == NULL) return -ENOMEM; - read_lock(&tasklist_lock); spin_lock_irq(&tsk->sighand->siglock); if (sig->cputime.totals) { spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); free_percpu(cputime); return 0; } sig->cputime.totals = cputime; - cputime = per_cpu_ptr(sig->cputime.totals, get_cpu()); + cputime = per_cpu_ptr(sig->cputime.totals, smp_processor_id()); cputime->utime = tsk->utime; cputime->stime = tsk->stime; cputime->sum_exec_runtime = tsk->se.sum_exec_runtime; - put_cpu_no_resched(); spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); return 0; } /** - * thread_group_cputime_smp - Sum the thread group time fields across all CPUs. + * thread_group_cputime - Sum the thread group time fields across all CPUs. * * @tsk: The task we use to identify the thread group. * @times: task_cputime structure in which we return the summed fields. @@ -58,7 +54,7 @@ int thread_group_cputime_alloc_smp(struct task_struct *tsk) * Walk the list of CPUs to sum the per-CPU time fields in the thread group * time structure. */ -void thread_group_cputime_smp( +void thread_group_cputime( struct task_struct *tsk, struct task_cputime *times) { @@ -83,8 +79,6 @@ void thread_group_cputime_smp( } } -#endif /* CONFIG_SMP */ - /* * Called after updating RLIMIT_CPU to set timer expiration if necessary. */ @@ -300,7 +294,7 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, cpu->cpu = virt_ticks(p); break; case CPUCLOCK_SCHED: - cpu->sched = task_sched_runtime(p); + cpu->sched = p->se.sum_exec_runtime + task_delta_exec(p); break; } return 0; @@ -309,16 +303,15 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, /* * Sample a process (thread group) clock for the given group_leader task. * Must be called with tasklist_lock held for reading. - * Must be called with tasklist_lock held for reading, and p->sighand->siglock. */ -static int cpu_clock_sample_group_locked(unsigned int clock_idx, - struct task_struct *p, - union cpu_time_count *cpu) +static int cpu_clock_sample_group(const clockid_t which_clock, + struct task_struct *p, + union cpu_time_count *cpu) { struct task_cputime cputime; thread_group_cputime(p, &cputime); - switch (clock_idx) { + switch (which_clock) { default: return -EINVAL; case CPUCLOCK_PROF: @@ -328,29 +321,12 @@ static int cpu_clock_sample_group_locked(unsigned int clock_idx, cpu->cpu = cputime.utime; break; case CPUCLOCK_SCHED: - cpu->sched = thread_group_sched_runtime(p); + cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p); break; } return 0; } -/* - * Sample a process (thread group) clock for the given group_leader task. - * Must be called with tasklist_lock held for reading. - */ -static int cpu_clock_sample_group(const clockid_t which_clock, - struct task_struct *p, - union cpu_time_count *cpu) -{ - int ret; - unsigned long flags; - spin_lock_irqsave(&p->sighand->siglock, flags); - ret = cpu_clock_sample_group_locked(CPUCLOCK_WHICH(which_clock), p, - cpu); - spin_unlock_irqrestore(&p->sighand->siglock, flags); - return ret; -} - int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) { @@ -1324,29 +1300,37 @@ static inline int task_cputime_expired(const struct task_cputime *sample, * fastpath_timer_check - POSIX CPU timers fast path. * * @tsk: The task (thread) being checked. - * @sig: The signal pointer for that task. * - * If there are no timers set return false. Otherwise snapshot the task and - * thread group timers, then compare them with the corresponding expiration - # times. Returns true if a timer has expired, else returns false. + * Check the task and thread group timers. If both are zero (there are no + * timers set) return false. Otherwise snapshot the task and thread group + * timers and compare them with the corresponding expiration times. Return + * true if a timer has expired, else return false. */ -static inline int fastpath_timer_check(struct task_struct *tsk, - struct signal_struct *sig) +static inline int fastpath_timer_check(struct task_struct *tsk) { - struct task_cputime task_sample = { - .utime = tsk->utime, - .stime = tsk->stime, - .sum_exec_runtime = tsk->se.sum_exec_runtime - }; - struct task_cputime group_sample; + struct signal_struct *sig = tsk->signal; - if (task_cputime_zero(&tsk->cputime_expires) && - task_cputime_zero(&sig->cputime_expires)) + if (unlikely(!sig)) return 0; - if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) - return 1; - thread_group_cputime(tsk, &group_sample); - return task_cputime_expired(&group_sample, &sig->cputime_expires); + + if (!task_cputime_zero(&tsk->cputime_expires)) { + struct task_cputime task_sample = { + .utime = tsk->utime, + .stime = tsk->stime, + .sum_exec_runtime = tsk->se.sum_exec_runtime + }; + + if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) + return 1; + } + if (!task_cputime_zero(&sig->cputime_expires)) { + struct task_cputime group_sample; + + thread_group_cputime(tsk, &group_sample); + if (task_cputime_expired(&group_sample, &sig->cputime_expires)) + return 1; + } + return 0; } /* @@ -1358,43 +1342,34 @@ void run_posix_cpu_timers(struct task_struct *tsk) { LIST_HEAD(firing); struct k_itimer *timer, *next; - struct signal_struct *sig; - struct sighand_struct *sighand; - unsigned long flags; BUG_ON(!irqs_disabled()); - /* Pick up tsk->signal and make sure it's valid. */ - sig = tsk->signal; /* * The fast path checks that there are no expired thread or thread - * group timers. If that's so, just return. Also check that - * tsk->signal is non-NULL; this probably can't happen but cover the - * possibility anyway. + * group timers. If that's so, just return. */ - if (unlikely(!sig) || !fastpath_timer_check(tsk, sig)) + if (!fastpath_timer_check(tsk)) return; - sighand = lock_task_sighand(tsk, &flags); - if (likely(sighand)) { - /* - * Here we take off tsk->signal->cpu_timers[N] and - * tsk->cpu_timers[N] all the timers that are firing, and - * put them on the firing list. - */ - check_thread_timers(tsk, &firing); - check_process_timers(tsk, &firing); + spin_lock(&tsk->sighand->siglock); + /* + * Here we take off tsk->signal->cpu_timers[N] and + * tsk->cpu_timers[N] all the timers that are firing, and + * put them on the firing list. + */ + check_thread_timers(tsk, &firing); + check_process_timers(tsk, &firing); - /* - * We must release these locks before taking any timer's lock. - * There is a potential race with timer deletion here, as the - * siglock now protects our private firing list. We have set - * the firing flag in each timer, so that a deletion attempt - * that gets the timer lock before we do will give it up and - * spin until we've taken care of that timer below. - */ - } - unlock_task_sighand(tsk, &flags); + /* + * We must release these locks before taking any timer's lock. + * There is a potential race with timer deletion here, as the + * siglock now protects our private firing list. We have set + * the firing flag in each timer, so that a deletion attempt + * that gets the timer lock before we do will give it up and + * spin until we've taken care of that timer below. + */ + spin_unlock(&tsk->sighand->siglock); /* * Now that all the timers on our list have the firing flag, @@ -1433,7 +1408,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, struct list_head *head; BUG_ON(clock_idx == CPUCLOCK_SCHED); - cpu_clock_sample_group_locked(clock_idx, tsk, &now); + cpu_clock_sample_group(clock_idx, tsk, &now); if (oldval) { if (!cputime_eq(*oldval, cputime_zero)) { diff --git a/kernel/sched.c b/kernel/sched.c index c51b5d2..260c22c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4039,55 +4039,22 @@ EXPORT_PER_CPU_SYMBOL(kstat); /* * Return any ns on the sched_clock that have not yet been banked in * @p in case that task is currently running. - * - * Called with task_rq_lock() held on @rq. */ -static unsigned long long task_delta_exec(struct task_struct *p, struct rq *rq) +unsigned long long task_delta_exec(struct task_struct *p) { + struct rq *rq; + unsigned long flags; + u64 ns = 0; + + rq = task_rq_lock(p, &flags); if (task_current(rq, p)) { u64 delta_exec; update_rq_clock(rq); delta_exec = rq->clock - p->se.exec_start; if ((s64)delta_exec > 0) - return delta_exec; + ns = delta_exec; } - return 0; -} - -/* - * Return p->sum_exec_runtime plus any more ns on the sched_clock - * that have not yet been banked in case the task is currently running. - */ -unsigned long long task_sched_runtime(struct task_struct *p) -{ - unsigned long flags; - u64 ns; - struct rq *rq; - - rq = task_rq_lock(p, &flags); - ns = p->se.sum_exec_runtime + task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); - - return ns; -} - -/* - * Return sum_exec_runtime for the thread group plus any more ns on the - * sched_clock that have not yet been banked in case the task is currently - * running. - */ -unsigned long long thread_group_sched_runtime(struct task_struct *p) -{ - unsigned long flags; - u64 ns; - struct rq *rq; - struct task_cputime totals; - - rq = task_rq_lock(p, &flags); - thread_group_cputime(p, &totals); - ns = totals.sum_exec_runtime + task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); return ns; } diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 8385d43..d6903bd 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -270,3 +270,139 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next) #define sched_info_switch(t, next) do { } while (0) #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */ +/* + * The following are functions that support scheduler-internal time accounting. + * These functions are generally called at the timer tick. None of this depends + * on CONFIG_SCHEDSTATS. + */ + +#ifdef CONFIG_SMP + +/** + * thread_group_cputime_account_user - Maintain utime for a thread group. + * + * @tgtimes: Pointer to thread_group_cputime structure. + * @cputime: Time value by which to increment the utime field of that + * structure. + * + * If thread group time is being maintained, get the structure for the + * running CPU and update the utime field there. + */ +static inline void thread_group_cputime_account_user( + struct thread_group_cputime *tgtimes, + cputime_t cputime) +{ + if (tgtimes->totals) { + struct task_cputime *times; + + times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times->utime = cputime_add(times->utime, cputime); + put_cpu_no_resched(); + } +} + +/** + * thread_group_cputime_account_system - Maintain stime for a thread group. + * + * @tgtimes: Pointer to thread_group_cputime structure. + * @cputime: Time value by which to increment the stime field of that + * structure. + * + * If thread group time is being maintained, get the structure for the + * running CPU and update the stime field there. + */ +static inline void thread_group_cputime_account_system( + struct thread_group_cputime *tgtimes, + cputime_t cputime) +{ + if (tgtimes->totals) { + struct task_cputime *times; + + times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times->stime = cputime_add(times->stime, cputime); + put_cpu_no_resched(); + } +} + +/** + * thread_group_cputime_account_exec_runtime - Maintain exec runtime for a + * thread group. + * + * @tgtimes: Pointer to thread_group_cputime structure. + * @ns: Time value by which to increment the sum_exec_runtime field + * of that structure. + * + * If thread group time is being maintained, get the structure for the + * running CPU and update the sum_exec_runtime field there. + */ +static inline void thread_group_cputime_account_exec_runtime( + struct thread_group_cputime *tgtimes, + unsigned long long ns) +{ + if (tgtimes->totals) { + struct task_cputime *times; + + times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times->sum_exec_runtime += ns; + put_cpu_no_resched(); + } +} + +#else /* CONFIG_SMP */ + +static inline void thread_group_cputime_account_user( + struct thread_group_cputime *tgtimes, + cputime_t cputime) +{ + tgtimes->totals->utime = cputime_add(tgtimes->totals->utime, cputime); +} + +static inline void thread_group_cputime_account_system( + struct thread_group_cputime *tgtimes, + cputime_t cputime) +{ + tgtimes->totals->stime = cputime_add(tgtimes->totals->stime, cputime); +} + +static inline void thread_group_cputime_account_exec_runtime( + struct thread_group_cputime *tgtimes, + unsigned long long ns) +{ + tgtimes->totals->sum_exec_runtime += ns; +} + +#endif /* CONFIG_SMP */ + +/* + * These are the generic time-accounting routines that use the above + * functions. They are the functions actually called by the scheduler. + */ +static inline void account_group_user_time(struct task_struct *tsk, + cputime_t cputime) +{ + struct signal_struct *sig; + + sig = tsk->signal; + if (likely(sig)) + thread_group_cputime_account_user(&sig->cputime, cputime); +} + +static inline void account_group_system_time(struct task_struct *tsk, + cputime_t cputime) +{ + struct signal_struct *sig; + + sig = tsk->signal; + if (likely(sig)) + thread_group_cputime_account_system(&sig->cputime, cputime); +} + +static inline void account_group_exec_runtime(struct task_struct *tsk, + unsigned long long ns) +{ + struct signal_struct *sig; + + sig = tsk->signal; + if (likely(sig)) + thread_group_cputime_account_exec_runtime(&sig->cputime, ns); +} -- cgit v1.1 From 4aa7361179bed905fd0f35b236a5c65db683b9e0 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:46 -0700 Subject: posix-timers: don't switch to ->group_leader if ->it_process dies posix_timer_event() drops SIGEV_THREAD_ID and switches to ->group_leader if send_sigqueue() fails. This is not very useful and doesn't work reliably. send_sigqueue() can only fail if ->it_process is dead. But it can die before it dequeues the SI_TIMER signal, in that case the timer stops anyway. Remove this code. I guess it was needed a long ago to ensure that the timer is not destroyed when when its creator thread dies. Q: perhaps it makes sense to change sys_timer_settime() to return an error if ->it_process is dead? Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e36d579..3dfd15a 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -298,6 +298,7 @@ void do_schedule_next_timer(struct siginfo *info) int posix_timer_event(struct k_itimer *timr, int si_private) { + int shared, ret; /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->do_schedule_next_timer(). @@ -316,20 +317,10 @@ int posix_timer_event(struct k_itimer *timr, int si_private) timr->sigq->info.si_tid = timr->it_id; timr->sigq->info.si_value = timr->it_sigev_value; - if (timr->it_sigev_notify & SIGEV_THREAD_ID) { - struct task_struct *leader; - int ret = send_sigqueue(timr->sigq, timr->it_process, 0); - - if (likely(ret >= 0)) - return ret; - - timr->it_sigev_notify = SIGEV_SIGNAL; - leader = timr->it_process->group_leader; - put_task_struct(timr->it_process); - timr->it_process = leader; - } - - return send_sigqueue(timr->sigq, timr->it_process, 1); + shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); + ret = send_sigqueue(timr->sigq, timr->it_process, shared); + /* If we failed to send the signal the timer stops. */ + return ret > 0; } EXPORT_SYMBOL_GPL(posix_timer_event); -- cgit v1.1 From 918fc0372831dca73039e1577bfea0c2ce49bdb6 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:46 -0700 Subject: posix-timers: always do get_task_struct(timer->it_process) Change the code to get/put timer->it_process regardless of SIGEV_THREAD_ID. This streamlines the create/destroy paths and allows us to simplify the usage of exit_itimers() in de_thread(). Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 3dfd15a..bd9c931 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -540,11 +540,10 @@ sys_timer_create(const clockid_t which_clock, */ spin_lock_irqsave(&process->sighand->siglock, flags); if (!(process->flags & PF_EXITING)) { + get_task_struct(process); new_timer->it_process = process; list_add(&new_timer->list, &process->signal->posix_timers); - if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - get_task_struct(process); spin_unlock_irqrestore(&process->sighand->siglock, flags); } else { spin_unlock_irqrestore(&process->sighand->siglock, flags); @@ -561,6 +560,7 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_sigev_signo = SIGALRM; new_timer->it_sigev_value.sival_int = new_timer->it_id; process = current->group_leader; + get_task_struct(process); spin_lock_irqsave(&process->sighand->siglock, flags); new_timer->it_process = process; list_add(&new_timer->list, &process->signal->posix_timers); @@ -853,8 +853,7 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); + put_task_struct(timer->it_process); timer->it_process = NULL; unlock_timer(timer, flags); @@ -881,8 +880,7 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); + put_task_struct(timer->it_process); timer->it_process = NULL; unlock_timer(timer, flags); -- cgit v1.1 From 2cd499e38ec241691e4bce50bddc8f57e4cc9bd0 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:47 -0700 Subject: posix-timers: sys_timer_create: remove the buggy PF_EXITING check sys_timer_create() return -EINVAL if the target thread has PF_EXITING. This doesn't really make sense, the sub-thread can die right after unlock. And in fact, this is just wrong. Without SIGEV_THREAD_ID good_sigevent() returns ->group_leader, and it is very possible that the leader is already dead. This is OK, we shouldn't return the error in this case. Remove this check and the comment. Note that the "process" was found under tasklist_lock, it must have ->sighand != NULL. Also, remove a couple of unneeded initializations. Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 34 +++++++--------------------------- 1 file changed, 7 insertions(+), 27 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index bd9c931..60b2620 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -460,9 +460,9 @@ sys_timer_create(const clockid_t which_clock, timer_t __user * created_timer_id) { int error = 0; - struct k_itimer *new_timer = NULL; + struct k_itimer *new_timer; int new_timer_id; - struct task_struct *process = NULL; + struct task_struct *process; unsigned long flags; sigevent_t event; int it_id_set = IT_ID_NOT_SET; @@ -523,32 +523,12 @@ sys_timer_create(const clockid_t which_clock, read_lock(&tasklist_lock); if ((process = good_sigevent(&event))) { - /* - * We may be setting up this process for another - * thread. It may be exiting. To catch this - * case the we check the PF_EXITING flag. If - * the flag is not set, the siglock will catch - * him before it is too late (in exit_itimers). - * - * The exec case is a bit more invloved but easy - * to code. If the process is in our thread - * group (and it must be or we would not allow - * it here) and is doing an exec, it will cause - * us to be killed. In this case it will wait - * for us to die which means we can finish this - * linkage with our last gasp. I.e. no code :) - */ + get_task_struct(process); spin_lock_irqsave(&process->sighand->siglock, flags); - if (!(process->flags & PF_EXITING)) { - get_task_struct(process); - new_timer->it_process = process; - list_add(&new_timer->list, - &process->signal->posix_timers); - spin_unlock_irqrestore(&process->sighand->siglock, flags); - } else { - spin_unlock_irqrestore(&process->sighand->siglock, flags); - process = NULL; - } + new_timer->it_process = process; + list_add(&new_timer->list, + &process->signal->posix_timers); + spin_unlock_irqrestore(&process->sighand->siglock, flags); } read_unlock(&tasklist_lock); if (!process) { -- cgit v1.1 From 36b2f046000b358b62b9d116cb10a2b1c5be5cbf Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:48 -0700 Subject: posix-timers: sys_timer_create: simplify and s/tasklist/rcu/ - Change the code to do rcu_read_lock() instead of taking tasklist_lock, it is safe to get_task_struct(p) if p was found under RCU. However, now we must not use process's sighand/signal, they may be NULL. We can use current->sighand/signal instead, this "process" must belong to the current's thread-group. - Factor out the common code for 2 "if (timer_event_spec)" branches, the !timer_event_spec case can use current too. - use spin_lock_irq() instead of _irqsave(), kill "flags". Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 60b2620..5b76190 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -463,7 +463,6 @@ sys_timer_create(const clockid_t which_clock, struct k_itimer *new_timer; int new_timer_id; struct task_struct *process; - unsigned long flags; sigevent_t event; int it_id_set = IT_ID_NOT_SET; @@ -521,16 +520,11 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_sigev_signo = event.sigev_signo; new_timer->it_sigev_value = event.sigev_value; - read_lock(&tasklist_lock); - if ((process = good_sigevent(&event))) { + rcu_read_lock(); + process = good_sigevent(&event); + if (process) get_task_struct(process); - spin_lock_irqsave(&process->sighand->siglock, flags); - new_timer->it_process = process; - list_add(&new_timer->list, - &process->signal->posix_timers); - spin_unlock_irqrestore(&process->sighand->siglock, flags); - } - read_unlock(&tasklist_lock); + rcu_read_unlock(); if (!process) { error = -EINVAL; goto out; @@ -541,19 +535,18 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_sigev_value.sival_int = new_timer->it_id; process = current->group_leader; get_task_struct(process); - spin_lock_irqsave(&process->sighand->siglock, flags); - new_timer->it_process = process; - list_add(&new_timer->list, &process->signal->posix_timers); - spin_unlock_irqrestore(&process->sighand->siglock, flags); } + spin_lock_irq(¤t->sighand->siglock); + new_timer->it_process = process; + list_add(&new_timer->list, ¤t->signal->posix_timers); + spin_unlock_irq(¤t->sighand->siglock); /* * In the case of the timer belonging to another task, after * the task is unlocked, the timer is owned by the other task * and may cease to exist at any time. Don't use or modify * new_timer after the unlock call. */ - out: if (error) release_posix_timer(new_timer, it_id_set); -- cgit v1.1 From 717835d94d3e3d343a302df0a3cb9405887c3e2a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:49 -0700 Subject: posix-timers: move the initialization of timer->sigq from send to create path posix_timer_event() always populates timer->sigq with the same numbers, move this code into sys_timer_create(). Note that with this patch we can kill it_sigev_signo and it_sigev_value. Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 5b76190..c459b29 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -312,11 +312,6 @@ int posix_timer_event(struct k_itimer *timr, int si_private) */ timr->sigq->info.si_sys_private = si_private; - timr->sigq->info.si_signo = timr->it_sigev_signo; - timr->sigq->info.si_code = SI_TIMER; - timr->sigq->info.si_tid = timr->it_id; - timr->sigq->info.si_value = timr->it_sigev_value; - shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); ret = send_sigqueue(timr->sigq, timr->it_process, shared); /* If we failed to send the signal the timer stops. */ @@ -537,6 +532,11 @@ sys_timer_create(const clockid_t which_clock, get_task_struct(process); } + new_timer->sigq->info.si_code = SI_TIMER; + new_timer->sigq->info.si_tid = new_timer->it_id; + new_timer->sigq->info.si_signo = new_timer->it_sigev_signo; + new_timer->sigq->info.si_value = new_timer->it_sigev_value; + spin_lock_irq(¤t->sighand->siglock); new_timer->it_process = process; list_add(&new_timer->list, ¤t->signal->posix_timers); -- cgit v1.1 From ef864c958801768fb28bd3603cd0b098b394671c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:49 -0700 Subject: posix-timers: sys_timer_create: cleanup the error handling Cleanup. - sys_timer_create() is big and complicated. The code above the "out:" label relies on the fact that "error" must be == 0. This is not very robust, make the code more explicit. Remove the unneeded initialization of error. - If idr_get_new() succeeds (as it normally should), we check the returned value twice. Move the "-EAGAIN" check under "if (error)". Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index c459b29..7be385f 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -454,9 +454,8 @@ sys_timer_create(const clockid_t which_clock, struct sigevent __user *timer_event_spec, timer_t __user * created_timer_id) { - int error = 0; struct k_itimer *new_timer; - int new_timer_id; + int error, new_timer_id; struct task_struct *process; sigevent_t event; int it_id_set = IT_ID_NOT_SET; @@ -478,9 +477,9 @@ sys_timer_create(const clockid_t which_clock, error = idr_get_new(&posix_timers_id, (void *) new_timer, &new_timer_id); spin_unlock_irq(&idr_lock); - if (error == -EAGAIN) - goto retry; - else if (error) { + if (error) { + if (error == -EAGAIN) + goto retry; /* * Weird looking, but we return EAGAIN if the IDR is * full (proper POSIX return value for this) @@ -541,6 +540,8 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_process = process; list_add(&new_timer->list, ¤t->signal->posix_timers); spin_unlock_irq(¤t->sighand->siglock); + + return 0; /* * In the case of the timer belonging to another task, after * the task is unlocked, the timer is owned by the other task @@ -548,9 +549,7 @@ sys_timer_create(const clockid_t which_clock, * new_timer after the unlock call. */ out: - if (error) - release_posix_timer(new_timer, it_id_set); - + release_posix_timer(new_timer, it_id_set); return error; } -- cgit v1.1 From 5a9fa73072854981a5c05eb7ba18a96d49c2804f Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:50 -0700 Subject: posix-timers: kill ->it_sigev_signo and ->it_sigev_value With the recent changes ->it_sigev_signo and ->it_sigev_value are only used in sys_timer_create(), kill them. Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 7be385f..3eff47b 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -510,10 +510,6 @@ sys_timer_create(const clockid_t which_clock, error = -EFAULT; goto out; } - new_timer->it_sigev_notify = event.sigev_notify; - new_timer->it_sigev_signo = event.sigev_signo; - new_timer->it_sigev_value = event.sigev_value; - rcu_read_lock(); process = good_sigevent(&event); if (process) @@ -524,17 +520,18 @@ sys_timer_create(const clockid_t which_clock, goto out; } } else { - new_timer->it_sigev_notify = SIGEV_SIGNAL; - new_timer->it_sigev_signo = SIGALRM; - new_timer->it_sigev_value.sival_int = new_timer->it_id; + event.sigev_notify = SIGEV_SIGNAL; + event.sigev_signo = SIGALRM; + event.sigev_value.sival_int = new_timer->it_id; process = current->group_leader; get_task_struct(process); } - new_timer->sigq->info.si_code = SI_TIMER; + new_timer->it_sigev_notify = event.sigev_notify; + new_timer->sigq->info.si_signo = event.sigev_signo; + new_timer->sigq->info.si_value = event.sigev_value; new_timer->sigq->info.si_tid = new_timer->it_id; - new_timer->sigq->info.si_signo = new_timer->it_sigev_signo; - new_timer->sigq->info.si_value = new_timer->it_sigev_value; + new_timer->sigq->info.si_code = SI_TIMER; spin_lock_irq(¤t->sighand->siglock); new_timer->it_process = process; -- cgit v1.1 From 5a51b713ccf8835d5adf7217e2f86eb12b1ca851 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:51 -0700 Subject: posix-timers: lock_timer: kill the bogus ->it_id check lock_timer() checks that the timer found by idr_find(timer_id) has ->it_id == timer_id. This buys nothing. This check can fail only if sys_timer_create() unlocked idr_lock after idr_get_new(), but didn't set ->it_id = new_timer_id yet. But in that case ->it_process == NULL so lock_timer() can't succeed anyway. Also remove a couple of unneeded typecasts. Note that with or without this patch we have a small problem. sys_timer_create() doesn't ensure that the result of setting (say) ->it_sigev_notify must be visible if lock_timer() succeeds. Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 3eff47b..7185f05 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -474,8 +474,7 @@ sys_timer_create(const clockid_t which_clock, goto out; } spin_lock_irq(&idr_lock); - error = idr_get_new(&posix_timers_id, (void *) new_timer, - &new_timer_id); + error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id); spin_unlock_irq(&idr_lock); if (error) { if (error == -EAGAIN) @@ -567,12 +566,12 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) */ spin_lock_irqsave(&idr_lock, *flags); - timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); + timr = idr_find(&posix_timers_id, (int) timer_id); if (timr) { spin_lock(&timr->it_lock); - if ((timr->it_id != timer_id) || !(timr->it_process) || - !same_thread_group(timr->it_process, current)) { + if (!timr->it_process || + !same_thread_group(timr->it_process, current)) { spin_unlock(&timr->it_lock); spin_unlock_irqrestore(&idr_lock, *flags); timr = NULL; -- cgit v1.1 From 31d9284569e38fb97117497af3e8047a6a3c86f0 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 22 Sep 2008 14:42:51 -0700 Subject: posix-timers: lock_timer: make it readable Cleanup. Imho makes the code much more understandable. At least this patch lessens both the source and compiled code. Signed-off-by: Oleg Nesterov Cc: mingo@elte.hu Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 7185f05..95451bf 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -556,7 +556,7 @@ out: * the find to the timer lock. To avoid a dead lock, the timer id MUST * be release with out holding the timer lock. */ -static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) +static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; /* @@ -564,23 +564,20 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) * flags part over to the timer lock. Must not let interrupts in * while we are moving the lock. */ - spin_lock_irqsave(&idr_lock, *flags); - timr = idr_find(&posix_timers_id, (int) timer_id); + timr = idr_find(&posix_timers_id, (int)timer_id); if (timr) { spin_lock(&timr->it_lock); - - if (!timr->it_process || - !same_thread_group(timr->it_process, current)) { - spin_unlock(&timr->it_lock); - spin_unlock_irqrestore(&idr_lock, *flags); - timr = NULL; - } else + if (timr->it_process && + same_thread_group(timr->it_process, current)) { spin_unlock(&idr_lock); - } else - spin_unlock_irqrestore(&idr_lock, *flags); + return timr; + } + spin_unlock(&timr->it_lock); + } + spin_unlock_irqrestore(&idr_lock, *flags); - return timr; + return NULL; } /* -- cgit v1.1 From eb3f938fd6292dc79f43a5fe14784b044776e9f0 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Mon, 22 Sep 2008 14:42:40 -0700 Subject: ntp: let update_persistent_clock() sleep This is a change that makes the 11-minute RTC update be run in the process context. This is so that update_persistent_clock() can sleep, which may be required for certain types of RTC hardware -- most notably I2C devices. Signed-off-by: Maciej W. Rozycki Cc: Roman Zippel Cc: Rik van Riel Cc: David Brownell Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/time/ntp.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index c6921aa1..450a45c 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -10,13 +10,13 @@ #include #include -#include #include #include #include #include #include #include +#include #include /* @@ -218,11 +218,11 @@ void second_overflow(void) /* Disable the cmos update - used by virtualization and embedded */ int no_sync_cmos_clock __read_mostly; -static void sync_cmos_clock(unsigned long dummy); +static void sync_cmos_clock(struct work_struct *work); -static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0); +static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); -static void sync_cmos_clock(unsigned long dummy) +static void sync_cmos_clock(struct work_struct *work) { struct timespec now, next; int fail = 1; @@ -258,13 +258,13 @@ static void sync_cmos_clock(unsigned long dummy) next.tv_sec++; next.tv_nsec -= NSEC_PER_SEC; } - mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next)); + schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next)); } static void notify_cmos_timer(void) { if (!no_sync_cmos_clock) - mod_timer(&sync_cmos_timer, jiffies + 1); + schedule_delayed_work(&sync_cmos_work, 0); } #else -- cgit v1.1 From 5cd1c9c5cf30d4b33df3d3f74d8142f278d536b7 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Mon, 22 Sep 2008 14:42:43 -0700 Subject: timekeeping: fix rounding problem during clock update Due to a rounding problem during a clock update it's possible for readers to observe the clock jumping back by 1nsec. The following simplified example demonstrates the problem: cycle xtime 0 0 1000 999999.6 2000 1999999.2 3000 2999998.8 ... 1500 = 1499999.4 = 0.0 + 1499999.4 = 999999.6 + 499999.8 When reading the clock only the full nanosecond part is used, while timekeeping internally keeps nanosecond fractions. If the clock is now updated at cycle 1500 here, a nanosecond is missing due to the truncation. The simple fix is to round up the xtime value during the update, this also changes the distance to the reference time, but the adjustment will automatically take care that it stays under control. Signed-off-by: Roman Zippel Signed-off-by: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e91c29f..5ecbfc3 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -454,7 +454,7 @@ void update_wall_time(void) #else offset = clock->cycle_interval; #endif - clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift; + clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift; /* normally this loop will run just once, however in the * case of lost or late ticks, it will accumulate correctly. @@ -479,9 +479,12 @@ void update_wall_time(void) /* correct the clock when NTP error is too big */ clocksource_adjust(offset); - /* store full nanoseconds into xtime */ - xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift; + /* store full nanoseconds into xtime after rounding it up and + * add the remainder to the error difference. + */ + xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1; clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; + clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift); update_xtime_cache(cyc2ns(clock, offset)); -- cgit v1.1 From d40e944c25fb4642adb2a4c580a48218a9f3f824 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Mon, 22 Sep 2008 14:42:44 -0700 Subject: ntp: improve adjtimex frequency rounding Change PPM_SCALE_INV_SHIFT so that it doesn't throw away any input bits (19 is the amount of the factor 2 in PPM_SCALE), the output frequency can then be calculated back to its input value, as the inverse divide produce a slightly larger value, which is then correctly rounded by the final shift. Reported-by: Martin Ziegler Signed-off-by: Roman Zippel Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/time/ntp.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 450a45c..ddb0465 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -406,9 +406,8 @@ adj_done: if (time_status & (STA_UNSYNC|STA_CLOCKERR)) result = TIME_ERROR; - txc->freq = shift_right((s32)(time_freq >> PPM_SCALE_INV_SHIFT) * - (s64)PPM_SCALE_INV, - NTP_SCALE_SHIFT); + txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) * + (s64)PPM_SCALE_INV, NTP_SCALE_SHIFT); txc->maxerror = time_maxerror; txc->esterror = time_esterror; txc->status = time_status; -- cgit v1.1 From 7086efe1c1536f6bc160e7d60a9bfd645b91f279 Mon Sep 17 00:00:00 2001 From: Frank Mayhar Date: Fri, 12 Sep 2008 09:54:39 -0700 Subject: timers: fix itimer/many thread hang, v3 - fix UP lockup - another set of UP/SMP cleanups and simplifications Signed-off-by: Frank Mayhar Signed-off-by: Ingo Molnar --- kernel/sched.c | 1 - kernel/sched_stats.h | 126 ++++++++++++++++----------------------------------- 2 files changed, 38 insertions(+), 89 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 260c22c..29a3152 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4046,7 +4046,6 @@ unsigned long long task_delta_exec(struct task_struct *p) unsigned long flags; u64 ns = 0; - rq = task_rq_lock(p, &flags); if (task_current(rq, p)) { u64 delta_exec; diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index d6903bd..b8c1569 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -276,133 +276,83 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next) * on CONFIG_SCHEDSTATS. */ -#ifdef CONFIG_SMP - /** - * thread_group_cputime_account_user - Maintain utime for a thread group. + * account_group_user_time - Maintain utime for a thread group. * - * @tgtimes: Pointer to thread_group_cputime structure. - * @cputime: Time value by which to increment the utime field of that - * structure. + * @tsk: Pointer to task structure. + * @cputime: Time value by which to increment the utime field of the + * thread_group_cputime structure. * * If thread group time is being maintained, get the structure for the * running CPU and update the utime field there. */ -static inline void thread_group_cputime_account_user( - struct thread_group_cputime *tgtimes, - cputime_t cputime) +static inline void account_group_user_time(struct task_struct *tsk, + cputime_t cputime) { - if (tgtimes->totals) { + struct signal_struct *sig; + + sig = tsk->signal; + if (unlikely(!sig)) + return; + if (sig->cputime.totals) { struct task_cputime *times; - times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times = per_cpu_ptr(sig->cputime.totals, get_cpu()); times->utime = cputime_add(times->utime, cputime); put_cpu_no_resched(); } } /** - * thread_group_cputime_account_system - Maintain stime for a thread group. + * account_group_system_time - Maintain stime for a thread group. * - * @tgtimes: Pointer to thread_group_cputime structure. - * @cputime: Time value by which to increment the stime field of that - * structure. + * @tsk: Pointer to task structure. + * @cputime: Time value by which to increment the stime field of the + * thread_group_cputime structure. * * If thread group time is being maintained, get the structure for the * running CPU and update the stime field there. */ -static inline void thread_group_cputime_account_system( - struct thread_group_cputime *tgtimes, - cputime_t cputime) +static inline void account_group_system_time(struct task_struct *tsk, + cputime_t cputime) { - if (tgtimes->totals) { + struct signal_struct *sig; + + sig = tsk->signal; + if (unlikely(!sig)) + return; + if (sig->cputime.totals) { struct task_cputime *times; - times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times = per_cpu_ptr(sig->cputime.totals, get_cpu()); times->stime = cputime_add(times->stime, cputime); put_cpu_no_resched(); } } /** - * thread_group_cputime_account_exec_runtime - Maintain exec runtime for a - * thread group. + * account_group_exec_runtime - Maintain exec runtime for a thread group. * - * @tgtimes: Pointer to thread_group_cputime structure. + * @tsk: Pointer to task structure. * @ns: Time value by which to increment the sum_exec_runtime field - * of that structure. + * of the thread_group_cputime structure. * * If thread group time is being maintained, get the structure for the * running CPU and update the sum_exec_runtime field there. */ -static inline void thread_group_cputime_account_exec_runtime( - struct thread_group_cputime *tgtimes, - unsigned long long ns) +static inline void account_group_exec_runtime(struct task_struct *tsk, + unsigned long long ns) { - if (tgtimes->totals) { + struct signal_struct *sig; + + sig = tsk->signal; + if (unlikely(!sig)) + return; + if (sig->cputime.totals) { struct task_cputime *times; - times = per_cpu_ptr(tgtimes->totals, get_cpu()); + times = per_cpu_ptr(sig->cputime.totals, get_cpu()); times->sum_exec_runtime += ns; put_cpu_no_resched(); } } - -#else /* CONFIG_SMP */ - -static inline void thread_group_cputime_account_user( - struct thread_group_cputime *tgtimes, - cputime_t cputime) -{ - tgtimes->totals->utime = cputime_add(tgtimes->totals->utime, cputime); -} - -static inline void thread_group_cputime_account_system( - struct thread_group_cputime *tgtimes, - cputime_t cputime) -{ - tgtimes->totals->stime = cputime_add(tgtimes->totals->stime, cputime); -} - -static inline void thread_group_cputime_account_exec_runtime( - struct thread_group_cputime *tgtimes, - unsigned long long ns) -{ - tgtimes->totals->sum_exec_runtime += ns; -} - -#endif /* CONFIG_SMP */ - -/* - * These are the generic time-accounting routines that use the above - * functions. They are the functions actually called by the scheduler. - */ -static inline void account_group_user_time(struct task_struct *tsk, - cputime_t cputime) -{ - struct signal_struct *sig; - - sig = tsk->signal; - if (likely(sig)) - thread_group_cputime_account_user(&sig->cputime, cputime); -} - -static inline void account_group_system_time(struct task_struct *tsk, - cputime_t cputime) -{ - struct signal_struct *sig; - - sig = tsk->signal; - if (likely(sig)) - thread_group_cputime_account_system(&sig->cputime, cputime); -} - -static inline void account_group_exec_runtime(struct task_struct *tsk, - unsigned long long ns) -{ - struct signal_struct *sig; - - sig = tsk->signal; - if (likely(sig)) - thread_group_cputime_account_exec_runtime(&sig->cputime, ns); -} -- cgit v1.1 From 1508487e7f16d992ad23cabd3712563ff912f413 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 30 Sep 2008 08:28:17 +0200 Subject: timers: fix itimer/many thread hang, fix fix bogus rq dereference: v3 removed the locking but also removed the rq initialization. Signed-off-by: Ingo Molnar --- kernel/sched.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 29a3152..ebb03de 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4042,10 +4042,12 @@ EXPORT_PER_CPU_SYMBOL(kstat); */ unsigned long long task_delta_exec(struct task_struct *p) { - struct rq *rq; unsigned long flags; + struct rq *rq; u64 ns = 0; + rq = task_rq_lock(p, &flags); + if (task_current(rq, p)) { u64 delta_exec; @@ -4055,6 +4057,8 @@ unsigned long long task_delta_exec(struct task_struct *p) ns = delta_exec; } + task_rq_unlock(rq, &flags); + return ns; } -- cgit v1.1 From 0c5d1eb77a8be917b638344a22afe1398236482b Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 1 Oct 2008 14:46:18 -0700 Subject: genirq: record trigger type Genirq hasn't previously recorded the trigger type used by any given IRQ, although some irq_chip support has done so. That data can be useful when troubleshooting. This patch records it in the relevant irq_desc.status bits, and improves consistency between the two driver-visible calls affected: - Make set_irq_type() usage match request_irq() usage: * IRQ_TYPE_NONE should be a NOP; succeed, so irq_chip methods won't have to handle that case any more (many do it wrong). * IRQ_TYPE_PROBE is ignored; any buggy out-of-tree callers might need to switch over to the real IRQ probing code. * emit the same diagnostics (from shared utility code) - Their kerneldoc now reflects usage: * request_irq() flags include IRQF_TRIGGER_* to specify active edge(s)/level ... docs previously omitted that * set_irq_type() is declared in so callers should use the (bit-equivalent) IRQ_TYPE_* symbols there Also: adds a warning about shared IRQs that don't end up using the requested trigger mode; and fix an unrelated "sparse" warning. Signed-off-by: David Brownell Signed-off-by: Andrew Morton Acked-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 15 ++++++++------- kernel/irq/internals.h | 3 +++ kernel/irq/manage.c | 21 ++++++++++++++++++--- 3 files changed, 29 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index d663338..5203a59 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -111,9 +111,9 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) EXPORT_SYMBOL(set_irq_chip); /** - * set_irq_type - set the irq type for an irq + * set_irq_type - set the irq trigger type for an irq * @irq: irq number - * @type: interrupt type - see include/linux/interrupt.h + * @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h */ int set_irq_type(unsigned int irq, unsigned int type) { @@ -127,11 +127,12 @@ int set_irq_type(unsigned int irq, unsigned int type) } desc = irq_desc + irq; - if (desc->chip->set_type) { - spin_lock_irqsave(&desc->lock, flags); - ret = desc->chip->set_type(irq, type); - spin_unlock_irqrestore(&desc->lock, flags); - } + if (type == IRQ_TYPE_NONE) + return 0; + + spin_lock_irqsave(&desc->lock, flags); + ret = __irq_set_trigger(desc, irq, flags); + spin_unlock_irqrestore(&desc->lock, flags); return ret; } EXPORT_SYMBOL(set_irq_type); diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 08a849a..422dd00 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -10,6 +10,9 @@ extern void irq_chip_set_defaults(struct irq_chip *chip); /* Set default handler: */ extern void compat_irq_chip_set_default_handler(struct irq_desc *desc); +extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, + unsigned long flags); + #ifdef CONFIG_PROC_FS extern void register_irq_proc(unsigned int irq); extern void register_handler_proc(unsigned int irq, struct irqaction *action); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index d62f69b..e59157b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -216,7 +216,7 @@ void enable_irq(unsigned int irq) } EXPORT_SYMBOL(enable_irq); -int set_irq_wake_real(unsigned int irq, unsigned int on) +static int set_irq_wake_real(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_desc + irq; int ret = -ENXIO; @@ -305,10 +305,11 @@ void compat_irq_chip_set_default_handler(struct irq_desc *desc) desc->handle_irq = NULL; } -static int __irq_set_trigger(struct irq_chip *chip, unsigned int irq, +int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, unsigned long flags) { int ret; + struct irq_chip *chip = desc->chip; if (!chip || !chip->set_type) { /* @@ -326,6 +327,11 @@ static int __irq_set_trigger(struct irq_chip *chip, unsigned int irq, pr_err("setting trigger mode %d for irq %u failed (%pF)\n", (int)(flags & IRQF_TRIGGER_MASK), irq, chip->set_type); + else { + /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ + desc->status &= ~IRQ_TYPE_SENSE_MASK; + desc->status |= flags & IRQ_TYPE_SENSE_MASK; + } return ret; } @@ -404,7 +410,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) /* Setup the type (level, edge polarity) if configured: */ if (new->flags & IRQF_TRIGGER_MASK) { - ret = __irq_set_trigger(desc->chip, irq, new->flags); + ret = __irq_set_trigger(desc, irq, new->flags); if (ret) { spin_unlock_irqrestore(&desc->lock, flags); @@ -430,6 +436,14 @@ int setup_irq(unsigned int irq, struct irqaction *new) /* Set default affinity mask once everything is setup */ irq_select_affinity(irq); + + } else if ((new->flags & IRQF_TRIGGER_MASK) + && (new->flags & IRQF_TRIGGER_MASK) + != (desc->status & IRQ_TYPE_SENSE_MASK)) { + /* hope the handler works with the actual trigger mode... */ + pr_warning("IRQ %d uses trigger mode %d; requested %d\n", + irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), + (int)(new->flags & IRQF_TRIGGER_MASK)); } *p = new; @@ -586,6 +600,7 @@ EXPORT_SYMBOL(free_irq); * IRQF_SHARED Interrupt is shared * IRQF_DISABLED Disable local interrupts while processing * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy + * IRQF_TRIGGER_* Specify active edge(s) or level * */ int request_irq(unsigned int irq, irq_handler_t handler, -- cgit v1.1 From 030aebd2e439a2ebcca2b0ce30a02ed84feb043e Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sat, 11 Oct 2008 12:25:45 -0700 Subject: rangetimer: fix BUG_ON reported by Ingo There's a small race/chance that, while hrtimers are enabled globally, they're later not enabled when we're calling the hrtimer_interrupt() function, which then BUG_ON()'s for that. This patch closes that race/gap. Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index eb2cf98..b17657d 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1395,11 +1395,15 @@ void hrtimer_peek_ahead_timers(void) unsigned long flags; struct tick_device *td; struct clock_event_device *dev; - + struct hrtimer_cpu_base *cpu_base; if (hrtimer_hres_active()) return; local_irq_save(flags); + cpu_base = &__get_cpu_var(hrtimer_bases); + if (!cpu_base->hres_active) + goto out; + td = &__get_cpu_var(tick_cpu_device); if (!td) goto out; -- cgit v1.1 From dc4304f7deee29fcdf6a2b62f7146ea7f505fd42 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 13 Oct 2008 10:32:15 -0400 Subject: rangetimers: fix the bug reported by Ingo for real and please hand me a brown paper bag (thanks to Thomas for pointing out this very obvious bug) Signed-off-by: Arjan van de Ven --- kernel/hrtimer.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b17657d..2bd230b 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1395,15 +1395,11 @@ void hrtimer_peek_ahead_timers(void) unsigned long flags; struct tick_device *td; struct clock_event_device *dev; - struct hrtimer_cpu_base *cpu_base; - if (hrtimer_hres_active()) + + if (!hrtimer_hres_active()) return; local_irq_save(flags); - cpu_base = &__get_cpu_var(hrtimer_bases); - if (!cpu_base->hres_active) - goto out; - td = &__get_cpu_var(tick_cpu_device); if (!td) goto out; -- cgit v1.1 From 97e1c18e8d17bd87e1e383b2e9d9fc740332c8e2 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 18 Jul 2008 12:16:16 -0400 Subject: tracing: Kernel Tracepoints Implementation of kernel tracepoints. Inspired from the Linux Kernel Markers. Allows complete typing verification by declaring both tracing statement inline functions and probe registration/unregistration static inline functions within the same macro "DEFINE_TRACE". No format string is required. See the tracepoint Documentation and Samples patches for usage examples. Taken from the documentation patch : "A tracepoint placed in code provides a hook to call a function (probe) that you can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or "off" (no probe is attached). When a tracepoint is "off" it has no effect, except for adding a tiny time penalty (checking a condition for a branch) and space penalty (adding a few bytes for the function call at the end of the instrumented function and adds a data structure in a separate section). When a tracepoint is "on", the function you provide is called each time the tracepoint is executed, in the execution context of the caller. When the function provided ends its execution, it returns to the caller (continuing from the tracepoint site). You can put tracepoints at important locations in the code. They are lightweight hooks that can pass an arbitrary number of parameters, which prototypes are described in a tracepoint declaration placed in a header file." Addition and removal of tracepoints is synchronized by RCU using the scheduler (and preempt_disable) as guarantees to find a quiescent state (this is really RCU "classic"). The update side uses rcu_barrier_sched() with call_rcu_sched() and the read/execute side uses "preempt_disable()/preempt_enable()". We make sure the previous array containing probes, which has been scheduled for deletion by the rcu callback, is indeed freed before we proceed to the next update. It therefore limits the rate of modification of a single tracepoint to one update per RCU period. The objective here is to permit fast batch add/removal of probes on _different_ tracepoints. Changelog : - Use #name ":" #proto as string to identify the tracepoint in the tracepoint table. This will make sure not type mismatch happens due to connexion of a probe with the wrong type to a tracepoint declared with the same name in a different header. - Add tracepoint_entry_free_old. - Change __TO_TRACE to get rid of the 'i' iterator. Masami Hiramatsu : Tested on x86-64. Performance impact of a tracepoint : same as markers, except that it adds about 70 bytes of instructions in an unlikely branch of each instrumented function (the for loop, the stack setup and the function call). It currently adds a memory read, a test and a conditional branch at the instrumentation site (in the hot path). Immediate values will eventually change this into a load immediate, test and branch, which removes the memory read which will make the i-cache impact smaller (changing the memory read for a load immediate removes 3-4 bytes per site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it also saves the d-cache hit). About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. Quoting Hideo Aoki about Markers : I evaluated overhead of kernel marker using linux-2.6-sched-fixes git tree, which includes several markers for LTTng, using an ia64 server. While the immediate trace mark feature isn't implemented on ia64, there is no major performance regression. So, I think that we don't have any issues to propose merging marker point patches into Linus's tree from the viewpoint of performance impact. I prepared two kernels to evaluate. The first one was compiled without CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS. I downloaded the original hackbench from the following URL: http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c I ran hackbench 5 times in each condition and calculated the average and difference between the kernels. The parameter of hackbench: every 50 from 50 to 800 The number of CPUs of the server: 2, 4, and 8 Below is the results. As you can see, major performance regression wasn't found in any case. Even if number of processes increases, differences between marker-enabled kernel and marker- disabled kernel doesn't increase. Moreover, if number of CPUs increases, the differences doesn't increase either. Curiously, marker-enabled kernel is better than marker-disabled kernel in more than half cases, although I guess it comes from the difference of memory access pattern. * 2 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 4.811 | 4.872 | +0.061 | +1.27 | 100 | 9.854 | 10.309 | +0.454 | +4.61 | 150 | 15.602 | 15.040 | -0.562 | -3.6 | 200 | 20.489 | 20.380 | -0.109 | -0.53 | 250 | 25.798 | 25.652 | -0.146 | -0.56 | 300 | 31.260 | 30.797 | -0.463 | -1.48 | 350 | 36.121 | 35.770 | -0.351 | -0.97 | 400 | 42.288 | 42.102 | -0.186 | -0.44 | 450 | 47.778 | 47.253 | -0.526 | -1.1 | 500 | 51.953 | 52.278 | +0.325 | +0.63 | 550 | 58.401 | 57.700 | -0.701 | -1.2 | 600 | 63.334 | 63.222 | -0.112 | -0.18 | 650 | 68.816 | 68.511 | -0.306 | -0.44 | 700 | 74.667 | 74.088 | -0.579 | -0.78 | 750 | 78.612 | 79.582 | +0.970 | +1.23 | 800 | 85.431 | 85.263 | -0.168 | -0.2 | -------------------------------------------------------------- * 4 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.586 | 2.584 | -0.003 | -0.1 | 100 | 5.254 | 5.283 | +0.030 | +0.56 | 150 | 8.012 | 8.074 | +0.061 | +0.76 | 200 | 11.172 | 11.000 | -0.172 | -1.54 | 250 | 13.917 | 14.036 | +0.119 | +0.86 | 300 | 16.905 | 16.543 | -0.362 | -2.14 | 350 | 19.901 | 20.036 | +0.135 | +0.68 | 400 | 22.908 | 23.094 | +0.186 | +0.81 | 450 | 26.273 | 26.101 | -0.172 | -0.66 | 500 | 29.554 | 29.092 | -0.461 | -1.56 | 550 | 32.377 | 32.274 | -0.103 | -0.32 | 600 | 35.855 | 35.322 | -0.533 | -1.49 | 650 | 39.192 | 38.388 | -0.804 | -2.05 | 700 | 41.744 | 41.719 | -0.025 | -0.06 | 750 | 45.016 | 44.496 | -0.520 | -1.16 | 800 | 48.212 | 47.603 | -0.609 | -1.26 | -------------------------------------------------------------- * 8 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.094 | 2.072 | -0.022 | -1.07 | 100 | 4.162 | 4.273 | +0.111 | +2.66 | 150 | 6.485 | 6.540 | +0.055 | +0.84 | 200 | 8.556 | 8.478 | -0.078 | -0.91 | 250 | 10.458 | 10.258 | -0.200 | -1.91 | 300 | 12.425 | 12.750 | +0.325 | +2.62 | 350 | 14.807 | 14.839 | +0.032 | +0.22 | 400 | 16.801 | 16.959 | +0.158 | +0.94 | 450 | 19.478 | 19.009 | -0.470 | -2.41 | 500 | 21.296 | 21.504 | +0.208 | +0.98 | 550 | 23.842 | 23.979 | +0.137 | +0.57 | 600 | 26.309 | 26.111 | -0.198 | -0.75 | 650 | 28.705 | 28.446 | -0.259 | -0.9 | 700 | 31.233 | 31.394 | +0.161 | +0.52 | 750 | 34.064 | 33.720 | -0.344 | -1.01 | 800 | 36.320 | 36.114 | -0.206 | -0.57 | -------------------------------------------------------------- Signed-off-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu Acked-by: 'Peter Zijlstra' Signed-off-by: Ingo Molnar --- kernel/Makefile | 1 + kernel/module.c | 66 +++++++- kernel/tracepoint.c | 476 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 542 insertions(+), 1 deletion(-) create mode 100644 kernel/tracepoint.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 4e1d7df..8f9ce7e 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -83,6 +83,7 @@ obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_MARKERS) += marker.o +obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o obj-$(CONFIG_FTRACE) += trace/ diff --git a/kernel/module.c b/kernel/module.c index 9db1191..661d73d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -46,6 +46,7 @@ #include #include #include +#include #if 0 #define DEBUGP printk @@ -1831,6 +1832,8 @@ static noinline struct module *load_module(void __user *umod, #endif unsigned int markersindex; unsigned int markersstringsindex; + unsigned int tracepointsindex; + unsigned int tracepointsstringsindex; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ @@ -2117,6 +2120,9 @@ static noinline struct module *load_module(void __user *umod, markersindex = find_sec(hdr, sechdrs, secstrings, "__markers"); markersstringsindex = find_sec(hdr, sechdrs, secstrings, "__markers_strings"); + tracepointsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints"); + tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings, + "__tracepoints_strings"); /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { @@ -2144,6 +2150,12 @@ static noinline struct module *load_module(void __user *umod, mod->num_markers = sechdrs[markersindex].sh_size / sizeof(*mod->markers); #endif +#ifdef CONFIG_TRACEPOINTS + mod->tracepoints = (void *)sechdrs[tracepointsindex].sh_addr; + mod->num_tracepoints = + sechdrs[tracepointsindex].sh_size / sizeof(*mod->tracepoints); +#endif + /* Find duplicate symbols */ err = verify_export_symbols(mod); @@ -2162,11 +2174,16 @@ static noinline struct module *load_module(void __user *umod, add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); + if (!mod->taints) { #ifdef CONFIG_MARKERS - if (!mod->taints) marker_update_probe_range(mod->markers, mod->markers + mod->num_markers); #endif +#ifdef CONFIG_TRACEPOINTS + tracepoint_update_probe_range(mod->tracepoints, + mod->tracepoints + mod->num_tracepoints); +#endif + } err = module_finalize(hdr, sechdrs, mod); if (err < 0) goto cleanup; @@ -2717,3 +2734,50 @@ void module_update_markers(void) mutex_unlock(&module_mutex); } #endif + +#ifdef CONFIG_TRACEPOINTS +void module_update_tracepoints(void) +{ + struct module *mod; + + mutex_lock(&module_mutex); + list_for_each_entry(mod, &modules, list) + if (!mod->taints) + tracepoint_update_probe_range(mod->tracepoints, + mod->tracepoints + mod->num_tracepoints); + mutex_unlock(&module_mutex); +} + +/* + * Returns 0 if current not found. + * Returns 1 if current found. + */ +int module_get_iter_tracepoints(struct tracepoint_iter *iter) +{ + struct module *iter_mod; + int found = 0; + + mutex_lock(&module_mutex); + list_for_each_entry(iter_mod, &modules, list) { + if (!iter_mod->taints) { + /* + * Sorted module list + */ + if (iter_mod < iter->module) + continue; + else if (iter_mod > iter->module) + iter->tracepoint = NULL; + found = tracepoint_get_iter_range(&iter->tracepoint, + iter_mod->tracepoints, + iter_mod->tracepoints + + iter_mod->num_tracepoints); + if (found) { + iter->module = iter_mod; + break; + } + } + } + mutex_unlock(&module_mutex); + return found; +} +#endif diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c new file mode 100644 index 0000000..42e86dd --- /dev/null +++ b/kernel/tracepoint.c @@ -0,0 +1,476 @@ +/* + * Copyright (C) 2008 Mathieu Desnoyers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +extern struct tracepoint __start___tracepoints[]; +extern struct tracepoint __stop___tracepoints[]; + +/* Set to 1 to enable tracepoint debug output */ +static const int tracepoint_debug; + +/* + * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the + * builtin and module tracepoints and the hash table. + */ +static DEFINE_MUTEX(tracepoints_mutex); + +/* + * Tracepoint hash table, containing the active tracepoints. + * Protected by tracepoints_mutex. + */ +#define TRACEPOINT_HASH_BITS 6 +#define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS) + +/* + * Note about RCU : + * It is used to to delay the free of multiple probes array until a quiescent + * state is reached. + * Tracepoint entries modifications are protected by the tracepoints_mutex. + */ +struct tracepoint_entry { + struct hlist_node hlist; + void **funcs; + int refcount; /* Number of times armed. 0 if disarmed. */ + struct rcu_head rcu; + void *oldptr; + unsigned char rcu_pending:1; + char name[0]; +}; + +static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE]; + +static void free_old_closure(struct rcu_head *head) +{ + struct tracepoint_entry *entry = container_of(head, + struct tracepoint_entry, rcu); + kfree(entry->oldptr); + /* Make sure we free the data before setting the pending flag to 0 */ + smp_wmb(); + entry->rcu_pending = 0; +} + +static void tracepoint_entry_free_old(struct tracepoint_entry *entry, void *old) +{ + if (!old) + return; + entry->oldptr = old; + entry->rcu_pending = 1; + /* write rcu_pending before calling the RCU callback */ + smp_wmb(); +#ifdef CONFIG_PREEMPT_RCU + synchronize_sched(); /* Until we have the call_rcu_sched() */ +#endif + call_rcu(&entry->rcu, free_old_closure); +} + +static void debug_print_probes(struct tracepoint_entry *entry) +{ + int i; + + if (!tracepoint_debug) + return; + + for (i = 0; entry->funcs[i]; i++) + printk(KERN_DEBUG "Probe %d : %p\n", i, entry->funcs[i]); +} + +static void * +tracepoint_entry_add_probe(struct tracepoint_entry *entry, void *probe) +{ + int nr_probes = 0; + void **old, **new; + + WARN_ON(!probe); + + debug_print_probes(entry); + old = entry->funcs; + if (old) { + /* (N -> N+1), (N != 0, 1) probes */ + for (nr_probes = 0; old[nr_probes]; nr_probes++) + if (old[nr_probes] == probe) + return ERR_PTR(-EEXIST); + } + /* + 2 : one for new probe, one for NULL func */ + new = kzalloc((nr_probes + 2) * sizeof(void *), GFP_KERNEL); + if (new == NULL) + return ERR_PTR(-ENOMEM); + if (old) + memcpy(new, old, nr_probes * sizeof(void *)); + new[nr_probes] = probe; + entry->refcount = nr_probes + 1; + entry->funcs = new; + debug_print_probes(entry); + return old; +} + +static void * +tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe) +{ + int nr_probes = 0, nr_del = 0, i; + void **old, **new; + + old = entry->funcs; + + debug_print_probes(entry); + /* (N -> M), (N > 1, M >= 0) probes */ + for (nr_probes = 0; old[nr_probes]; nr_probes++) { + if ((!probe || old[nr_probes] == probe)) + nr_del++; + } + + if (nr_probes - nr_del == 0) { + /* N -> 0, (N > 1) */ + entry->funcs = NULL; + entry->refcount = 0; + debug_print_probes(entry); + return old; + } else { + int j = 0; + /* N -> M, (N > 1, M > 0) */ + /* + 1 for NULL */ + new = kzalloc((nr_probes - nr_del + 1) + * sizeof(void *), GFP_KERNEL); + if (new == NULL) + return ERR_PTR(-ENOMEM); + for (i = 0; old[i]; i++) + if ((probe && old[i] != probe)) + new[j++] = old[i]; + entry->refcount = nr_probes - nr_del; + entry->funcs = new; + } + debug_print_probes(entry); + return old; +} + +/* + * Get tracepoint if the tracepoint is present in the tracepoint hash table. + * Must be called with tracepoints_mutex held. + * Returns NULL if not present. + */ +static struct tracepoint_entry *get_tracepoint(const char *name) +{ + struct hlist_head *head; + struct hlist_node *node; + struct tracepoint_entry *e; + u32 hash = jhash(name, strlen(name), 0); + + head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + hlist_for_each_entry(e, node, head, hlist) { + if (!strcmp(name, e->name)) + return e; + } + return NULL; +} + +/* + * Add the tracepoint to the tracepoint hash table. Must be called with + * tracepoints_mutex held. + */ +static struct tracepoint_entry *add_tracepoint(const char *name) +{ + struct hlist_head *head; + struct hlist_node *node; + struct tracepoint_entry *e; + size_t name_len = strlen(name) + 1; + u32 hash = jhash(name, name_len-1, 0); + + head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + hlist_for_each_entry(e, node, head, hlist) { + if (!strcmp(name, e->name)) { + printk(KERN_NOTICE + "tracepoint %s busy\n", name); + return ERR_PTR(-EEXIST); /* Already there */ + } + } + /* + * Using kmalloc here to allocate a variable length element. Could + * cause some memory fragmentation if overused. + */ + e = kmalloc(sizeof(struct tracepoint_entry) + name_len, GFP_KERNEL); + if (!e) + return ERR_PTR(-ENOMEM); + memcpy(&e->name[0], name, name_len); + e->funcs = NULL; + e->refcount = 0; + e->rcu_pending = 0; + hlist_add_head(&e->hlist, head); + return e; +} + +/* + * Remove the tracepoint from the tracepoint hash table. Must be called with + * mutex_lock held. + */ +static int remove_tracepoint(const char *name) +{ + struct hlist_head *head; + struct hlist_node *node; + struct tracepoint_entry *e; + int found = 0; + size_t len = strlen(name) + 1; + u32 hash = jhash(name, len-1, 0); + + head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + hlist_for_each_entry(e, node, head, hlist) { + if (!strcmp(name, e->name)) { + found = 1; + break; + } + } + if (!found) + return -ENOENT; + if (e->refcount) + return -EBUSY; + hlist_del(&e->hlist); + /* Make sure the call_rcu has been executed */ + if (e->rcu_pending) + rcu_barrier(); + kfree(e); + return 0; +} + +/* + * Sets the probe callback corresponding to one tracepoint. + */ +static void set_tracepoint(struct tracepoint_entry **entry, + struct tracepoint *elem, int active) +{ + WARN_ON(strcmp((*entry)->name, elem->name) != 0); + + /* + * rcu_assign_pointer has a smp_wmb() which makes sure that the new + * probe callbacks array is consistent before setting a pointer to it. + * This array is referenced by __DO_TRACE from + * include/linux/tracepoints.h. A matching smp_read_barrier_depends() + * is used. + */ + rcu_assign_pointer(elem->funcs, (*entry)->funcs); + elem->state = active; +} + +/* + * Disable a tracepoint and its probe callback. + * Note: only waiting an RCU period after setting elem->call to the empty + * function insures that the original callback is not used anymore. This insured + * by preempt_disable around the call site. + */ +static void disable_tracepoint(struct tracepoint *elem) +{ + elem->state = 0; +} + +/** + * tracepoint_update_probe_range - Update a probe range + * @begin: beginning of the range + * @end: end of the range + * + * Updates the probe callback corresponding to a range of tracepoints. + */ +void tracepoint_update_probe_range(struct tracepoint *begin, + struct tracepoint *end) +{ + struct tracepoint *iter; + struct tracepoint_entry *mark_entry; + + mutex_lock(&tracepoints_mutex); + for (iter = begin; iter < end; iter++) { + mark_entry = get_tracepoint(iter->name); + if (mark_entry) { + set_tracepoint(&mark_entry, iter, + !!mark_entry->refcount); + } else { + disable_tracepoint(iter); + } + } + mutex_unlock(&tracepoints_mutex); +} + +/* + * Update probes, removing the faulty probes. + */ +static void tracepoint_update_probes(void) +{ + /* Core kernel tracepoints */ + tracepoint_update_probe_range(__start___tracepoints, + __stop___tracepoints); + /* tracepoints in modules. */ + module_update_tracepoints(); +} + +/** + * tracepoint_probe_register - Connect a probe to a tracepoint + * @name: tracepoint name + * @probe: probe handler + * + * Returns 0 if ok, error value on error. + * The probe address must at least be aligned on the architecture pointer size. + */ +int tracepoint_probe_register(const char *name, void *probe) +{ + struct tracepoint_entry *entry; + int ret = 0; + void *old; + + mutex_lock(&tracepoints_mutex); + entry = get_tracepoint(name); + if (!entry) { + entry = add_tracepoint(name); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry); + goto end; + } + } + /* + * If we detect that a call_rcu is pending for this tracepoint, + * make sure it's executed now. + */ + if (entry->rcu_pending) + rcu_barrier(); + old = tracepoint_entry_add_probe(entry, probe); + if (IS_ERR(old)) { + ret = PTR_ERR(old); + goto end; + } + mutex_unlock(&tracepoints_mutex); + tracepoint_update_probes(); /* may update entry */ + mutex_lock(&tracepoints_mutex); + entry = get_tracepoint(name); + WARN_ON(!entry); + tracepoint_entry_free_old(entry, old); +end: + mutex_unlock(&tracepoints_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(tracepoint_probe_register); + +/** + * tracepoint_probe_unregister - Disconnect a probe from a tracepoint + * @name: tracepoint name + * @probe: probe function pointer + * + * We do not need to call a synchronize_sched to make sure the probes have + * finished running before doing a module unload, because the module unload + * itself uses stop_machine(), which insures that every preempt disabled section + * have finished. + */ +int tracepoint_probe_unregister(const char *name, void *probe) +{ + struct tracepoint_entry *entry; + void *old; + int ret = -ENOENT; + + mutex_lock(&tracepoints_mutex); + entry = get_tracepoint(name); + if (!entry) + goto end; + if (entry->rcu_pending) + rcu_barrier(); + old = tracepoint_entry_remove_probe(entry, probe); + mutex_unlock(&tracepoints_mutex); + tracepoint_update_probes(); /* may update entry */ + mutex_lock(&tracepoints_mutex); + entry = get_tracepoint(name); + if (!entry) + goto end; + tracepoint_entry_free_old(entry, old); + remove_tracepoint(name); /* Ignore busy error message */ + ret = 0; +end: + mutex_unlock(&tracepoints_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(tracepoint_probe_unregister); + +/** + * tracepoint_get_iter_range - Get a next tracepoint iterator given a range. + * @tracepoint: current tracepoints (in), next tracepoint (out) + * @begin: beginning of the range + * @end: end of the range + * + * Returns whether a next tracepoint has been found (1) or not (0). + * Will return the first tracepoint in the range if the input tracepoint is + * NULL. + */ +int tracepoint_get_iter_range(struct tracepoint **tracepoint, + struct tracepoint *begin, struct tracepoint *end) +{ + if (!*tracepoint && begin != end) { + *tracepoint = begin; + return 1; + } + if (*tracepoint >= begin && *tracepoint < end) + return 1; + return 0; +} +EXPORT_SYMBOL_GPL(tracepoint_get_iter_range); + +static void tracepoint_get_iter(struct tracepoint_iter *iter) +{ + int found = 0; + + /* Core kernel tracepoints */ + if (!iter->module) { + found = tracepoint_get_iter_range(&iter->tracepoint, + __start___tracepoints, __stop___tracepoints); + if (found) + goto end; + } + /* tracepoints in modules. */ + found = module_get_iter_tracepoints(iter); +end: + if (!found) + tracepoint_iter_reset(iter); +} + +void tracepoint_iter_start(struct tracepoint_iter *iter) +{ + tracepoint_get_iter(iter); +} +EXPORT_SYMBOL_GPL(tracepoint_iter_start); + +void tracepoint_iter_next(struct tracepoint_iter *iter) +{ + iter->tracepoint++; + /* + * iter->tracepoint may be invalid because we blindly incremented it. + * Make sure it is valid by marshalling on the tracepoints, getting the + * tracepoints from following modules if necessary. + */ + tracepoint_get_iter(iter); +} +EXPORT_SYMBOL_GPL(tracepoint_iter_next); + +void tracepoint_iter_stop(struct tracepoint_iter *iter) +{ +} +EXPORT_SYMBOL_GPL(tracepoint_iter_stop); + +void tracepoint_iter_reset(struct tracepoint_iter *iter) +{ + iter->module = NULL; + iter->tracepoint = NULL; +} +EXPORT_SYMBOL_GPL(tracepoint_iter_reset); -- cgit v1.1 From 0a16b6075843325dc402edf80c1662838b929aff Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 18 Jul 2008 12:16:17 -0400 Subject: tracing, sched: LTTng instrumentation - scheduler Instrument the scheduler activity (sched_switch, migration, wakeups, wait for a task, signal delivery) and process/thread creation/destruction (fork, exit, kthread stop). Actually, kthread creation is not instrumented in this patch because it is architecture dependent. It allows to connect tracers such as ftrace which detects scheduling latencies, good/bad scheduler decisions. Tools like LTTng can export this scheduler information along with instrumentation of the rest of the kernel activity to perform post-mortem analysis on the scheduler activity. About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. See the "Tracepoints" patch header for performance result detail. Changelog : - Change instrumentation location and parameter to match ftrace instrumentation, previously done with kernel markers. [ mingo@elte.hu: conflict resolutions ] Signed-off-by: Mathieu Desnoyers Acked-by: 'Peter Zijlstra' Signed-off-by: Ingo Molnar --- kernel/exit.c | 10 +++++++++- kernel/fork.c | 3 +++ kernel/kthread.c | 5 +++++ kernel/sched.c | 17 ++++++----------- kernel/signal.c | 3 +++ 5 files changed, 26 insertions(+), 12 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 85a83c8..7b71f87 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include @@ -149,7 +150,10 @@ static void __exit_signal(struct task_struct *tsk) static void delayed_put_task_struct(struct rcu_head *rhp) { - put_task_struct(container_of(rhp, struct task_struct, rcu)); + struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); + + trace_sched_process_free(tsk); + put_task_struct(tsk); } @@ -1074,6 +1078,8 @@ NORET_TYPE void do_exit(long code) if (group_dead) acct_process(); + trace_sched_process_exit(tsk); + exit_sem(tsk); exit_files(tsk); exit_fs(tsk); @@ -1675,6 +1681,8 @@ static long do_wait(enum pid_type type, struct pid *pid, int options, struct task_struct *tsk; int retval; + trace_sched_process_wait(pid); + add_wait_queue(¤t->signal->wait_chldexit,&wait); repeat: /* diff --git a/kernel/fork.c b/kernel/fork.c index 30de644..cfaff92 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include @@ -1364,6 +1365,8 @@ long do_fork(unsigned long clone_flags, if (!IS_ERR(p)) { struct completion vfork; + trace_sched_process_fork(current, p); + nr = task_pid_vnr(p); if (clone_flags & CLONE_PARENT_SETTID) diff --git a/kernel/kthread.c b/kernel/kthread.c index 96cff2f..50598e29 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -13,6 +13,7 @@ #include #include #include +#include #define KTHREAD_NICE_LEVEL (-5) @@ -206,6 +207,8 @@ int kthread_stop(struct task_struct *k) /* It could exit after stop_info.k set, but before wake_up_process. */ get_task_struct(k); + trace_sched_kthread_stop(k); + /* Must init completion *before* thread sees kthread_stop_info.k */ init_completion(&kthread_stop_info.done); smp_wmb(); @@ -221,6 +224,8 @@ int kthread_stop(struct task_struct *k) ret = kthread_stop_info.err; mutex_unlock(&kthread_stop_lock); + trace_sched_kthread_stop_ret(ret); + return ret; } EXPORT_SYMBOL(kthread_stop); diff --git a/kernel/sched.c b/kernel/sched.c index 6f23059..3d1ad13 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -71,6 +71,7 @@ #include #include #include +#include #include #include @@ -1936,6 +1937,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) * just go back and repeat. */ rq = task_rq_lock(p, &flags); + trace_sched_wait_task(rq, p); running = task_running(rq, p); on_rq = p->se.on_rq; ncsw = 0; @@ -2297,9 +2299,7 @@ out_activate: success = 1; out_running: - trace_mark(kernel_sched_wakeup, - "pid %d state %ld ## rq %p task %p rq->curr %p", - p->pid, p->state, rq, p, rq->curr); + trace_sched_wakeup(rq, p); check_preempt_curr(rq, p, sync); p->state = TASK_RUNNING; @@ -2432,9 +2432,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) p->sched_class->task_new(rq, p); inc_nr_running(rq); } - trace_mark(kernel_sched_wakeup_new, - "pid %d state %ld ## rq %p task %p rq->curr %p", - p->pid, p->state, rq, p, rq->curr); + trace_sched_wakeup_new(rq, p); check_preempt_curr(rq, p, 0); #ifdef CONFIG_SMP if (p->sched_class->task_wake_up) @@ -2607,11 +2605,7 @@ context_switch(struct rq *rq, struct task_struct *prev, struct mm_struct *mm, *oldmm; prepare_task_switch(rq, prev, next); - trace_mark(kernel_sched_schedule, - "prev_pid %d next_pid %d prev_state %ld " - "## rq %p prev %p next %p", - prev->pid, next->pid, prev->state, - rq, prev, next); + trace_sched_switch(rq, prev, next); mm = next->mm; oldmm = prev->active_mm; /* @@ -2851,6 +2845,7 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu) || unlikely(!cpu_active(dest_cpu))) goto out; + trace_sched_migrate_task(rq, p, dest_cpu); /* force the process onto the specified CPU */ if (migrate_task(p, dest_cpu, &req)) { /* Need to wait for migration thread (might exit: take ref). */ diff --git a/kernel/signal.c b/kernel/signal.c index e661b01..bf40ecc 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -803,6 +804,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, struct sigpending *pending; struct sigqueue *q; + trace_sched_signal_send(sig, t); + assert_spin_locked(&t->sighand->siglock); if (!prepare_signal(sig, t)) return 0; -- cgit v1.1 From b07c3f193a8074aa4afe43cfa8ae38ec4c7ccfa9 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 18 Jul 2008 12:16:17 -0400 Subject: ftrace: port to tracepoints Porting the trace_mark() used by ftrace to tracepoints. (cleanup) Changelog : - Change error messages : marker -> tracepoint [ mingo@elte.hu: conflict resolutions ] Signed-off-by: Mathieu Desnoyers Acked-by: 'Peter Zijlstra' Signed-off-by: Ingo Molnar --- kernel/trace/trace_sched_switch.c | 120 +++++++-------------------------- kernel/trace/trace_sched_wakeup.c | 135 ++++++++++---------------------------- 2 files changed, 58 insertions(+), 197 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index cb817a2..789e927 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -9,8 +9,8 @@ #include #include #include -#include #include +#include #include "trace.h" @@ -19,16 +19,17 @@ static int __read_mostly tracer_enabled; static atomic_t sched_ref; static void -sched_switch_func(void *private, void *__rq, struct task_struct *prev, +probe_sched_switch(struct rq *__rq, struct task_struct *prev, struct task_struct *next) { - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; unsigned long flags; long disabled; int cpu; + if (!atomic_read(&sched_ref)) + return; + tracing_record_cmdline(prev); tracing_record_cmdline(next); @@ -37,95 +38,42 @@ sched_switch_func(void *private, void *__rq, struct task_struct *prev, local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; + data = ctx_trace->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - tracing_sched_switch_trace(tr, data, prev, next, flags); + tracing_sched_switch_trace(ctx_trace, data, prev, next, flags); atomic_dec(&data->disabled); local_irq_restore(flags); } -static notrace void -sched_switch_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *prev; - struct task_struct *next; - struct rq *__rq; - - if (!atomic_read(&sched_ref)) - return; - - /* skip prev_pid %d next_pid %d prev_state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, int); - (void)va_arg(*args, long); - __rq = va_arg(*args, typeof(__rq)); - prev = va_arg(*args, typeof(prev)); - next = va_arg(*args, typeof(next)); - - /* - * If tracer_switch_func only points to the local - * switch func, it still needs the ptr passed to it. - */ - sched_switch_func(probe_data, __rq, prev, next); -} - static void -wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct - task_struct *curr) +probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) { - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; unsigned long flags; long disabled; int cpu; - if (!tracer_enabled) + if (!likely(tracer_enabled)) return; - tracing_record_cmdline(curr); + tracing_record_cmdline(current); local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; + data = ctx_trace->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - tracing_sched_wakeup_trace(tr, data, wakee, curr, flags); + tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, + flags); atomic_dec(&data->disabled); local_irq_restore(flags); } -static notrace void -wake_up_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *curr; - struct task_struct *task; - struct rq *__rq; - - if (likely(!tracer_enabled)) - return; - - /* Skip pid %d state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, long); - /* now get the meat: "rq %p task %p rq->curr %p" */ - __rq = va_arg(*args, typeof(__rq)); - task = va_arg(*args, typeof(task)); - curr = va_arg(*args, typeof(curr)); - - tracing_record_cmdline(task); - tracing_record_cmdline(curr); - - wakeup_func(probe_data, __rq, task, curr); -} - static void sched_switch_reset(struct trace_array *tr) { int cpu; @@ -140,60 +88,40 @@ static int tracing_sched_register(void) { int ret; - ret = marker_probe_register("kernel_sched_wakeup", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &ctx_trace); + ret = register_trace_sched_wakeup(probe_sched_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup\n"); return ret; } - ret = marker_probe_register("kernel_sched_wakeup_new", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &ctx_trace); + ret = register_trace_sched_wakeup_new(probe_sched_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup_new\n"); goto fail_deprobe; } - ret = marker_probe_register("kernel_sched_schedule", - "prev_pid %d next_pid %d prev_state %ld " - "## rq %p prev %p next %p", - sched_switch_callback, - &ctx_trace); + ret = register_trace_sched_switch(probe_sched_switch); if (ret) { - pr_info("sched trace: Couldn't add marker" + pr_info("sched trace: Couldn't activate tracepoint" " probe to kernel_sched_schedule\n"); goto fail_deprobe_wake_new; } return ret; fail_deprobe_wake_new: - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_wakeup_new(probe_sched_wakeup); fail_deprobe: - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_wakeup(probe_sched_wakeup); return ret; } static void tracing_sched_unregister(void) { - marker_probe_unregister("kernel_sched_schedule", - sched_switch_callback, - &ctx_trace); - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &ctx_trace); - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_switch(probe_sched_switch); + unregister_trace_sched_wakeup_new(probe_sched_wakeup); + unregister_trace_sched_wakeup(probe_sched_wakeup); } static void tracing_start_sched_switch(void) diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index e303ccb..08206b4 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -15,7 +15,7 @@ #include #include #include -#include +#include #include "trace.h" @@ -112,18 +112,18 @@ static int report_latency(cycle_t delta) } static void notrace -wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, +probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { unsigned long latency = 0, t0 = 0, t1 = 0; - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; cycle_t T0, T1, delta; unsigned long flags; long disabled; int cpu; + tracing_record_cmdline(prev); + if (unlikely(!tracer_enabled)) return; @@ -140,11 +140,11 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, return; /* The task we are waiting for is waking up */ - data = tr->data[wakeup_cpu]; + data = wakeup_trace->data[wakeup_cpu]; /* disable local data, not wakeup_cpu data */ cpu = raw_smp_processor_id(); - disabled = atomic_inc_return(&tr->data[cpu]->disabled); + disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); if (likely(disabled != 1)) goto out; @@ -155,7 +155,7 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, if (unlikely(!tracer_enabled || next != wakeup_task)) goto out_unlock; - trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags); + trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags); /* * usecs conversion is slow so we try to delay the conversion @@ -174,39 +174,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, t0 = nsecs_to_usecs(T0); t1 = nsecs_to_usecs(T1); - update_max_tr(tr, wakeup_task, wakeup_cpu); + update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); out_unlock: - __wakeup_reset(tr); + __wakeup_reset(wakeup_trace); __raw_spin_unlock(&wakeup_lock); local_irq_restore(flags); out: - atomic_dec(&tr->data[cpu]->disabled); -} - -static notrace void -sched_switch_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *prev; - struct task_struct *next; - struct rq *__rq; - - /* skip prev_pid %d next_pid %d prev_state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, int); - (void)va_arg(*args, long); - __rq = va_arg(*args, typeof(__rq)); - prev = va_arg(*args, typeof(prev)); - next = va_arg(*args, typeof(next)); - - tracing_record_cmdline(prev); - - /* - * If tracer_switch_func only points to the local - * switch func, it still needs the ptr passed to it. - */ - wakeup_sched_switch(probe_data, __rq, prev, next); + atomic_dec(&wakeup_trace->data[cpu]->disabled); } static void __wakeup_reset(struct trace_array *tr) @@ -240,19 +215,24 @@ static void wakeup_reset(struct trace_array *tr) } static void -wakeup_check_start(struct trace_array *tr, struct task_struct *p, - struct task_struct *curr) +probe_wakeup(struct rq *rq, struct task_struct *p) { int cpu = smp_processor_id(); unsigned long flags; long disabled; + if (likely(!tracer_enabled)) + return; + + tracing_record_cmdline(p); + tracing_record_cmdline(current); + if (likely(!rt_task(p)) || p->prio >= wakeup_prio || - p->prio >= curr->prio) + p->prio >= current->prio) return; - disabled = atomic_inc_return(&tr->data[cpu]->disabled); + disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); if (unlikely(disabled != 1)) goto out; @@ -264,7 +244,7 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p, goto out_locked; /* reset the trace */ - __wakeup_reset(tr); + __wakeup_reset(wakeup_trace); wakeup_cpu = task_cpu(p); wakeup_prio = p->prio; @@ -274,74 +254,37 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p, local_save_flags(flags); - tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); - trace_function(tr, tr->data[wakeup_cpu], + wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); + trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu], CALLER_ADDR1, CALLER_ADDR2, flags); out_locked: __raw_spin_unlock(&wakeup_lock); out: - atomic_dec(&tr->data[cpu]->disabled); -} - -static notrace void -wake_up_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct trace_array **ptr = probe_data; - struct trace_array *tr = *ptr; - struct task_struct *curr; - struct task_struct *task; - struct rq *__rq; - - if (likely(!tracer_enabled)) - return; - - /* Skip pid %d state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, long); - /* now get the meat: "rq %p task %p rq->curr %p" */ - __rq = va_arg(*args, typeof(__rq)); - task = va_arg(*args, typeof(task)); - curr = va_arg(*args, typeof(curr)); - - tracing_record_cmdline(task); - tracing_record_cmdline(curr); - - wakeup_check_start(tr, task, curr); + atomic_dec(&wakeup_trace->data[cpu]->disabled); } static void start_wakeup_tracer(struct trace_array *tr) { int ret; - ret = marker_probe_register("kernel_sched_wakeup", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &wakeup_trace); + ret = register_trace_sched_wakeup(probe_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup\n"); return; } - ret = marker_probe_register("kernel_sched_wakeup_new", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &wakeup_trace); + ret = register_trace_sched_wakeup_new(probe_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup_new\n"); goto fail_deprobe; } - ret = marker_probe_register("kernel_sched_schedule", - "prev_pid %d next_pid %d prev_state %ld " - "## rq %p prev %p next %p", - sched_switch_callback, - &wakeup_trace); + ret = register_trace_sched_switch(probe_wakeup_sched_switch); if (ret) { - pr_info("sched trace: Couldn't add marker" + pr_info("sched trace: Couldn't activate tracepoint" " probe to kernel_sched_schedule\n"); goto fail_deprobe_wake_new; } @@ -363,28 +306,18 @@ static void start_wakeup_tracer(struct trace_array *tr) return; fail_deprobe_wake_new: - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_wakeup_new(probe_wakeup); fail_deprobe: - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_wakeup(probe_wakeup); } static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; unregister_ftrace_function(&trace_ops); - marker_probe_unregister("kernel_sched_schedule", - sched_switch_callback, - &wakeup_trace); - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &wakeup_trace); - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_switch(probe_wakeup_sched_switch); + unregister_trace_sched_wakeup_new(probe_wakeup); + unregister_trace_sched_wakeup(probe_wakeup); } static void wakeup_tracer_init(struct trace_array *tr) -- cgit v1.1 From 5f87f1121895dc09d2d1c1db5f14af6aa4ce3e94 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 23 Jul 2008 14:15:22 +0200 Subject: tracing: clean up tracepoints kconfig structure do not expose users to CONFIG_TRACEPOINTS - tracers can select it just fine. update ftrace to select CONFIG_TRACEPOINTS. Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 263e9e6..cae2637 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -14,6 +14,7 @@ config TRACING bool select DEBUG_FS select STACKTRACE + select TRACEPOINTS config FTRACE bool "Kernel Function Tracer" -- cgit v1.1 From 9795302acf2817d0842e56d23df6008e43df0970 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 24 Jul 2008 16:37:23 -0400 Subject: tracepoints: use TABLE_SIZE macro Steven Rostedt suggested: | Wouldn't it look nicer to have: (TRACEPOINT_TABLE_SIZE - 1) ? Signed-off-by: Mathieu Desnoyers Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 42e86dd..c7c62a4 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -177,7 +177,7 @@ static struct tracepoint_entry *get_tracepoint(const char *name) struct tracepoint_entry *e; u32 hash = jhash(name, strlen(name), 0); - head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; hlist_for_each_entry(e, node, head, hlist) { if (!strcmp(name, e->name)) return e; @@ -197,7 +197,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name) size_t name_len = strlen(name) + 1; u32 hash = jhash(name, name_len-1, 0); - head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; hlist_for_each_entry(e, node, head, hlist) { if (!strcmp(name, e->name)) { printk(KERN_NOTICE @@ -233,7 +233,7 @@ static int remove_tracepoint(const char *name) size_t len = strlen(name) + 1; u32 hash = jhash(name, len-1, 0); - head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)]; + head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; hlist_for_each_entry(e, node, head, hlist) { if (!strcmp(name, e->name)) { found = 1; -- cgit v1.1 From 36dcd67ae994fece615b7c700958d215e884b9ae Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 29 Jul 2008 12:00:59 +0200 Subject: ftrace: ignore functions that cannot be kprobe-ed kprobes already has an extensive list of annotations for functions that should not be instrumented. Add notrace annotations to these functions as well. This is particularly useful for functions called by the NMI path. Signed-off-by: Ingo Molnar --- kernel/notifier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/notifier.c b/kernel/notifier.c index 823be115..4282c0a 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -550,7 +550,7 @@ EXPORT_SYMBOL(unregister_reboot_notifier); static ATOMIC_NOTIFIER_HEAD(die_chain); -int notify_die(enum die_val val, const char *str, +int notrace notify_die(enum die_val val, const char *str, struct pt_regs *regs, long err, int trap, int sig) { struct die_args args = { -- cgit v1.1 From 8da3821ba5634497da63d58a69e24a97697c4a2b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Aug 2008 15:45:07 -0400 Subject: ftrace: create __mcount_loc section This patch creates a section in the kernel called "__mcount_loc". This will hold a list of pointers to the mcount relocation for each call site of mcount. For example: objdump -dr init/main.o [...] Disassembly of section .text: 0000000000000000 : 0: 55 push %rbp [...] 000000000000017b : 17b: 55 push %rbp 17c: 48 89 e5 mov %rsp,%rbp 17f: 53 push %rbx 180: 48 83 ec 08 sub $0x8,%rsp 184: e8 00 00 00 00 callq 189 185: R_X86_64_PC32 mcount+0xfffffffffffffffc [...] We will add a section to point to each function call. .section __mcount_loc,"a",@progbits [...] .quad .text + 0x185 [...] The offset to of the mcount call site in init_post is an offset from the start of the section, and not the start of the function init_post. The mcount relocation is at the call site 0x185 from the start of the .text section. .text + 0x185 == init_post + 0xa We need a way to add this __mcount_loc section in a way that we do not lose the relocations after final link. The .text section here will be attached to all other .text sections after final link and the offsets will be meaningless. We need to keep track of where these .text sections are. To do this, we use the start of the first function in the section. do_one_initcall. We can make a tmp.s file with this function as a reference to the start of the .text section. .section __mcount_loc,"a",@progbits [...] .quad do_one_initcall + 0x185 [...] Then we can compile the tmp.s into a tmp.o gcc -c tmp.s -o tmp.o And link it into back into main.o. ld -r main.o tmp.o -o tmp_main.o mv tmp_main.o main.o But we have a problem. What happens if the first function in a section is not exported, and is a static function. The linker will not let the tmp.o use it. This case exists in main.o as well. Disassembly of section .init.text: 0000000000000000 : 0: 55 push %rbp 1: 48 89 e5 mov %rsp,%rbp 4: e8 00 00 00 00 callq 9 5: R_X86_64_PC32 mcount+0xfffffffffffffffc The first function in .init.text is a static function. 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices The lowercase 't' means that set_reset_devices is local and is not exported. If we simply try to link the tmp.o with the set_reset_devices we end up with two symbols: one local and one global. .section __mcount_loc,"a",@progbits .quad set_reset_devices + 0x10 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices U set_reset_devices We still have an undefined reference to set_reset_devices, and if we try to compile the kernel, we will end up with an undefined reference to set_reset_devices, or even worst, it could be exported someplace else, and then we will have a reference to the wrong location. To handle this case, we make an intermediate step using objcopy. We convert set_reset_devices into a global exported symbol before linking it with tmp.o and set it back afterwards. 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 T set_reset_devices 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 T set_reset_devices 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices Now we have a section in main.o called __mcount_loc that we can place somewhere in the kernel using vmlinux.ld.S and access it to convert all these locations that call mcount into nops before starting SMP and thus, eliminating the need to do this with kstop_machine. Note, A well documented perl script (scripts/recordmcount.pl) is used to do all this in one location. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index cae2637..14d9505 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -7,6 +7,9 @@ config HAVE_FTRACE config HAVE_DYNAMIC_FTRACE bool +config HAVE_FTRACE_MCOUNT_RECORD + bool + config TRACER_MAX_TRACE bool @@ -122,6 +125,11 @@ config DYNAMIC_FTRACE were made. If so, it runs stop_machine (stops all CPUS) and modifies the code to jump over the call to ftrace. +config FTRACE_MCOUNT_RECORD + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_FTRACE_MCOUNT_RECORD + config FTRACE_SELFTEST bool -- cgit v1.1 From 68bf21aa15c85d2e9b623dcda2b1ed8893275fa1 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Aug 2008 15:45:08 -0400 Subject: ftrace: mcount call site on boot nops core This is the infrastructure to the converting the mcount call sites recorded by the __mcount_loc section into nops on boot. It also allows for using these sites to enable tracing as normal. When the __mcount_loc section is used, the "ftraced" kernel thread is disabled. This uses the current infrastructure to record the mcount call sites as well as convert them to nops. The mcount function is kept as a stub on boot up and not converted to the ftrace_record_ip function. We use the ftrace_record_ip to only record from the table. This patch does not handle modules. That comes with a later patch. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 148 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 105 insertions(+), 43 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f6e3af3..df96d59 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -792,47 +792,7 @@ static int ftrace_update_code(void) return 1; } -static int ftraced(void *ignore) -{ - unsigned long usecs; - - while (!kthread_should_stop()) { - - set_current_state(TASK_INTERRUPTIBLE); - - /* check once a second */ - schedule_timeout(HZ); - - if (unlikely(ftrace_disabled)) - continue; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (!ftraced_suspend && !ftraced_stop && - ftrace_update_code()) { - usecs = nsecs_to_usecs(ftrace_update_time); - if (ftrace_update_tot_cnt > 100000) { - ftrace_update_tot_cnt = 0; - pr_info("hm, dftrace overflow: %lu change%s" - " (%lu total) in %lu usec%s\n", - ftrace_update_cnt, - ftrace_update_cnt != 1 ? "s" : "", - ftrace_update_tot_cnt, - usecs, usecs != 1 ? "s" : ""); - ftrace_disabled = 1; - WARN_ON_ONCE(1); - } - } - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - ftrace_shutdown_replenish(); - } - __set_current_state(TASK_RUNNING); - return 0; -} - -static int __init ftrace_dyn_table_alloc(void) +static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) { struct ftrace_page *pg; int cnt; @@ -859,7 +819,9 @@ static int __init ftrace_dyn_table_alloc(void) pg = ftrace_pages = ftrace_pages_start; - cnt = NR_TO_INIT / ENTRIES_PER_PAGE; + cnt = num_to_init / ENTRIES_PER_PAGE; + pr_info("ftrace: allocating %ld hash entries in %d pages\n", + num_to_init, cnt); for (i = 0; i < cnt; i++) { pg->next = (void *)get_zeroed_page(GFP_KERNEL); @@ -1556,6 +1518,104 @@ static __init int ftrace_init_debugfs(void) fs_initcall(ftrace_init_debugfs); +#ifdef CONFIG_FTRACE_MCOUNT_RECORD +static int ftrace_convert_nops(unsigned long *start, + unsigned long *end) +{ + unsigned long *p; + unsigned long addr; + unsigned long flags; + + p = start; + while (p < end) { + addr = ftrace_call_adjust(*p++); + ftrace_record_ip(addr); + ftrace_shutdown_replenish(); + } + + /* p is ignored */ + local_irq_save(flags); + __ftrace_update_code(p); + local_irq_restore(flags); + + return 0; +} + +extern unsigned long __start_mcount_loc[]; +extern unsigned long __stop_mcount_loc[]; + +void __init ftrace_init(void) +{ + unsigned long count, addr, flags; + int ret; + + /* Keep the ftrace pointer to the stub */ + addr = (unsigned long)ftrace_stub; + + local_irq_save(flags); + ftrace_dyn_arch_init(&addr); + local_irq_restore(flags); + + /* ftrace_dyn_arch_init places the return code in addr */ + if (addr) + goto failed; + + count = __stop_mcount_loc - __start_mcount_loc; + + ret = ftrace_dyn_table_alloc(count); + if (ret) + goto failed; + + last_ftrace_enabled = ftrace_enabled = 1; + + ret = ftrace_convert_nops(__start_mcount_loc, + __stop_mcount_loc); + + return; + failed: + ftrace_disabled = 1; +} +#else /* CONFIG_FTRACE_MCOUNT_RECORD */ +static int ftraced(void *ignore) +{ + unsigned long usecs; + + while (!kthread_should_stop()) { + + set_current_state(TASK_INTERRUPTIBLE); + + /* check once a second */ + schedule_timeout(HZ); + + if (unlikely(ftrace_disabled)) + continue; + + mutex_lock(&ftrace_sysctl_lock); + mutex_lock(&ftraced_lock); + if (!ftraced_suspend && !ftraced_stop && + ftrace_update_code()) { + usecs = nsecs_to_usecs(ftrace_update_time); + if (ftrace_update_tot_cnt > 100000) { + ftrace_update_tot_cnt = 0; + pr_info("hm, dftrace overflow: %lu change%s" + " (%lu total) in %lu usec%s\n", + ftrace_update_cnt, + ftrace_update_cnt != 1 ? "s" : "", + ftrace_update_tot_cnt, + usecs, usecs != 1 ? "s" : ""); + ftrace_disabled = 1; + WARN_ON_ONCE(1); + } + } + mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_sysctl_lock); + + ftrace_shutdown_replenish(); + } + __set_current_state(TASK_RUNNING); + return 0; +} + static int __init ftrace_dynamic_init(void) { struct task_struct *p; @@ -1572,7 +1632,7 @@ static int __init ftrace_dynamic_init(void) goto failed; } - ret = ftrace_dyn_table_alloc(); + ret = ftrace_dyn_table_alloc(NR_TO_INIT); if (ret) goto failed; @@ -1593,6 +1653,8 @@ static int __init ftrace_dynamic_init(void) } core_initcall(ftrace_dynamic_init); +#endif /* CONFIG_FTRACE_MCOUNT_RECORD */ + #else # define ftrace_startup() do { } while (0) # define ftrace_shutdown() do { } while (0) -- cgit v1.1 From 90d595fe5ca4b685465c068907e6e554760abea8 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Aug 2008 15:45:09 -0400 Subject: ftrace: enable mcount recording for modules This patch enables the loading of the __mcount_section of modules and changing all the callers of mcount into nops. The modification is done before the init_module function is called, so again, we do not need to use kstop_machine to make these changes. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/module.c | 11 +++++++++++ kernel/trace/ftrace.c | 5 +++++ 2 files changed, 16 insertions(+) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 661d73d..d753fd9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -47,6 +47,7 @@ #include #include #include +#include #if 0 #define DEBUGP printk @@ -1834,6 +1835,7 @@ static noinline struct module *load_module(void __user *umod, unsigned int markersstringsindex; unsigned int tracepointsindex; unsigned int tracepointsstringsindex; + unsigned int mcountindex; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ @@ -2124,6 +2126,9 @@ static noinline struct module *load_module(void __user *umod, tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints_strings"); + mcountindex = find_sec(hdr, sechdrs, secstrings, + "__mcount_loc"); + /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { const char *strtab = (char *)sechdrs[strindex].sh_addr; @@ -2184,6 +2189,12 @@ static noinline struct module *load_module(void __user *umod, mod->tracepoints + mod->num_tracepoints); #endif } + + if (mcountindex) { + void *mseg = (void *)sechdrs[mcountindex].sh_addr; + ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size); + } + err = module_finalize(hdr, sechdrs, mod); if (err < 0) goto cleanup; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index df96d59..ea45bb1c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1541,6 +1541,11 @@ static int ftrace_convert_nops(unsigned long *start, return 0; } +void ftrace_init_module(unsigned long *start, unsigned long *end) +{ + ftrace_convert_nops(start, end); +} + extern unsigned long __start_mcount_loc[]; extern unsigned long __stop_mcount_loc[]; -- cgit v1.1 From a9fdda33cd7c7519b082e37538fe790f9ff684bb Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Aug 2008 22:47:17 -0400 Subject: ftrace: do not show freed records in available_filter_functions Seems that freed records can appear in the available_filter_functions list. This patch fixes that. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ea45bb1c..8affb6d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -872,15 +872,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos) } } else { rec = &iter->pg->records[iter->idx++]; - if ((!(iter->flags & FTRACE_ITER_FAILURES) && + if ((rec->flags & FTRACE_FL_FREE) || + + (!(iter->flags & FTRACE_ITER_FAILURES) && (rec->flags & FTRACE_FL_FAILED)) || ((iter->flags & FTRACE_ITER_FAILURES) && - (!(rec->flags & FTRACE_FL_FAILED) || - (rec->flags & FTRACE_FL_FREE))) || - - ((iter->flags & FTRACE_ITER_FILTER) && - !(rec->flags & FTRACE_FL_FILTER)) || + !(rec->flags & FTRACE_FL_FAILED)) || ((iter->flags & FTRACE_ITER_NOTRACE) && !(rec->flags & FTRACE_FL_NOTRACE))) { -- cgit v1.1 From fed1939c64d2288938fdc1c367d49082da65e195 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Aug 2008 22:47:19 -0400 Subject: ftrace: remove old pointers to mcount When a mcount pointer is recorded into a table, it is used to add or remove calls to mcount (replacing them with nops). If the code is removed via removing a module, the pointers still exist. At modifying the code a check is always made to make sure the code being replaced is the code expected. In-other-words, the code being replaced is compared to what it is expected to be before being replaced. There is a very small chance that the code being replaced just happens to look like code that calls mcount (very small since the call to mcount is relative). To remove this chance, this patch adds ftrace_release to allow module unloading to remove the pointers to mcount within the module. Another change for init calls is made to not trace calls marked with __init. The tracing can not be started until after init is done anyway. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/module.c | 12 ++++++++---- kernel/trace/ftrace.c | 32 ++++++++++++++++++++++++++++++-- 2 files changed, 38 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index d753fd9..7576c2d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1431,6 +1431,9 @@ static void free_module(struct module *mod) /* Module unload stuff */ module_unload_free(mod); + /* release any pointers to mcount in this module */ + ftrace_release(mod->module_core, mod->core_size); + /* This may be NULL, but that's OK */ module_free(mod, mod->module_init); kfree(mod->args); @@ -1839,6 +1842,7 @@ static noinline struct module *load_module(void __user *umod, struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ + void *mseg; struct exception_table_entry *extable; mm_segment_t old_fs; @@ -2190,10 +2194,9 @@ static noinline struct module *load_module(void __user *umod, #endif } - if (mcountindex) { - void *mseg = (void *)sechdrs[mcountindex].sh_addr; - ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size); - } + /* sechdrs[0].sh_size is always zero */ + mseg = (void *)sechdrs[mcountindex].sh_addr; + ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size); err = module_finalize(hdr, sechdrs, mod); if (err < 0) @@ -2264,6 +2267,7 @@ static noinline struct module *load_module(void __user *umod, cleanup: kobject_del(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj); + ftrace_release(mod->module_core, mod->core_size); free_unload: module_unload_free(mod); module_free(mod, mod->module_init); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8affb6d..eadd0ea 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -294,13 +294,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node) static void ftrace_free_rec(struct dyn_ftrace *rec) { - /* no locking, only called from kstop_machine */ - rec->ip = (unsigned long)ftrace_free_records; ftrace_free_records = rec; rec->flags |= FTRACE_FL_FREE; } +void ftrace_release(void *start, unsigned long size) +{ + struct dyn_ftrace *rec; + struct ftrace_page *pg; + unsigned long s = (unsigned long)start; + unsigned long e = s + size; + int i; + + if (!start) + return; + + /* No interrupt should call this */ + spin_lock(&ftrace_lock); + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + + if ((rec->ip >= s) && (rec->ip < e)) + ftrace_free_rec(rec); + } + } + spin_unlock(&ftrace_lock); + +} + static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) { struct dyn_ftrace *rec; @@ -1527,7 +1551,9 @@ static int ftrace_convert_nops(unsigned long *start, p = start; while (p < end) { addr = ftrace_call_adjust(*p++); + spin_lock(&ftrace_lock); ftrace_record_ip(addr); + spin_unlock(&ftrace_lock); ftrace_shutdown_replenish(); } @@ -1541,6 +1567,8 @@ static int ftrace_convert_nops(unsigned long *start, void ftrace_init_module(unsigned long *start, unsigned long *end) { + if (start == end) + return; ftrace_convert_nops(start, end); } -- cgit v1.1 From 2e2ca155cd2213b4f398031180fb3d399d5b7db9 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 1 Aug 2008 12:26:40 -0400 Subject: ftrace: new continue entry - separate out from trace_entry Some tracers will need to work with more than one entry. In order to do this the trace_entry structure was split into two fields. One for the start of all entries, and one to continue an existing entry. The trace_entry structure now has a "field" entry that consists of the previous content of the trace_entry, and a "cont" entry that is just a string buffer the size of the "field" entry. Thanks to Andrew Morton for suggesting this idea. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 267 +++++++++++++++++++++-------------------- kernel/trace/trace.h | 17 ++- kernel/trace/trace_mmiotrace.c | 12 +- 3 files changed, 160 insertions(+), 136 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8f3fb3d..76dfe6d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -817,10 +817,11 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) pc = preempt_count(); - entry->preempt_count = pc & 0xff; - entry->pid = (tsk) ? tsk->pid : 0; - entry->t = ftrace_now(raw_smp_processor_id()); - entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | + entry->field.preempt_count = pc & 0xff; + entry->field.pid = (tsk) ? tsk->pid : 0; + entry->field.t = ftrace_now(raw_smp_processor_id()); + entry->field.flags = + (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); @@ -835,11 +836,11 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, raw_local_irq_save(irq_flags); __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, flags); - entry->type = TRACE_FN; - entry->fn.ip = ip; - entry->fn.parent_ip = parent_ip; + entry->type = TRACE_FN; + entry->field.fn.ip = ip; + entry->field.fn.parent_ip = parent_ip; __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); } @@ -862,10 +863,10 @@ void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, raw_local_irq_save(irq_flags); __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_RW; - entry->mmiorw = *rw; + entry->type = TRACE_MMIO_RW; + entry->field.mmiorw = *rw; __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -882,10 +883,10 @@ void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, raw_local_irq_save(irq_flags); __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_MAP; - entry->mmiomap = *map; + entry->type = TRACE_MMIO_MAP; + entry->field.mmiomap = *map; __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -909,12 +910,12 @@ void __trace_stack(struct trace_array *tr, tracing_generic_entry_update(entry, flags); entry->type = TRACE_STACK; - memset(&entry->stack, 0, sizeof(entry->stack)); + memset(&entry->field.stack, 0, sizeof(entry->field.stack)); trace.nr_entries = 0; trace.max_entries = FTRACE_STACK_ENTRIES; trace.skip = skip; - trace.entries = entry->stack.caller; + trace.entries = entry->field.stack.caller; save_stack_trace(&trace); } @@ -930,12 +931,12 @@ __trace_special(void *__tr, void *__data, raw_local_irq_save(irq_flags); __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, 0); - entry->type = TRACE_SPECIAL; - entry->special.arg1 = arg1; - entry->special.arg2 = arg2; - entry->special.arg3 = arg3; + entry->type = TRACE_SPECIAL; + entry->field.special.arg1 = arg1; + entry->field.special.arg2 = arg2; + entry->field.special.arg3 = arg3; __trace_stack(tr, data, irq_flags, 4); __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -955,15 +956,15 @@ tracing_sched_switch_trace(struct trace_array *tr, raw_local_irq_save(irq_flags); __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, flags); - entry->type = TRACE_CTX; - entry->ctx.prev_pid = prev->pid; - entry->ctx.prev_prio = prev->prio; - entry->ctx.prev_state = prev->state; - entry->ctx.next_pid = next->pid; - entry->ctx.next_prio = next->prio; - entry->ctx.next_state = next->state; + entry->type = TRACE_CTX; + entry->field.ctx.prev_pid = prev->pid; + entry->field.ctx.prev_prio = prev->prio; + entry->field.ctx.prev_state = prev->state; + entry->field.ctx.next_pid = next->pid; + entry->field.ctx.next_prio = next->prio; + entry->field.ctx.next_state = next->state; __trace_stack(tr, data, flags, 5); __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -984,12 +985,12 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry = tracing_get_trace_entry(tr, data); tracing_generic_entry_update(entry, flags); entry->type = TRACE_WAKE; - entry->ctx.prev_pid = curr->pid; - entry->ctx.prev_prio = curr->prio; - entry->ctx.prev_state = curr->state; - entry->ctx.next_pid = wakee->pid; - entry->ctx.next_prio = wakee->prio; - entry->ctx.next_state = wakee->state; + entry->field.ctx.prev_pid = curr->pid; + entry->field.ctx.prev_prio = curr->prio; + entry->field.ctx.prev_state = curr->state; + entry->field.ctx.next_pid = wakee->pid; + entry->field.ctx.next_prio = wakee->prio; + entry->field.ctx.next_state = wakee->state; __trace_stack(tr, data, flags, 6); __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -1118,7 +1119,7 @@ find_next_entry(struct trace_iterator *iter, int *ent_cpu) /* * Pick the entry with the smallest timestamp: */ - if (ent && (!next || ent->t < next->t)) { + if (ent && (!next || ent->field.t < next->field.t)) { next = ent; next_cpu = cpu; } @@ -1422,19 +1423,20 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) static void lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { + struct trace_field *field = &entry->field; int hardirq, softirq; char *comm; - comm = trace_find_cmdline(entry->pid); + comm = trace_find_cmdline(field->pid); - trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); + trace_seq_printf(s, "%8.8s-%-5d ", comm, field->pid); trace_seq_printf(s, "%d", cpu); trace_seq_printf(s, "%c%c", - (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', - ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); + (field->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', + ((field->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); - hardirq = entry->flags & TRACE_FLAG_HARDIRQ; - softirq = entry->flags & TRACE_FLAG_SOFTIRQ; + hardirq = field->flags & TRACE_FLAG_HARDIRQ; + softirq = field->flags & TRACE_FLAG_SOFTIRQ; if (hardirq && softirq) { trace_seq_putc(s, 'H'); } else { @@ -1448,8 +1450,8 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) } } - if (entry->preempt_count) - trace_seq_printf(s, "%x", entry->preempt_count); + if (field->preempt_count) + trace_seq_printf(s, "%x", field->preempt_count); else trace_seq_puts(s, "."); } @@ -1479,6 +1481,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) struct trace_entry *next_entry = find_next_entry(iter, NULL); unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); struct trace_entry *entry = iter->ent; + struct trace_field *field = &entry->field; unsigned long abs_usecs; unsigned long rel_usecs; char *comm; @@ -1488,17 +1491,17 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) if (!next_entry) next_entry = entry; - rel_usecs = ns2usecs(next_entry->t - entry->t); - abs_usecs = ns2usecs(entry->t - iter->tr->time_start); + rel_usecs = ns2usecs(next_entry->field.t - entry->field.t); + abs_usecs = ns2usecs(entry->field.t - iter->tr->time_start); if (verbose) { - comm = trace_find_cmdline(entry->pid); + comm = trace_find_cmdline(field->pid); trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" " %ld.%03ldms (+%ld.%03ldms): ", comm, - entry->pid, cpu, entry->flags, - entry->preempt_count, trace_idx, - ns2usecs(entry->t), + field->pid, cpu, field->flags, + field->preempt_count, trace_idx, + ns2usecs(field->t), abs_usecs/1000, abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); @@ -1508,41 +1511,42 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) } switch (entry->type) { case TRACE_FN: - seq_print_ip_sym(s, entry->fn.ip, sym_flags); + seq_print_ip_sym(s, field->fn.ip, sym_flags); trace_seq_puts(s, " ("); - if (kretprobed(entry->fn.parent_ip)) + if (kretprobed(field->fn.parent_ip)) trace_seq_puts(s, KRETPROBE_MSG); else - seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); + seq_print_ip_sym(s, field->fn.parent_ip, sym_flags); trace_seq_puts(s, ")\n"); break; case TRACE_CTX: case TRACE_WAKE: - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + T = field->ctx.next_state < sizeof(state_to_char) ? + state_to_char[field->ctx.next_state] : 'X'; - state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0; + state = field->ctx.prev_state ? + __ffs(field->ctx.prev_state) + 1 : 0; S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X'; - comm = trace_find_cmdline(entry->ctx.next_pid); + comm = trace_find_cmdline(field->ctx.next_pid); trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + field->ctx.prev_pid, + field->ctx.prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - entry->ctx.next_pid, - entry->ctx.next_prio, + field->ctx.next_pid, + field->ctx.next_prio, T, comm); break; case TRACE_SPECIAL: trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->special.arg1, + field->special.arg2, + field->special.arg3); break; case TRACE_STACK: for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) trace_seq_puts(s, " <= "); - seq_print_ip_sym(s, entry->stack.caller[i], sym_flags); + seq_print_ip_sym(s, field->stack.caller[i], sym_flags); } trace_seq_puts(s, "\n"); break; @@ -1557,6 +1561,7 @@ static int print_trace_fmt(struct trace_iterator *iter) struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); struct trace_entry *entry; + struct trace_field *field; unsigned long usec_rem; unsigned long long t; unsigned long secs; @@ -1566,14 +1571,15 @@ static int print_trace_fmt(struct trace_iterator *iter) int i; entry = iter->ent; + field = &entry->field; - comm = trace_find_cmdline(iter->ent->pid); + comm = trace_find_cmdline(iter->ent->field.pid); - t = ns2usecs(entry->t); + t = ns2usecs(field->t); usec_rem = do_div(t, 1000000ULL); secs = (unsigned long)t; - ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); + ret = trace_seq_printf(s, "%16s-%-5d ", comm, field->pid); if (!ret) return 0; ret = trace_seq_printf(s, "[%02d] ", iter->cpu); @@ -1585,18 +1591,19 @@ static int print_trace_fmt(struct trace_iterator *iter) switch (entry->type) { case TRACE_FN: - ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); + ret = seq_print_ip_sym(s, field->fn.ip, sym_flags); if (!ret) return 0; if ((sym_flags & TRACE_ITER_PRINT_PARENT) && - entry->fn.parent_ip) { + field->fn.parent_ip) { ret = trace_seq_printf(s, " <-"); if (!ret) return 0; - if (kretprobed(entry->fn.parent_ip)) + if (kretprobed(field->fn.parent_ip)) ret = trace_seq_puts(s, KRETPROBE_MSG); else - ret = seq_print_ip_sym(s, entry->fn.parent_ip, + ret = seq_print_ip_sym(s, + field->fn.parent_ip, sym_flags); if (!ret) return 0; @@ -1607,26 +1614,26 @@ static int print_trace_fmt(struct trace_iterator *iter) break; case TRACE_CTX: case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + S = field->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[field->ctx.prev_state] : 'X'; + T = field->ctx.next_state < sizeof(state_to_char) ? + state_to_char[field->ctx.next_state] : 'X'; ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + field->ctx.prev_pid, + field->ctx.prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - entry->ctx.next_pid, - entry->ctx.next_prio, + field->ctx.next_pid, + field->ctx.next_prio, T); if (!ret) return 0; break; case TRACE_SPECIAL: ret = trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->special.arg1, + field->special.arg2, + field->special.arg3); if (!ret) return 0; break; @@ -1637,7 +1644,7 @@ static int print_trace_fmt(struct trace_iterator *iter) if (!ret) return 0; } - ret = seq_print_ip_sym(s, entry->stack.caller[i], + ret = seq_print_ip_sym(s, field->stack.caller[i], sym_flags); if (!ret) return 0; @@ -1654,37 +1661,40 @@ static int print_raw_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; + struct trace_field *field; int ret; int S, T; entry = iter->ent; + field = &entry->field; ret = trace_seq_printf(s, "%d %d %llu ", - entry->pid, iter->cpu, entry->t); + field->pid, iter->cpu, field->t); if (!ret) return 0; switch (entry->type) { case TRACE_FN: ret = trace_seq_printf(s, "%x %x\n", - entry->fn.ip, entry->fn.parent_ip); + field->fn.ip, + field->fn.parent_ip); if (!ret) return 0; break; case TRACE_CTX: case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + S = field->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[field->ctx.prev_state] : 'X'; + T = field->ctx.next_state < sizeof(state_to_char) ? + state_to_char[field->ctx.next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; ret = trace_seq_printf(s, "%d %d %c %d %d %c\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + field->ctx.prev_pid, + field->ctx.prev_prio, S, - entry->ctx.next_pid, - entry->ctx.next_prio, + field->ctx.next_pid, + field->ctx.next_prio, T); if (!ret) return 0; @@ -1692,9 +1702,9 @@ static int print_raw_fmt(struct trace_iterator *iter) case TRACE_SPECIAL: case TRACE_STACK: ret = trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->special.arg1, + field->special.arg2, + field->special.arg3); if (!ret) return 0; break; @@ -1719,40 +1729,41 @@ static int print_hex_fmt(struct trace_iterator *iter) struct trace_seq *s = &iter->seq; unsigned char newline = '\n'; struct trace_entry *entry; + struct trace_field *field; int S, T; entry = iter->ent; + field = &entry->field; - SEQ_PUT_HEX_FIELD_RET(s, entry->pid); + SEQ_PUT_HEX_FIELD_RET(s, field->pid); SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); - SEQ_PUT_HEX_FIELD_RET(s, entry->t); + SEQ_PUT_HEX_FIELD_RET(s, field->t); switch (entry->type) { case TRACE_FN: - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip); - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + SEQ_PUT_HEX_FIELD_RET(s, field->fn.ip); + SEQ_PUT_HEX_FIELD_RET(s, field->fn.parent_ip); break; case TRACE_CTX: case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + S = field->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[field->ctx.prev_state] : 'X'; + T = field->ctx.next_state < sizeof(state_to_char) ? + state_to_char[field->ctx.next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio); + SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_prio); SEQ_PUT_HEX_FIELD_RET(s, S); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio); - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_prio); SEQ_PUT_HEX_FIELD_RET(s, T); break; case TRACE_SPECIAL: case TRACE_STACK: - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1); - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2); - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3); + SEQ_PUT_HEX_FIELD_RET(s, field->special.arg1); + SEQ_PUT_HEX_FIELD_RET(s, field->special.arg2); + SEQ_PUT_HEX_FIELD_RET(s, field->special.arg3); break; } SEQ_PUT_FIELD_RET(s, newline); @@ -1764,31 +1775,33 @@ static int print_bin_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; + struct trace_field *field; entry = iter->ent; + field = &entry->field; - SEQ_PUT_FIELD_RET(s, entry->pid); - SEQ_PUT_FIELD_RET(s, entry->cpu); - SEQ_PUT_FIELD_RET(s, entry->t); + SEQ_PUT_FIELD_RET(s, field->pid); + SEQ_PUT_FIELD_RET(s, field->cpu); + SEQ_PUT_FIELD_RET(s, field->t); switch (entry->type) { case TRACE_FN: - SEQ_PUT_FIELD_RET(s, entry->fn.ip); - SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip); + SEQ_PUT_FIELD_RET(s, field->fn.ip); + SEQ_PUT_FIELD_RET(s, field->fn.parent_ip); break; case TRACE_CTX: - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid); - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio); - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_state); + SEQ_PUT_FIELD_RET(s, field->ctx.prev_pid); + SEQ_PUT_FIELD_RET(s, field->ctx.prev_prio); + SEQ_PUT_FIELD_RET(s, field->ctx.prev_state); + SEQ_PUT_FIELD_RET(s, field->ctx.next_pid); + SEQ_PUT_FIELD_RET(s, field->ctx.next_prio); + SEQ_PUT_FIELD_RET(s, field->ctx.next_state); break; case TRACE_SPECIAL: case TRACE_STACK: - SEQ_PUT_FIELD_RET(s, entry->special.arg1); - SEQ_PUT_FIELD_RET(s, entry->special.arg2); - SEQ_PUT_FIELD_RET(s, entry->special.arg3); + SEQ_PUT_FIELD_RET(s, field->special.arg1); + SEQ_PUT_FIELD_RET(s, field->special.arg2); + SEQ_PUT_FIELD_RET(s, field->special.arg3); break; } return 1; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f69f867..6ddd6a6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -61,13 +61,12 @@ struct stack_entry { }; /* - * The trace entry - the most basic unit of tracing. This is what + * The trace field - the most basic unit of tracing. This is what * is printed in the end as a single line in the trace output, such as: * * bash-15816 [01] 235.197585: idle_cpu <- irq_enter */ -struct trace_entry { - char type; +struct trace_field { char cpu; char flags; char preempt_count; @@ -83,6 +82,18 @@ struct trace_entry { }; }; +struct trace_field_cont { + char buf[sizeof(struct trace_field)]; +}; + +struct trace_entry { + char type; + union { + struct trace_field field; + struct trace_field_cont cont; + }; +}; + #define TRACE_ENTRY_SIZE sizeof(struct trace_entry) /* diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index b13dc19..9b7a936 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -174,14 +174,14 @@ print_out: static int mmio_print_rw(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_rw *rw = &entry->mmiorw; + struct mmiotrace_rw *rw = &entry->field.mmiorw; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->t); + unsigned long long t = ns2usecs(entry->field.t); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; - switch (entry->mmiorw.opcode) { + switch (entry->field.mmiorw.opcode) { case MMIO_READ: ret = trace_seq_printf(s, "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", @@ -216,14 +216,14 @@ static int mmio_print_rw(struct trace_iterator *iter) static int mmio_print_map(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_map *m = &entry->mmiomap; + struct mmiotrace_map *m = &entry->field.mmiomap; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->t); + unsigned long long t = ns2usecs(entry->field.t); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; - switch (entry->mmiorw.opcode) { + switch (entry->field.mmiorw.opcode) { case MMIO_PROBE: ret = trace_seq_printf(s, "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", -- cgit v1.1 From dd0e545f061f90099a3dcc13aa77e29c6295cf23 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 1 Aug 2008 12:26:41 -0400 Subject: ftrace: printk formatting infrastructure This patch adds a feature that can help kernel developers debug their code using ftrace. int ftrace_printk(const char *fmt, ...); This records into the ftrace buffer using printf formatting. The entry size in the buffers are still a fixed length. A new type has been added that allows for more entries to be used for a single recording. The start of the print is still the same as the other entries. It returns the number of characters written to the ftrace buffer. For example: Having a module with the following code: static int __init ftrace_print_test(void) { ftrace_printk("jiffies are %ld\n", jiffies); return 0; } Gives me: insmod-5441 3...1 7569us : ftrace_print_test: jiffies are 4296626666 for the latency_trace file and: insmod-5441 [03] 1959.370498: ftrace_print_test jiffies are 4296626666 for the trace file. Note: Only the infrastructure should go into the kernel. It is to help facilitate debugging for other kernel developers. Calls to ftrace_printk is not intended to be left in the kernel, and should be frowned upon just like scattering printks around in the code. But having this easily at your fingertips helps the debugging go faster and bugs be solved quicker. Maybe later on, we can hook this with markers and have their printf format be sucked into ftrace output. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 273 +++++++++++++++++++++++++++++++++++++----- kernel/trace/trace.h | 11 ++ kernel/trace/trace_selftest.c | 11 +- 3 files changed, 262 insertions(+), 33 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 76dfe6d..a917bea 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -197,12 +197,14 @@ unsigned long nsecs_to_usecs(unsigned long nsecs) * NEED_RESCED - reschedule is requested * HARDIRQ - inside an interrupt handler * SOFTIRQ - inside a softirq handler + * CONT - multiple entries hold the trace item */ enum trace_flag_type { TRACE_FLAG_IRQS_OFF = 0x01, TRACE_FLAG_NEED_RESCHED = 0x02, TRACE_FLAG_HARDIRQ = 0x04, TRACE_FLAG_SOFTIRQ = 0x08, + TRACE_FLAG_CONT = 0x10, }; /* @@ -1074,6 +1076,7 @@ enum trace_file_type { TRACE_FILE_LAT_FMT = 1, }; +/* Return the current entry. */ static struct trace_entry * trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, struct trace_iterator *iter, int cpu) @@ -1104,8 +1107,58 @@ trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, return &array[iter->next_page_idx[cpu]]; } +/* Increment the index counter of an iterator by one */ +static void trace_iterator_increment(struct trace_iterator *iter, int cpu) +{ + iter->idx++; + iter->next_idx[cpu]++; + iter->next_page_idx[cpu]++; + + if (iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE) { + struct trace_array_cpu *data = iter->tr->data[cpu]; + + iter->next_page_idx[cpu] = 0; + iter->next_page[cpu] = + trace_next_list(data, iter->next_page[cpu]); + } +} + static struct trace_entry * -find_next_entry(struct trace_iterator *iter, int *ent_cpu) +trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data, + struct trace_iterator *iter, int cpu) +{ + struct list_head *next_page; + struct trace_entry *ent; + int idx, next_idx, next_page_idx; + + ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + + if (likely(!ent || ent->type != TRACE_CONT)) + return ent; + + /* save the iterator details */ + idx = iter->idx; + next_idx = iter->next_idx[cpu]; + next_page_idx = iter->next_page_idx[cpu]; + next_page = iter->next_page[cpu]; + + /* find a real entry */ + do { + trace_iterator_increment(iter, cpu); + ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + } while (ent && ent->type != TRACE_CONT); + + /* reset the iterator */ + iter->idx = idx; + iter->next_idx[cpu] = next_idx; + iter->next_page_idx[cpu] = next_page_idx; + iter->next_page[cpu] = next_page; + + return ent; +} + +static struct trace_entry * +__find_next_entry(struct trace_iterator *iter, int *ent_cpu, int inc) { struct trace_array *tr = iter->tr; struct trace_entry *ent, *next = NULL; @@ -1115,7 +1168,23 @@ find_next_entry(struct trace_iterator *iter, int *ent_cpu) for_each_tracing_cpu(cpu) { if (!head_page(tr->data[cpu])) continue; + ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + + if (ent && ent->type == TRACE_CONT) { + struct trace_array_cpu *data = tr->data[cpu]; + + if (!inc) + ent = trace_entry_next(tr, data, iter, cpu); + else { + while (ent && ent->type == TRACE_CONT) { + trace_iterator_increment(iter, cpu); + ent = trace_entry_idx(tr, tr->data[cpu], + iter, cpu); + } + } + } + /* * Pick the entry with the smallest timestamp: */ @@ -1131,25 +1200,39 @@ find_next_entry(struct trace_iterator *iter, int *ent_cpu) return next; } -static void trace_iterator_increment(struct trace_iterator *iter) +/* Find the next real entry, without updating the iterator itself */ +static struct trace_entry * +find_next_entry(struct trace_iterator *iter, int *ent_cpu) { - iter->idx++; - iter->next_idx[iter->cpu]++; - iter->next_page_idx[iter->cpu]++; + return __find_next_entry(iter, ent_cpu, 0); +} + +/* Find the next real entry, and increment the iterator to the next entry */ +static void *find_next_entry_inc(struct trace_iterator *iter) +{ + struct trace_entry *next; + int next_cpu = -1; - if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { - struct trace_array_cpu *data = iter->tr->data[iter->cpu]; + next = __find_next_entry(iter, &next_cpu, 1); - iter->next_page_idx[iter->cpu] = 0; - iter->next_page[iter->cpu] = - trace_next_list(data, iter->next_page[iter->cpu]); - } + iter->prev_ent = iter->ent; + iter->prev_cpu = iter->cpu; + + iter->ent = next; + iter->cpu = next_cpu; + + if (next) + trace_iterator_increment(iter, iter->cpu); + + return next ? iter : NULL; } static void trace_consume(struct trace_iterator *iter) { struct trace_array_cpu *data = iter->tr->data[iter->cpu]; + struct trace_entry *ent; + again: data->trace_tail_idx++; if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { data->trace_tail = trace_next_page(data, data->trace_tail); @@ -1160,25 +1243,11 @@ static void trace_consume(struct trace_iterator *iter) if (data->trace_head == data->trace_tail && data->trace_head_idx == data->trace_tail_idx) data->trace_idx = 0; -} - -static void *find_next_entry_inc(struct trace_iterator *iter) -{ - struct trace_entry *next; - int next_cpu = -1; - - next = find_next_entry(iter, &next_cpu); - - iter->prev_ent = iter->ent; - iter->prev_cpu = iter->cpu; - - iter->ent = next; - iter->cpu = next_cpu; - - if (next) - trace_iterator_increment(iter); - return next ? iter : NULL; + ent = trace_entry_idx(iter->tr, iter->tr->data[iter->cpu], + iter, iter->cpu); + if (ent && ent->type == TRACE_CONT) + goto again; } static void *s_next(struct seq_file *m, void *v, loff_t *pos) @@ -1473,6 +1542,26 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; +static void +trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) +{ + struct trace_array *tr = iter->tr; + struct trace_array_cpu *data = tr->data[iter->cpu]; + struct trace_entry *ent; + + ent = trace_entry_idx(tr, data, iter, iter->cpu); + if (!ent || ent->type != TRACE_CONT) { + trace_seq_putc(s, '\n'); + return; + } + + do { + trace_seq_printf(s, "%s", ent->cont.buf); + trace_iterator_increment(iter, iter->cpu); + ent = trace_entry_idx(tr, data, iter, iter->cpu); + } while (ent && ent->type == TRACE_CONT); +} + static int print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { @@ -1491,6 +1580,10 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) if (!next_entry) next_entry = entry; + + if (entry->type == TRACE_CONT) + return 1; + rel_usecs = ns2usecs(next_entry->field.t - entry->field.t); abs_usecs = ns2usecs(entry->field.t - iter->tr->time_start); @@ -1550,6 +1643,12 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) } trace_seq_puts(s, "\n"); break; + case TRACE_PRINT: + seq_print_ip_sym(s, field->print.ip, sym_flags); + trace_seq_printf(s, ": %s", field->print.buf); + if (field->flags && TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } @@ -1571,6 +1670,10 @@ static int print_trace_fmt(struct trace_iterator *iter) int i; entry = iter->ent; + + if (entry->type == TRACE_CONT) + return 1; + field = &entry->field; comm = trace_find_cmdline(iter->ent->field.pid); @@ -1653,6 +1756,12 @@ static int print_trace_fmt(struct trace_iterator *iter) if (!ret) return 0; break; + case TRACE_PRINT: + seq_print_ip_sym(s, field->print.ip, sym_flags); + trace_seq_printf(s, ": %s", field->print.buf); + if (field->flags && TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; } return 1; } @@ -1666,6 +1775,10 @@ static int print_raw_fmt(struct trace_iterator *iter) int S, T; entry = iter->ent; + + if (entry->type == TRACE_CONT) + return 1; + field = &entry->field; ret = trace_seq_printf(s, "%d %d %llu ", @@ -1708,6 +1821,12 @@ static int print_raw_fmt(struct trace_iterator *iter) if (!ret) return 0; break; + case TRACE_PRINT: + trace_seq_printf(s, "# %lx %s", + field->print.ip, field->print.buf); + if (field->flags && TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; } return 1; } @@ -1733,6 +1852,10 @@ static int print_hex_fmt(struct trace_iterator *iter) int S, T; entry = iter->ent; + + if (entry->type == TRACE_CONT) + return 1; + field = &entry->field; SEQ_PUT_HEX_FIELD_RET(s, field->pid); @@ -1778,6 +1901,10 @@ static int print_bin_fmt(struct trace_iterator *iter) struct trace_field *field; entry = iter->ent; + + if (entry->type == TRACE_CONT) + return 1; + field = &entry->field; SEQ_PUT_FIELD_RET(s, field->pid); @@ -2943,6 +3070,94 @@ static __init void tracer_init_debugfs(void) #endif } +#define TRACE_BUF_SIZE 1024 +#define TRACE_PRINT_BUF_SIZE \ + (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) +#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) + +/** + * ftrace_printk - printf formatting in the ftrace buffer + * @fmt - the printf format for printing. + * + * Note: __ftrace_printk is an internal function for ftrace_printk and + * the @ip is passed in via the ftrace_printk macro. + * + * This function allows a kernel developer to debug fast path sections + * that printk is not appropriate for. By scattering in various + * printk like tracing in the code, a developer can quickly see + * where problems are occurring. + * + * This is intended as a debugging tool for the developer only. + * Please reframe from leaving ftrace_printks scattered around in + * your code. + */ +int __ftrace_printk(unsigned long ip, const char *fmt, ...) +{ + struct trace_array *tr = &global_trace; + static DEFINE_SPINLOCK(trace_buf_lock); + static char trace_buf[TRACE_BUF_SIZE]; + struct trace_array_cpu *data; + struct trace_entry *entry; + unsigned long flags; + long disabled; + va_list ap; + int cpu, len = 0, write, written = 0; + + if (likely(!ftrace_function_enabled)) + return 0; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (unlikely(disabled != 1 || !ftrace_function_enabled)) + goto out; + + spin_lock(&trace_buf_lock); + va_start(ap, fmt); + len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, ap); + va_end(ap); + + len = min(len, TRACE_BUF_SIZE-1); + trace_buf[len] = 0; + + __raw_spin_lock(&data->lock); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, flags); + entry->type = TRACE_PRINT; + entry->field.print.ip = ip; + + write = min(len, (int)(TRACE_PRINT_BUF_SIZE-1)); + + memcpy(&entry->field.print.buf, trace_buf, write); + entry->field.print.buf[write] = 0; + written = write; + + if (written != len) + entry->field.flags |= TRACE_FLAG_CONT; + + while (written != len) { + entry = tracing_get_trace_entry(tr, data); + + entry->type = TRACE_CONT; + write = min(len - written, (int)(TRACE_CONT_BUF_SIZE-1)); + memcpy(&entry->cont.buf, trace_buf+written, write); + entry->cont.buf[write] = 0; + written += write; + } + __raw_spin_unlock(&data->lock); + + spin_unlock(&trace_buf_lock); + + out: + atomic_dec(&data->disabled); + local_irq_restore(flags); + + return len; +} +EXPORT_SYMBOL_GPL(__ftrace_printk); + static int trace_alloc_page(void) { struct trace_array_cpu *data; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6ddd6a6..50b6d7a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -13,7 +13,9 @@ enum trace_type { TRACE_FN, TRACE_CTX, TRACE_WAKE, + TRACE_CONT, TRACE_STACK, + TRACE_PRINT, TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, @@ -61,6 +63,14 @@ struct stack_entry { }; /* + * ftrace_printk entry: + */ +struct print_entry { + unsigned long ip; + char buf[]; +}; + +/* * The trace field - the most basic unit of tracing. This is what * is printed in the end as a single line in the trace output, such as: * @@ -77,6 +87,7 @@ struct trace_field { struct ctx_switch_entry ctx; struct special_entry special; struct stack_entry stack; + struct print_entry print; struct mmiotrace_rw mmiorw; struct mmiotrace_map mmiomap; }; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 0911b7e..630715b 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -9,7 +9,9 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_FN: case TRACE_CTX: case TRACE_WAKE: + case TRACE_CONT: case TRACE_STACK: + case TRACE_PRINT: case TRACE_SPECIAL: return 1; } @@ -120,11 +122,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, struct trace_array *tr, int (*func)(void)) { - unsigned long count; - int ret; int save_ftrace_enabled = ftrace_enabled; int save_tracer_enabled = tracer_enabled; + unsigned long count; char *func_name; + int ret; /* The ftrace test PASSED */ printk(KERN_CONT "PASSED\n"); @@ -157,6 +159,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* enable tracing */ tr->ctrl = 1; trace->init(tr); + /* Sleep for a 1/10 of a second */ msleep(100); @@ -212,10 +215,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) { - unsigned long count; - int ret; int save_ftrace_enabled = ftrace_enabled; int save_tracer_enabled = tracer_enabled; + unsigned long count; + int ret; /* make sure msleep has been recorded */ msleep(1); -- cgit v1.1 From 2f2c99dba2398ef7d9c21f7c793180a50e68b1f0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 1 Aug 2008 16:45:49 -0400 Subject: ftrace: ftrace_printk doc moved Based on Randy Dunlap's suggestion, the ftrace_printk kernel-doc belongs with the ftrace_printk macro that should be used. Not with the __ftrace_printk internal function. Signed-off-by: Steven Rostedt Acked-by: Randy Dunlap Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a917bea..2597e7e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3075,22 +3075,6 @@ static __init void tracer_init_debugfs(void) (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) #define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) -/** - * ftrace_printk - printf formatting in the ftrace buffer - * @fmt - the printf format for printing. - * - * Note: __ftrace_printk is an internal function for ftrace_printk and - * the @ip is passed in via the ftrace_printk macro. - * - * This function allows a kernel developer to debug fast path sections - * that printk is not appropriate for. By scattering in various - * printk like tracing in the code, a developer can quickly see - * where problems are occurring. - * - * This is intended as a debugging tool for the developer only. - * Please reframe from leaving ftrace_printks scattered around in - * your code. - */ int __ftrace_printk(unsigned long ip, const char *fmt, ...) { struct trace_array *tr = &global_trace; -- cgit v1.1 From 3f5a54e371ca20b119b73704f6c01b71295c1714 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 30 Jul 2008 22:36:46 -0400 Subject: ftrace: dump out ftrace buffers to console on panic At OLS I had a lot of interest to be able to have the ftrace buffers dumped on panic. Usually one would expect to uses kexec and examine the buffers after a new kernel is loaded. But sometimes the resources do not permit kdump and kexec, so having an option to still see the sequence of events up to the crash is very advantageous. This patch adds the option to have the ftrace buffers dumped to the console in the latency_trace format on a panic. When the option is set, the default entries per CPU buffer are lowered to 16384, since the writing to the serial (if that is the console) may take an awful long time otherwise. [ Changes since -v1: Got alpine to send correctly (as well as spell check working). Removed config option. Moved the static variables into ftrace_dump itself. Gave printk a log level. ] Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 174 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2597e7e..97513c8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -22,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -103,8 +105,15 @@ int ftrace_function_enabled; * trace_nr_entries is the number of entries that is allocated * for a buffer. Note, the number of entries is always rounded * to ENTRIES_PER_PAGE. + * + * This number is purposely set to a low number of 16384. + * If the dump on oops happens, it will be much appreciated + * to not have to wait for all that output. Anyway this can be + * boot time and run time configurable. */ -static unsigned long trace_nr_entries = 65536UL; +#define TRACE_ENTRIES_DEFAULT 16384UL + +static unsigned long trace_nr_entries = TRACE_ENTRIES_DEFAULT; /* trace_types holds a link list of available tracers. */ static struct tracer *trace_types __read_mostly; @@ -3142,6 +3151,165 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) } EXPORT_SYMBOL_GPL(__ftrace_printk); +static int trace_panic_handler(struct notifier_block *this, + unsigned long event, void *unused) +{ + ftrace_dump(); + return NOTIFY_OK; +} + +static struct notifier_block trace_panic_notifier = { + .notifier_call = trace_panic_handler, + .next = NULL, + .priority = 150 /* priority: INT_MAX >= x >= 0 */ +}; + +static int trace_die_handler(struct notifier_block *self, + unsigned long val, + void *data) +{ + switch (val) { + case DIE_OOPS: + ftrace_dump(); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block trace_die_notifier = { + .notifier_call = trace_die_handler, + .priority = 200 +}; + +/* + * printk is set to max of 1024, we really don't need it that big. + * Nothing should be printing 1000 characters anyway. + */ +#define TRACE_MAX_PRINT 1000 + +/* + * Define here KERN_TRACE so that we have one place to modify + * it if we decide to change what log level the ftrace dump + * should be at. + */ +#define KERN_TRACE KERN_INFO + +static void +trace_printk_seq(struct trace_seq *s) +{ + /* Probably should print a warning here. */ + if (s->len >= 1000) + s->len = 1000; + + /* should be zero ended, but we are paranoid. */ + s->buffer[s->len] = 0; + + printk(KERN_TRACE "%s", s->buffer); + + trace_seq_reset(s); +} + + +void ftrace_dump(void) +{ + static DEFINE_SPINLOCK(ftrace_dump_lock); + /* use static because iter can be a bit big for the stack */ + static struct trace_iterator iter; + struct trace_array_cpu *data; + static cpumask_t mask; + static int dump_ran; + unsigned long flags; + int cnt = 0; + int cpu; + + /* only one dump */ + spin_lock_irqsave(&ftrace_dump_lock, flags); + if (dump_ran) + goto out; + + dump_ran = 1; + + /* No turning back! */ + ftrace_kill_atomic(); + + printk(KERN_TRACE "Dumping ftrace buffer:\n"); + + iter.tr = &global_trace; + iter.trace = current_trace; + + /* + * We need to stop all tracing on all CPUS to read the + * the next buffer. This is a bit expensive, but is + * not done often. We fill all what we can read, + * and then release the locks again. + */ + + cpus_clear(mask); + + for_each_tracing_cpu(cpu) { + data = iter.tr->data[cpu]; + + if (!head_page(data) || !data->trace_idx) + continue; + + atomic_inc(&data->disabled); + cpu_set(cpu, mask); + } + + for_each_cpu_mask(cpu, mask) { + data = iter.tr->data[cpu]; + __raw_spin_lock(&data->lock); + + if (data->overrun > iter.last_overrun[cpu]) + iter.overrun[cpu] += + data->overrun - iter.last_overrun[cpu]; + iter.last_overrun[cpu] = data->overrun; + } + + while (!trace_empty(&iter)) { + + if (!cnt) + printk(KERN_TRACE "---------------------------------\n"); + + cnt++; + + /* reset all but tr, trace, and overruns */ + memset(&iter.seq, 0, + sizeof(struct trace_iterator) - + offsetof(struct trace_iterator, seq)); + iter.iter_flags |= TRACE_FILE_LAT_FMT; + iter.pos = -1; + + if (find_next_entry_inc(&iter) != NULL) { + print_trace_line(&iter); + trace_consume(&iter); + } + + trace_printk_seq(&iter.seq); + } + + if (!cnt) + printk(KERN_TRACE " (ftrace buffer empty)\n"); + else + printk(KERN_TRACE "---------------------------------\n"); + + for_each_cpu_mask(cpu, mask) { + data = iter.tr->data[cpu]; + __raw_spin_unlock(&data->lock); + } + + for_each_cpu_mask(cpu, mask) { + data = iter.tr->data[cpu]; + atomic_dec(&data->disabled); + } + + + out: + spin_unlock_irqrestore(&ftrace_dump_lock, flags); +} + static int trace_alloc_page(void) { struct trace_array_cpu *data; @@ -3338,6 +3506,11 @@ __init static int tracer_alloc_buffers(void) global_trace.ctrl = tracer_enabled; tracing_disabled = 0; + atomic_notifier_chain_register(&panic_notifier_list, + &trace_panic_notifier); + + register_die_notifier(&trace_die_notifier); + return 0; free_buffers: -- cgit v1.1 From 98a983aad2e5b3dc83a8a761675445cdd8f3e6bd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Fri, 15 Aug 2008 21:08:22 +0200 Subject: ftrace: fix some mistakes in error messages This patch fixes some mistakes on the tracer in warning messages when debugfs fails to create tracing files. Signed-off-by: Frederic Weisbecker Cc: srostedt@redhat.com Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 97513c8..896e59f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3030,12 +3030,12 @@ static __init void tracer_init_debugfs(void) entry = debugfs_create_file("available_tracers", 0444, d_tracer, &global_trace, &show_traces_fops); if (!entry) - pr_warning("Could not create debugfs 'trace' entry\n"); + pr_warning("Could not create debugfs 'available_tracers' entry\n"); entry = debugfs_create_file("current_tracer", 0444, d_tracer, &global_trace, &set_tracer_fops); if (!entry) - pr_warning("Could not create debugfs 'trace' entry\n"); + pr_warning("Could not create debugfs 'current_tracer' entry\n"); entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, &tracing_max_latency, @@ -3048,7 +3048,7 @@ static __init void tracer_init_debugfs(void) &tracing_thresh, &tracing_max_lat_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'tracing_thresh' entry\n"); entry = debugfs_create_file("README", 0644, d_tracer, NULL, &tracing_readme_fops); if (!entry) @@ -3058,13 +3058,13 @@ static __init void tracer_init_debugfs(void) NULL, &tracing_pipe_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'trace_pipe' entry\n"); entry = debugfs_create_file("trace_entries", 0644, d_tracer, &global_trace, &tracing_entries_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'trace_entries' entry\n"); #ifdef CONFIG_DYNAMIC_FTRACE entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, -- cgit v1.1 From 00fd61aee10533e003f2f00ab7163207660a4051 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 15 Aug 2008 21:40:04 -0400 Subject: ftrace: do not init module on ftrace disabled If one of the self tests of ftrace has disabled the function tracer, do not run the code to convert the mcount calls in modules. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index eadd0ea..11d94f2 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -307,7 +307,7 @@ void ftrace_release(void *start, unsigned long size) unsigned long e = s + size; int i; - if (!start) + if (ftrace_disabled || !start) return; /* No interrupt should call this */ @@ -1567,7 +1567,7 @@ static int ftrace_convert_nops(unsigned long *start, void ftrace_init_module(unsigned long *start, unsigned long *end) { - if (start == end) + if (ftrace_disabled || start == end) return; ftrace_convert_nops(start, end); } -- cgit v1.1 From 99ecdc43bc17faf5fa571db8569df171ecd0e5b8 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 15 Aug 2008 21:40:05 -0400 Subject: ftrace: add necessary locking for ftrace records The new design of pre-recorded mcounts and updating the code outside of kstop_machine has changed the way the records themselves are protected. This patch uses the ftrace_lock to protect the records. Note, the lock still does not need to be taken within calls that are only called via kstop_machine, since the that code can not run while the spin lock is held. Also removed the hash_lock needed for the daemon when MCOUNT_RECORD is configured. Also did a slight cleanup of an unused variable. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 11d94f2..43665ad 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -81,7 +81,7 @@ void clear_ftrace_function(void) static int __register_ftrace_function(struct ftrace_ops *ops) { - /* Should never be called by interrupts */ + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); ops->next = ftrace_list; @@ -115,6 +115,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) struct ftrace_ops **p; int ret = 0; + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); /* @@ -153,6 +154,21 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) #ifdef CONFIG_DYNAMIC_FTRACE +#ifndef CONFIG_FTRACE_MCOUNT_RECORD +/* + * The hash lock is only needed when the recording of the mcount + * callers are dynamic. That is, by the caller themselves and + * not recorded via the compilation. + */ +static DEFINE_SPINLOCK(ftrace_hash_lock); +#define ftrace_hash_lock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) +#define ftrace_hash_unlock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) +#else +/* This is protected via the ftrace_lock with MCOUNT_RECORD. */ +#define ftrace_hash_lock(flags) do { (void)flags; } while (0) +#define ftrace_hash_unlock(flags) do { } while(0) +#endif + static struct task_struct *ftraced_task; enum { @@ -171,7 +187,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); -static DEFINE_SPINLOCK(ftrace_shutdown_lock); static DEFINE_MUTEX(ftraced_lock); static DEFINE_MUTEX(ftrace_regex_lock); @@ -310,7 +325,7 @@ void ftrace_release(void *start, unsigned long size) if (ftrace_disabled || !start) return; - /* No interrupt should call this */ + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); for (pg = ftrace_pages_start; pg; pg = pg->next) { @@ -362,7 +377,6 @@ ftrace_record_ip(unsigned long ip) unsigned long flags; unsigned long key; int resched; - int atomic; int cpu; if (!ftrace_enabled || ftrace_disabled) @@ -392,9 +406,7 @@ ftrace_record_ip(unsigned long ip) if (ftrace_ip_in_hash(ip, key)) goto out; - atomic = irqs_disabled(); - - spin_lock_irqsave(&ftrace_shutdown_lock, flags); + ftrace_hash_lock(flags); /* This ip may have hit the hash before the lock */ if (ftrace_ip_in_hash(ip, key)) @@ -411,7 +423,7 @@ ftrace_record_ip(unsigned long ip) ftraced_trigger = 1; out_unlock: - spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); + ftrace_hash_unlock(flags); out: per_cpu(ftrace_shutdown_disable_cpu, cpu)--; @@ -887,6 +899,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos) (*pos)++; + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); retry: if (iter->idx >= iter->pg->index) { if (iter->pg->next) { @@ -910,6 +924,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) goto retry; } } + spin_unlock(&ftrace_lock); iter->pos = *pos; @@ -1023,8 +1038,8 @@ static void ftrace_filter_reset(int enable) unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; unsigned i; - /* keep kstop machine from running */ - preempt_disable(); + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); if (enable) ftrace_filtered = 0; pg = ftrace_pages_start; @@ -1037,7 +1052,7 @@ static void ftrace_filter_reset(int enable) } pg = pg->next; } - preempt_enable(); + spin_unlock(&ftrace_lock); } static int @@ -1149,8 +1164,8 @@ ftrace_match(unsigned char *buff, int len, int enable) } } - /* keep kstop machine from running */ - preempt_disable(); + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); if (enable) ftrace_filtered = 1; pg = ftrace_pages_start; @@ -1187,7 +1202,7 @@ ftrace_match(unsigned char *buff, int len, int enable) } pg = pg->next; } - preempt_enable(); + spin_unlock(&ftrace_lock); } static ssize_t @@ -1551,6 +1566,7 @@ static int ftrace_convert_nops(unsigned long *start, p = start; while (p < end) { addr = ftrace_call_adjust(*p++); + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); ftrace_record_ip(addr); spin_unlock(&ftrace_lock); -- cgit v1.1 From 2d7da80f7138c4276ef4fa0334be400b805d0fbf Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Mon, 25 Aug 2008 13:08:44 +1000 Subject: ftrace: fix build failure After disabling FTRACE_MCOUNT_RECORD via a patch, a dormant build failure surfaced: kernel/trace/ftrace.c: In function 'ftrace_record_ip': kernel/trace/ftrace.c:416: error: incompatible type for argument 1 of '_spin_lock_irqsave' kernel/trace/ftrace.c:433: error: incompatible type for argument 1 of '_spin_lock_irqsave' Introduced by commit 6dad8e07f4c10b17b038e84d29f3ca41c2e55cd0 ("ftrace: add necessary locking for ftrace records"). Signed-off-by: Stephen Rothwell Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 43665ad..7599abd 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -161,8 +161,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) * not recorded via the compilation. */ static DEFINE_SPINLOCK(ftrace_hash_lock); -#define ftrace_hash_lock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) -#define ftrace_hash_unlock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) +#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) +#define ftrace_hash_unlock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) #else /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ #define ftrace_hash_lock(flags) do { (void)flags; } while (0) -- cgit v1.1 From ac8825ec6d941b6899331b84c7d6bf027c3bb4f1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 25 Aug 2008 08:12:04 +0200 Subject: ftrace: clean up macro usage enclose the argument in parenthesis. (especially since we cast it, which is a high prio operation) Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7599abd..969a83f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -165,7 +165,7 @@ static DEFINE_SPINLOCK(ftrace_hash_lock); #define ftrace_hash_unlock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) #else /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ -#define ftrace_hash_lock(flags) do { (void)flags; } while (0) +#define ftrace_hash_lock(flags) do { (void)(flags); } while (0) #define ftrace_hash_unlock(flags) do { } while(0) #endif -- cgit v1.1 From e5a81b629ea8feb9e7530cfac35cfb41c45facf3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 27 Aug 2008 23:31:01 -0400 Subject: ftrace: add stack tracer This is another tracer using the ftrace infrastructure, that examines at each function call the size of the stack. If the stack use is greater than the previous max it is recorded. You can always see (and set) the max stack size seen. By setting it to zero will start the recording again. The backtrace is also available. For example: # cat /debug/tracing/stack_max_size 1856 # cat /debug/tracing/stack_trace [] stack_trace_call+0x8f/0x101 [] ftrace_call+0x5/0x8 [] clocksource_get_next+0x12/0x48 [] update_wall_time+0x538/0x6d1 [] do_timer+0x23/0xb0 [] tick_do_update_jiffies64+0xd9/0xf1 [] tick_sched_timer+0x4a/0xad [] __run_hrtimer+0x3e/0x75 [] hrtimer_interrupt+0xf1/0x154 [] smp_apic_timer_interrupt+0x71/0x84 [] apic_timer_interrupt+0x2d/0x34 [] finish_task_switch+0x29/0xa0 [] schedule+0x765/0x7be [] schedule_timeout+0x1b/0x90 [] wait_for_common+0xab/0x101 [] wait_for_completion+0x12/0x14 [] blk_execute_rq+0x84/0x99 [] scsi_execute+0xc2/0x105 [] scsi_execute_req+0x57/0x7f [] sr_test_unit_ready+0x3e/0x97 [] sr_media_change+0x43/0x205 [] media_changed+0x48/0x77 [] cdrom_media_changed+0x31/0x37 [] sr_block_media_changed+0x16/0x18 [] check_disk_change+0x1b/0x63 [] cdrom_open+0x7a1/0x806 [] sr_block_open+0x78/0x8d [] do_open+0x90/0x257 [] blkdev_open+0x2d/0x56 [] __dentry_open+0x14d/0x23c [] nameidata_to_filp+0x24/0x38 [] do_filp_open+0x347/0x626 [] do_sys_open+0x47/0xbc [] sys_open+0x23/0x2b [] sysenter_do_call+0x12/0x26 I've tested this on both x86_64 and i386. Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 9 ++ kernel/trace/Makefile | 1 + kernel/trace/trace_stack.c | 254 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 264 insertions(+) create mode 100644 kernel/trace/trace_stack.c (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 14d9505..2a22e46 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -106,6 +106,15 @@ config CONTEXT_SWITCH_TRACER This tracer gets called from the context switch and records all switching of tasks. +config STACK_TRACER + bool "Trace max stack" + depends on HAVE_FTRACE + select FTRACE + select STACKTRACE + help + This tracer records the max stack of the kernel, and displays + it in debugfs/tracing/stack_trace + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FTRACE diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 71d17de..58ec61c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_FTRACE) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o +obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c new file mode 100644 index 0000000..4d1e522 --- /dev/null +++ b/kernel/trace/trace_stack.c @@ -0,0 +1,254 @@ +/* + * Copyright (C) 2008 Steven Rostedt + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "trace.h" + +#define STACK_TRACE_ENTRIES 500 + +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES] = + { [0 ... (STACK_TRACE_ENTRIES-1)] = ULONG_MAX }; +static struct stack_trace max_stack_trace = { + .max_entries = STACK_TRACE_ENTRIES, + .entries = stack_dump_trace, +}; + +static unsigned long max_stack_size; +static raw_spinlock_t max_stack_lock = + (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + +static int stack_trace_disabled __read_mostly; +static DEFINE_PER_CPU(int, trace_active); + +static inline void check_stack(void) +{ + unsigned long this_size; + unsigned long flags; + + this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1); + this_size = THREAD_SIZE - this_size; + + if (this_size <= max_stack_size) + return; + + raw_local_irq_save(flags); + __raw_spin_lock(&max_stack_lock); + + /* a race could have already updated it */ + if (this_size <= max_stack_size) + goto out; + + max_stack_size = this_size; + + max_stack_trace.nr_entries = 0; + max_stack_trace.skip = 1; + + save_stack_trace(&max_stack_trace); + + out: + __raw_spin_unlock(&max_stack_lock); + raw_local_irq_restore(flags); +} + +static void +stack_trace_call(unsigned long ip, unsigned long parent_ip) +{ + int cpu, resched; + + if (unlikely(!ftrace_enabled || stack_trace_disabled)) + return; + + resched = need_resched(); + preempt_disable_notrace(); + + cpu = raw_smp_processor_id(); + /* no atomic needed, we only modify this variable by this cpu */ + if (per_cpu(trace_active, cpu)++ != 0) + goto out; + + check_stack(); + + out: + per_cpu(trace_active, cpu)--; + /* prevent recursion in schedule */ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = stack_trace_call, +}; + +static ssize_t +stack_max_size_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + unsigned long *ptr = filp->private_data; + char buf[64]; + int r; + + r = snprintf(buf, sizeof(buf), "%ld\n", *ptr); + if (r > sizeof(buf)) + r = sizeof(buf); + return simple_read_from_buffer(ubuf, count, ppos, buf, r); +} + +static ssize_t +stack_max_size_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + long *ptr = filp->private_data; + unsigned long val, flags; + char buf[64]; + int ret; + + if (count >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, count)) + return -EFAULT; + + buf[count] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + raw_local_irq_save(flags); + __raw_spin_lock(&max_stack_lock); + *ptr = val; + __raw_spin_unlock(&max_stack_lock); + raw_local_irq_restore(flags); + + return count; +} + +static struct file_operations stack_max_size_fops = { + .open = tracing_open_generic, + .read = stack_max_size_read, + .write = stack_max_size_write, +}; + +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + unsigned long *t = m->private; + + (*pos)++; + + if (!t || *t == ULONG_MAX) + return NULL; + + t++; + m->private = t; + + return t; +} + +static void *t_start(struct seq_file *m, loff_t *pos) +{ + unsigned long *t = m->private; + loff_t l = 0; + + local_irq_disable(); + __raw_spin_lock(&max_stack_lock); + + for (; t && l < *pos; t = t_next(m, t, &l)) + ; + + return t; +} + +static void t_stop(struct seq_file *m, void *p) +{ + __raw_spin_unlock(&max_stack_lock); + local_irq_enable(); +} + +static int trace_lookup_stack(struct seq_file *m, unsigned long addr) +{ +#ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; + + sprint_symbol(str, addr); + + return seq_printf(m, "[<%p>] %s\n", (void*)addr, str); +#else + return seq_printf(m, "%p\n", (void*)addr); +#endif +} + +static int t_show(struct seq_file *m, void *v) +{ + unsigned long *t = v; + + if (!t || *t == ULONG_MAX) + return 0; + + trace_lookup_stack(m, *t); + + return 0; +} + +static struct seq_operations stack_trace_seq_ops = { + .start = t_start, + .next = t_next, + .stop = t_stop, + .show = t_show, +}; + +static int stack_trace_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = seq_open(file, &stack_trace_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = stack_dump_trace; + } + + return ret; +} + +static struct file_operations stack_trace_fops = { + .open = stack_trace_open, + .read = seq_read, + .llseek = seq_lseek, +}; + +static __init int stack_trace_init(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + + d_tracer = tracing_init_dentry(); + + entry = debugfs_create_file("stack_max_size", 0644, d_tracer, + &max_stack_size, &stack_max_size_fops); + if (!entry) + pr_warning("Could not create debugfs 'stack_max_size' entry\n"); + + entry = debugfs_create_file("stack_trace", 0444, d_tracer, + NULL, &stack_trace_fops); + if (!entry) + pr_warning("Could not create debugfs 'stack_trace' entry\n"); + + register_ftrace_function(&trace_ops); + + return 0; +} + +device_initcall(stack_trace_init); -- cgit v1.1 From 3b47bfc1fca01cccad9cce2d18b79b18ef2e4131 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 27 Aug 2008 23:24:15 -0400 Subject: ftrace: remove direct reference to mcount in trace code The mcount record method of ftrace scans objdump for references to mcount. Using mcount as the reference to test if the calls to mcount being replaced are indeed calls to mcount, this use of mcount was also caught as a location to change. Using a variable that points to the mcount address moves this reference into the data section that is not scanned, and we do not use a false location to try and modify. The warn on code was what was used to detect this bug. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 969a83f..b69966f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -37,6 +37,14 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* + * Since MCOUNT_ADDR may point to mcount itself, we do not want + * to get it confused by reading a reference in the code as we + * are parsing on objcopy output of text. Use a variable for + * it instead. + */ +static unsigned long mcount_addr = MCOUNT_ADDR; + +/* * ftrace_disabled is set when an anomaly is discovered. * ftrace_disabled is much stronger than ftrace_enabled. */ @@ -577,7 +585,7 @@ ftrace_code_disable(struct dyn_ftrace *rec) ip = rec->ip; nop = ftrace_nop_replace(); - call = ftrace_call_replace(ip, MCOUNT_ADDR); + call = ftrace_call_replace(ip, mcount_addr); failed = ftrace_modify_code(ip, call, nop); if (failed) { -- cgit v1.1 From 1b6cced6ec9677fa65471e890dfdcb4bf5387643 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 29 Aug 2008 16:51:43 -0400 Subject: ftrace: stack trace add indexes This patch adds indexes into the stack that the functions in the stack dump were found at. As an added bonus, I also added a diff to show which function is the most notorious consumer of the stack. The output now looks like this: # cat /debug/tracing/stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 2476 212 blk_recount_segments+0x39/0x59 1) 2264 12 bio_phys_segments+0x16/0x1d 2) 2252 20 blk_rq_bio_prep+0x23/0xaf 3) 2232 12 init_request_from_bio+0x74/0x77 4) 2220 56 __make_request+0x294/0x331 5) 2164 136 generic_make_request+0x34f/0x37d 6) 2028 56 submit_bio+0xe7/0xef 7) 1972 28 submit_bh+0xd1/0xf0 8) 1944 112 block_read_full_page+0x299/0x2a9 9) 1832 8 blkdev_readpage+0x14/0x16 10) 1824 28 read_cache_page_async+0x7e/0x109 11) 1796 16 read_cache_page+0x11/0x49 12) 1780 32 read_dev_sector+0x3c/0x72 13) 1748 48 read_lba+0x4d/0xaa 14) 1700 168 efi_partition+0x85/0x61b 15) 1532 72 rescan_partitions+0x10e/0x266 16) 1460 40 do_open+0x1c7/0x24e 17) 1420 292 __blkdev_get+0x79/0x84 18) 1128 12 blkdev_get+0x12/0x14 19) 1116 20 register_disk+0xd1/0x11e 20) 1096 28 add_disk+0x34/0x90 21) 1068 52 sd_probe+0x2b1/0x366 22) 1016 20 driver_probe_device+0xa5/0x120 23) 996 8 __device_attach+0xd/0xf 24) 988 32 bus_for_each_drv+0x3e/0x68 25) 956 24 device_attach+0x56/0x6c 26) 932 16 bus_attach_device+0x26/0x4d 27) 916 64 device_add+0x380/0x4b4 28) 852 28 scsi_sysfs_add_sdev+0xa1/0x1c9 29) 824 160 scsi_probe_and_add_lun+0x919/0xa2a 30) 664 36 __scsi_add_device+0x88/0xae 31) 628 44 ata_scsi_scan_host+0x9e/0x21c 32) 584 28 ata_host_register+0x1cb/0x1db 33) 556 24 ata_host_activate+0x98/0xb5 34) 532 192 ahci_init_one+0x9bd/0x9e9 35) 340 20 pci_device_probe+0x3e/0x5e 36) 320 20 driver_probe_device+0xa5/0x120 37) 300 20 __driver_attach+0x3f/0x5e 38) 280 36 bus_for_each_dev+0x40/0x62 39) 244 12 driver_attach+0x19/0x1b 40) 232 28 bus_add_driver+0x9c/0x1af 41) 204 28 driver_register+0x76/0xd2 42) 176 20 __pci_register_driver+0x44/0x71 43) 156 8 ahci_init+0x14/0x16 44) 148 100 _stext+0x42/0x122 45) 48 20 kernel_init+0x175/0x1dc 46) 28 28 kernel_thread_helper+0x7/0x10 The first column is simply an index starting from the inner most function and counting down to the outer most. The next column is the location that the function was found on the stack. The next column is the size of the stack for that function. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 90 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 73 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4d1e522..74c5d9a 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -16,8 +16,10 @@ #define STACK_TRACE_ENTRIES 500 -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES] = - { [0 ... (STACK_TRACE_ENTRIES-1)] = ULONG_MAX }; +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = + { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; +static unsigned stack_dump_index[STACK_TRACE_ENTRIES]; + static struct stack_trace max_stack_trace = { .max_entries = STACK_TRACE_ENTRIES, .entries = stack_dump_trace, @@ -32,8 +34,9 @@ static DEFINE_PER_CPU(int, trace_active); static inline void check_stack(void) { - unsigned long this_size; - unsigned long flags; + unsigned long this_size, flags; + unsigned long *p, *top, *start; + int i; this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1); this_size = THREAD_SIZE - this_size; @@ -51,10 +54,42 @@ static inline void check_stack(void) max_stack_size = this_size; max_stack_trace.nr_entries = 0; - max_stack_trace.skip = 1; + max_stack_trace.skip = 3; save_stack_trace(&max_stack_trace); + /* + * Now find where in the stack these are. + */ + i = 0; + start = &this_size; + top = (unsigned long *) + (((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE); + + /* + * Loop through all the entries. One of the entries may + * for some reason be missed on the stack, so we may + * have to account for them. If they are all there, this + * loop will only happen once. This code only takes place + * on a new max, so it is far from a fast path. + */ + while (i < max_stack_trace.nr_entries) { + + stack_dump_index[i] = this_size; + p = start; + + for (; p < top && i < max_stack_trace.nr_entries; p++) { + if (*p == stack_dump_trace[i]) { + this_size = stack_dump_index[i++] = + (top - p) * sizeof(unsigned long); + /* Start the search from here */ + start = p + 1; + } + } + + i++; + } + out: __raw_spin_unlock(&max_stack_lock); raw_local_irq_restore(flags); @@ -145,22 +180,24 @@ static struct file_operations stack_max_size_fops = { static void * t_next(struct seq_file *m, void *v, loff_t *pos) { - unsigned long *t = m->private; + long i = (long)m->private; (*pos)++; - if (!t || *t == ULONG_MAX) + i++; + + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) return NULL; - t++; - m->private = t; + m->private = (void *)i; - return t; + return &m->private; } static void *t_start(struct seq_file *m, loff_t *pos) { - unsigned long *t = m->private; + void *t = &m->private; loff_t l = 0; local_irq_disable(); @@ -178,14 +215,15 @@ static void t_stop(struct seq_file *m, void *p) local_irq_enable(); } -static int trace_lookup_stack(struct seq_file *m, unsigned long addr) +static int trace_lookup_stack(struct seq_file *m, long i) { + unsigned long addr = stack_dump_trace[i]; #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; sprint_symbol(str, addr); - return seq_printf(m, "[<%p>] %s\n", (void*)addr, str); + return seq_printf(m, "%s\n", str); #else return seq_printf(m, "%p\n", (void*)addr); #endif @@ -193,12 +231,30 @@ static int trace_lookup_stack(struct seq_file *m, unsigned long addr) static int t_show(struct seq_file *m, void *v) { - unsigned long *t = v; + long i = *(long *)v; + int size; + + if (i < 0) { + seq_printf(m, " Depth Size Location" + " (%d entries)\n" + " ----- ---- --------\n", + max_stack_trace.nr_entries); + return 0; + } - if (!t || *t == ULONG_MAX) + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) return 0; - trace_lookup_stack(m, *t); + if (i+1 == max_stack_trace.nr_entries || + stack_dump_trace[i+1] == ULONG_MAX) + size = stack_dump_index[i]; + else + size = stack_dump_index[i] - stack_dump_index[i+1]; + + seq_printf(m, "%3ld) %8d %5d ", i, stack_dump_index[i], size); + + trace_lookup_stack(m, i); return 0; } @@ -217,7 +273,7 @@ static int stack_trace_open(struct inode *inode, struct file *file) ret = seq_open(file, &stack_trace_seq_ops); if (!ret) { struct seq_file *m = file->private_data; - m->private = stack_dump_trace; + m->private = (void *)-1; } return ret; -- cgit v1.1 From 2ff01c6a17391225a18256d510b6e5b4aba40aa1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 4 Sep 2008 15:04:37 +0200 Subject: stack tracer: depends on DEBUG_KERNEL Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 2a22e46..5a9cffb 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -109,6 +109,7 @@ config CONTEXT_SWITCH_TRACER config STACK_TRACER bool "Trace max stack" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select FTRACE select STACKTRACE help -- cgit v1.1 From a6168353d1c0b24b7512e14d1c3e47ed69881a23 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 20 Aug 2008 16:36:11 -0700 Subject: ftrace: make output nicely spaced for up to 999 cpus Currently some of the ftrace output goes skewiff if you have more than 9 cpus, and some if you have more than 99. Twiddle with the headers and format strings to make up to 999 cpus display without causing spacing problems. Signed-off-by: Michael Ellerman Acked-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 896e59f..1801900 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1409,21 +1409,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) static void print_lat_help_header(struct seq_file *m) { - seq_puts(m, "# _------=> CPU# \n"); - seq_puts(m, "# / _-----=> irqs-off \n"); - seq_puts(m, "# | / _----=> need-resched \n"); - seq_puts(m, "# || / _---=> hardirq/softirq \n"); - seq_puts(m, "# ||| / _--=> preempt-depth \n"); - seq_puts(m, "# |||| / \n"); - seq_puts(m, "# ||||| delay \n"); - seq_puts(m, "# cmd pid ||||| time | caller \n"); - seq_puts(m, "# \\ / ||||| \\ | / \n"); + seq_puts(m, "# _------=> CPU# \n"); + seq_puts(m, "# / _-----=> irqs-off \n"); + seq_puts(m, "# | / _----=> need-resched \n"); + seq_puts(m, "# || / _---=> hardirq/softirq \n"); + seq_puts(m, "# ||| / _--=> preempt-depth \n"); + seq_puts(m, "# |||| / \n"); + seq_puts(m, "# ||||| delay \n"); + seq_puts(m, "# cmd pid ||||| time | caller \n"); + seq_puts(m, "# \\ / ||||| \\ | / \n"); } static void print_func_help_header(struct seq_file *m) { - seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); - seq_puts(m, "# | | | | |\n"); + seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | | |\n"); } @@ -1508,7 +1508,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) comm = trace_find_cmdline(field->pid); trace_seq_printf(s, "%8.8s-%-5d ", comm, field->pid); - trace_seq_printf(s, "%d", cpu); + trace_seq_printf(s, "%3d", cpu); trace_seq_printf(s, "%c%c", (field->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', ((field->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); @@ -1598,7 +1598,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) if (verbose) { comm = trace_find_cmdline(field->pid); - trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" + trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]" " %ld.%03ldms (+%ld.%03ldms): ", comm, field->pid, cpu, field->flags, @@ -1694,7 +1694,7 @@ static int print_trace_fmt(struct trace_iterator *iter) ret = trace_seq_printf(s, "%16s-%-5d ", comm, field->pid); if (!ret) return 0; - ret = trace_seq_printf(s, "[%02d] ", iter->cpu); + ret = trace_seq_printf(s, "[%03d] ", iter->cpu); if (!ret) return 0; ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); -- cgit v1.1 From 652567aa2000f1d4a1fd434382a30d8dd4a7c980 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 3 Sep 2008 17:42:50 -0400 Subject: ftrace: binary and not logical for continue test Peter Zijlstra provided me with a nice brown paper bag while letting me know that I was doing a logical AND and not a binary one, making a condition true more often than it should be. Luckily, a false true is handled by the calling function and no harm is done. But this needs to be fixed regardless. Signed-off-by: Steven Rostedt Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1801900..9639e45 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1655,7 +1655,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) case TRACE_PRINT: seq_print_ip_sym(s, field->print.ip, sym_flags); trace_seq_printf(s, ": %s", field->print.buf); - if (field->flags && TRACE_FLAG_CONT) + if (field->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; default: @@ -1768,7 +1768,7 @@ static int print_trace_fmt(struct trace_iterator *iter) case TRACE_PRINT: seq_print_ip_sym(s, field->print.ip, sym_flags); trace_seq_printf(s, ": %s", field->print.buf); - if (field->flags && TRACE_FLAG_CONT) + if (field->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; } @@ -1833,7 +1833,7 @@ static int print_raw_fmt(struct trace_iterator *iter) case TRACE_PRINT: trace_seq_printf(s, "# %lx %s", field->print.ip, field->print.buf); - if (field->flags && TRACE_FLAG_CONT) + if (field->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; } -- cgit v1.1 From 5a90f577e5369a84b720ead42e621fcb1b8a8b21 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 3 Sep 2008 17:42:51 -0400 Subject: ftrace: print continue index fix An item in the trace buffer that is bigger than one entry may be split up using the TRACE_CONT entry. This makes it a virtual single entry. The current code increments the iterator index even while traversing TRACE_CONT entries, making it look like the iterator is further than it actually is. This patch adds code to not increment the iterator index while skipping over TRACE_CONT entries. Signed-off-by: Steven Rostedt Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9639e45..d24101c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1117,9 +1117,8 @@ trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, } /* Increment the index counter of an iterator by one */ -static void trace_iterator_increment(struct trace_iterator *iter, int cpu) +static void __trace_iterator_increment(struct trace_iterator *iter, int cpu) { - iter->idx++; iter->next_idx[cpu]++; iter->next_page_idx[cpu]++; @@ -1132,6 +1131,12 @@ static void trace_iterator_increment(struct trace_iterator *iter, int cpu) } } +static void trace_iterator_increment(struct trace_iterator *iter, int cpu) +{ + iter->idx++; + __trace_iterator_increment(iter, cpu); +} + static struct trace_entry * trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data, struct trace_iterator *iter, int cpu) @@ -1153,7 +1158,7 @@ trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data, /* find a real entry */ do { - trace_iterator_increment(iter, cpu); + __trace_iterator_increment(iter, cpu); ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); } while (ent && ent->type != TRACE_CONT); @@ -1187,7 +1192,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, int inc) ent = trace_entry_next(tr, data, iter, cpu); else { while (ent && ent->type == TRACE_CONT) { - trace_iterator_increment(iter, cpu); + __trace_iterator_increment(iter, cpu); ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); } @@ -1566,7 +1571,7 @@ trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) do { trace_seq_printf(s, "%s", ent->cont.buf); - trace_iterator_increment(iter, iter->cpu); + __trace_iterator_increment(iter, iter->cpu); ent = trace_entry_idx(tr, data, iter, iter->cpu); } while (ent && ent->type == TRACE_CONT); } -- cgit v1.1 From f09ce573f57ddc35c67b39e51f34545877b30031 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 4 Sep 2008 10:24:14 +0200 Subject: ftrace: make ftrace_printk usable with the other tracers Currently ftrace_printk only works with the ftrace tracer, switch it to an iter_ctrl setting so we can make us of them with other tracers too. [rostedt@redhat.com: tweak to the disable condition] Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 8 +++++--- kernel/trace/trace.h | 1 + 2 files changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d24101c..8a00d6c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -235,6 +235,7 @@ static const char *trace_options[] = { "block", "stacktrace", "sched-tree", + "ftrace_printk", NULL }; @@ -3091,9 +3092,10 @@ static __init void tracer_init_debugfs(void) int __ftrace_printk(unsigned long ip, const char *fmt, ...) { - struct trace_array *tr = &global_trace; static DEFINE_SPINLOCK(trace_buf_lock); static char trace_buf[TRACE_BUF_SIZE]; + + struct trace_array *tr = &global_trace; struct trace_array_cpu *data; struct trace_entry *entry; unsigned long flags; @@ -3101,7 +3103,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) va_list ap; int cpu, len = 0, write, written = 0; - if (likely(!ftrace_function_enabled)) + if (!(trace_flags & TRACE_ITER_PRINTK) || !tr->ctrl || tracing_disabled) return 0; local_irq_save(flags); @@ -3109,7 +3111,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); - if (unlikely(disabled != 1 || !ftrace_function_enabled)) + if (unlikely(disabled != 1)) goto out; spin_lock(&trace_buf_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 50b6d7a..5f54c87 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -356,6 +356,7 @@ enum trace_iterator_flags { TRACE_ITER_BLOCK = 0x80, TRACE_ITER_STACKTRACE = 0x100, TRACE_ITER_SCHED_TREE = 0x200, + TRACE_ITER_PRINTK = 0x400, }; #endif /* _LINUX_KERNEL_TRACE_H */ -- cgit v1.1 From 80b5e940050c273ba277acbf3a9fbc1d4441e681 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 4 Sep 2008 10:24:16 +0200 Subject: ftrace: sched_switch: show the wakee's cpu While profiling the smp behaviour of the scheduler it was needed to know to which cpu a task got woken. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 12 +++++++++--- kernel/trace/trace.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8a00d6c..7e6cb4f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -977,6 +977,7 @@ tracing_sched_switch_trace(struct trace_array *tr, entry->field.ctx.next_pid = next->pid; entry->field.ctx.next_prio = next->prio; entry->field.ctx.next_state = next->state; + entry->field.ctx.next_cpu = task_cpu(next); __trace_stack(tr, data, flags, 5); __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -1003,6 +1004,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry->field.ctx.next_pid = wakee->pid; entry->field.ctx.next_prio = wakee->prio; entry->field.ctx.next_state = wakee->state; + entry->field.ctx.next_cpu = task_cpu(wakee); __trace_stack(tr, data, flags, 6); __raw_spin_unlock(&data->lock); raw_local_irq_restore(irq_flags); @@ -1636,10 +1638,11 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) __ffs(field->ctx.prev_state) + 1 : 0; S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X'; comm = trace_find_cmdline(field->ctx.next_pid); - trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n", + trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n", field->ctx.prev_pid, field->ctx.prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", + field->ctx.next_cpu, field->ctx.next_pid, field->ctx.next_prio, T, comm); @@ -1736,11 +1739,12 @@ static int print_trace_fmt(struct trace_iterator *iter) state_to_char[field->ctx.prev_state] : 'X'; T = field->ctx.next_state < sizeof(state_to_char) ? state_to_char[field->ctx.next_state] : 'X'; - ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n", + ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n", field->ctx.prev_pid, field->ctx.prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", + field->ctx.next_cpu, field->ctx.next_pid, field->ctx.next_prio, T); @@ -1817,10 +1821,11 @@ static int print_raw_fmt(struct trace_iterator *iter) state_to_char[field->ctx.next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; - ret = trace_seq_printf(s, "%d %d %c %d %d %c\n", + ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n", field->ctx.prev_pid, field->ctx.prev_prio, S, + field->ctx.next_cpu, field->ctx.next_pid, field->ctx.next_prio, T); @@ -1893,6 +1898,7 @@ static int print_hex_fmt(struct trace_iterator *iter) SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_pid); SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_prio); SEQ_PUT_HEX_FIELD_RET(s, S); + SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_cpu); SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_pid); SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_prio); SEQ_PUT_HEX_FIELD_RET(s, T); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5f54c87..77c265f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -41,6 +41,7 @@ struct ctx_switch_entry { unsigned int next_pid; unsigned char next_prio; unsigned char next_state; + unsigned int next_cpu; }; /* -- cgit v1.1 From d3ee6d992821f471193a7ee7a00af9ebb4bf5d01 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 4 Sep 2008 14:04:51 +0200 Subject: ftrace: make it depend on DEBUG_KERNEL make most of the tracers depend on DEBUG_KERNEL - that's their intended purpose. (most distributions have DEBUG_KERNEL enabled anyway so this is not a practical limitation - but it simplifies the tracing menu in the normal case) Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5a9cffb..16e5bb5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -22,6 +22,7 @@ config TRACING config FTRACE bool "Kernel Function Tracer" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select FRAME_POINTER select TRACING select CONTEXT_SWITCH_TRACER @@ -40,6 +41,7 @@ config IRQSOFF_TRACER depends on TRACE_IRQFLAGS_SUPPORT depends on GENERIC_TIME depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACE_IRQFLAGS select TRACING select TRACER_MAX_TRACE @@ -63,6 +65,7 @@ config PREEMPT_TRACER depends on GENERIC_TIME depends on PREEMPT depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select TRACER_MAX_TRACE help @@ -90,6 +93,7 @@ config SYSPROF_TRACER config SCHED_TRACER bool "Scheduling Latency Tracer" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select CONTEXT_SWITCH_TRACER select TRACER_MAX_TRACE @@ -100,6 +104,7 @@ config SCHED_TRACER config CONTEXT_SWITCH_TRACER bool "Trace process context switches" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select MARKERS help @@ -120,6 +125,7 @@ config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FTRACE depends on HAVE_DYNAMIC_FTRACE + depends on DEBUG_KERNEL default y help This option will modify all the calls to ftrace dynamically @@ -146,6 +152,7 @@ config FTRACE_SELFTEST config FTRACE_STARTUP_TEST bool "Perform a startup test on ftrace" depends on TRACING + depends on DEBUG_KERNEL select FTRACE_SELFTEST help This option performs a series of startup tests on ftrace. On bootup -- cgit v1.1 From 644f991d4b920ab1f5043509651479420b293490 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 6 Sep 2008 01:06:04 -0400 Subject: ftrace: fix unlocking of hash This must be brown paper bag week for Steven Rostedt! While working on ftrace for PPC, I discovered that the hash locking done when CONFIG_FTRACE_MCOUNT_RECORD is not set, is totally incorrect. With a cut and paste error, I had the hash lock macro to lock for both hash_lock _and_ hash_unlock! This bug did not affect x86 since this bug was introduced when CONFIG_FTRACE_MCOUNT_RECORD was added to x86. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b69966f..c9e09d8 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -170,7 +170,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) */ static DEFINE_SPINLOCK(ftrace_hash_lock); #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) -#define ftrace_hash_unlock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) +#define ftrace_hash_unlock(flags) \ + spin_unlock_irqrestore(&ftrace_hash_lock, flags) #else /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) -- cgit v1.1 From 45dcd8b8a8ca855591e3ac882d3a7fc255d09d43 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 21:56:41 +0300 Subject: ftrace: move mmiotrace functions out of trace.c Moves the mmiotrace specific functions from trace.c to trace_mmiotrace.c. Functions trace_wake_up(), tracing_get_trace_entry(), and tracing_generic_entry_update() are therefore made available outside trace.c. Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 46 ++---------------------------------------- kernel/trace/trace.h | 15 ++++++-------- kernel/trace/trace_mmiotrace.c | 42 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+), 53 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7e6cb4f..d372bc5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -785,7 +785,7 @@ trace_next_page(struct trace_array_cpu *data, void *addr) return page_address(page); } -static inline struct trace_entry * +struct trace_entry * tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) { unsigned long idx, idx_next; @@ -821,7 +821,7 @@ tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) return entry; } -static inline void +void tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) { struct task_struct *tsk = current; @@ -865,48 +865,6 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data, trace_function(tr, data, ip, parent_ip, flags); } -#ifdef CONFIG_MMIOTRACE -void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, - struct mmiotrace_rw *rw) -{ - struct trace_entry *entry; - unsigned long irq_flags; - - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_RW; - entry->field.mmiorw = *rw; - - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); - - trace_wake_up(); -} - -void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, - struct mmiotrace_map *map) -{ - struct trace_entry *entry; - unsigned long irq_flags; - - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_MAP; - entry->field.mmiomap = *map; - - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); - - trace_wake_up(); -} -#endif - void __trace_stack(struct trace_array *tr, struct trace_array_cpu *data, unsigned long flags, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 77c265f..9d39aa0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -213,11 +213,17 @@ struct trace_iterator { long idx; }; +void trace_wake_up(void); void tracing_reset(struct trace_array_cpu *data); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); void init_tracer_sysprof_debugfs(struct dentry *d_tracer); +struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, + struct trace_array_cpu *data); +void tracing_generic_entry_update(struct trace_entry *entry, + unsigned long flags); + void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, @@ -291,15 +297,6 @@ extern unsigned long ftrace_update_tot_cnt; extern int DYN_FTRACE_TEST_NAME(void); #endif -#ifdef CONFIG_MMIOTRACE -extern void __trace_mmiotrace_rw(struct trace_array *tr, - struct trace_array_cpu *data, - struct mmiotrace_rw *rw); -extern void __trace_mmiotrace_map(struct trace_array *tr, - struct trace_array_cpu *data, - struct mmiotrace_map *map); -#endif - #ifdef CONFIG_FTRACE_STARTUP_TEST #ifdef CONFIG_FTRACE extern int trace_selftest_startup_function(struct tracer *trace, diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 9b7a936..ef02747 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -276,6 +276,27 @@ __init static int init_mmio_trace(void) } device_initcall(init_mmio_trace); +static void __trace_mmiotrace_rw(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_rw *rw) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_RW; + entry->field.mmiorw = *rw; + + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} + void mmio_trace_rw(struct mmiotrace_rw *rw) { struct trace_array *tr = mmio_trace_array; @@ -283,6 +304,27 @@ void mmio_trace_rw(struct mmiotrace_rw *rw) __trace_mmiotrace_rw(tr, data, rw); } +static void __trace_mmiotrace_map(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_map *map) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_MAP; + entry->field.mmiomap = *map; + + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} + void mmio_trace_mapping(struct mmiotrace_map *map) { struct trace_array *tr = mmio_trace_array; -- cgit v1.1 From 801fe40001dfc263848552fb28924b766ed44ea4 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 21:58:24 +0300 Subject: ftrace: add trace_vprintk() trace_vprintk() for easier implementation of tracer specific *_printk functions. Add check check for no_tracer, and implement __ftrace_printk() as a wrapper. Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 24 ++++++++++++++++++------ kernel/trace/trace.h | 1 + 2 files changed, 19 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d372bc5..406de9c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3054,7 +3054,7 @@ static __init void tracer_init_debugfs(void) (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) #define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) -int __ftrace_printk(unsigned long ip, const char *fmt, ...) +int trace_vprintk(unsigned long ip, const char *fmt, va_list args) { static DEFINE_SPINLOCK(trace_buf_lock); static char trace_buf[TRACE_BUF_SIZE]; @@ -3064,10 +3064,9 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) struct trace_entry *entry; unsigned long flags; long disabled; - va_list ap; int cpu, len = 0, write, written = 0; - if (!(trace_flags & TRACE_ITER_PRINTK) || !tr->ctrl || tracing_disabled) + if (current_trace == &no_tracer || !tr->ctrl || tracing_disabled) return 0; local_irq_save(flags); @@ -3079,9 +3078,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) goto out; spin_lock(&trace_buf_lock); - va_start(ap, fmt); - len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, ap); - va_end(ap); + len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); len = min(len, TRACE_BUF_SIZE-1); trace_buf[len] = 0; @@ -3120,6 +3117,21 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) return len; } +EXPORT_SYMBOL_GPL(trace_vprintk); + +int __ftrace_printk(unsigned long ip, const char *fmt, ...) +{ + int ret; + va_list ap; + + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; + + va_start(ap, fmt); + ret = trace_vprintk(ip, fmt, ap); + va_end(ap); + return ret; +} EXPORT_SYMBOL_GPL(__ftrace_printk); static int trace_panic_handler(struct notifier_block *this, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9d39aa0..be3b3cf 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -333,6 +333,7 @@ extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); +extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; -- cgit v1.1 From 9e57fb35d711331a9b1410c5c56ebeb3733428a0 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 22:00:34 +0300 Subject: x86 mmiotrace: implement mmiotrace_printk() Offer mmiotrace users a function to inject markers from inside the kernel. This depends on the trace_vprintk() patch. Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_mmiotrace.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index ef02747..767d1fa 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -335,3 +335,8 @@ void mmio_trace_mapping(struct mmiotrace_map *map) __trace_mmiotrace_map(tr, data, map); preempt_enable(); } + +int mmio_trace_printk(const char *fmt, va_list args) +{ + return trace_vprintk(0, fmt, args); +} -- cgit v1.1 From fc5e27ae4b45a0619701a83f30d9b7fad7ed9400 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 22:02:27 +0300 Subject: mmiotrace: handle TRACE_PRINT entries Also make trace_seq_print_cont() non-static, and add a newline if the seq buffer can't hold all data. Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 31 +++++++++++-------------------- kernel/trace/trace.h | 19 +++++++++++++++++++ kernel/trace/trace_mmiotrace.c | 23 +++++++++++++++++++++++ 3 files changed, 53 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 406de9c..7e7154f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -200,23 +200,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs) } /* - * trace_flag_type is an enumeration that holds different - * states when a trace occurs. These are: - * IRQS_OFF - interrupts were disabled - * NEED_RESCED - reschedule is requested - * HARDIRQ - inside an interrupt handler - * SOFTIRQ - inside a softirq handler - * CONT - multiple entries hold the trace item - */ -enum trace_flag_type { - TRACE_FLAG_IRQS_OFF = 0x01, - TRACE_FLAG_NEED_RESCHED = 0x02, - TRACE_FLAG_HARDIRQ = 0x04, - TRACE_FLAG_SOFTIRQ = 0x08, - TRACE_FLAG_CONT = 0x10, -}; - -/* * TRACE_ITER_SYM_MASK masks the options in trace_flags that * control the output of kernel symbols. */ @@ -1517,12 +1500,16 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; -static void -trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) +/* + * The message is supposed to contain an ending newline. + * If the printing stops prematurely, try to add a newline of our own. + */ +void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) { struct trace_array *tr = iter->tr; struct trace_array_cpu *data = tr->data[iter->cpu]; struct trace_entry *ent; + bool ok = true; ent = trace_entry_idx(tr, data, iter, iter->cpu); if (!ent || ent->type != TRACE_CONT) { @@ -1531,10 +1518,14 @@ trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) } do { - trace_seq_printf(s, "%s", ent->cont.buf); + if (ok) + ok = (trace_seq_printf(s, "%s", ent->cont.buf) > 0); __trace_iterator_increment(iter, iter->cpu); ent = trace_entry_idx(tr, data, iter, iter->cpu); } while (ent && ent->type == TRACE_CONT); + + if (!ok) + trace_seq_putc(s, '\n'); } static int diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index be3b3cf..648433d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -72,6 +72,23 @@ struct print_entry { }; /* + * trace_flag_type is an enumeration that holds different + * states when a trace occurs. These are: + * IRQS_OFF - interrupts were disabled + * NEED_RESCED - reschedule is requested + * HARDIRQ - inside an interrupt handler + * SOFTIRQ - inside a softirq handler + * CONT - multiple entries hold the trace item + */ +enum trace_flag_type { + TRACE_FLAG_IRQS_OFF = 0x01, + TRACE_FLAG_NEED_RESCHED = 0x02, + TRACE_FLAG_HARDIRQ = 0x04, + TRACE_FLAG_SOFTIRQ = 0x08, + TRACE_FLAG_CONT = 0x10, +}; + +/* * The trace field - the most basic unit of tracing. This is what * is printed in the end as a single line in the trace output, such as: * @@ -330,6 +347,8 @@ extern int trace_selftest_startup_sysprof(struct tracer *trace, extern void *head_page(struct trace_array_cpu *data); extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); +extern void trace_seq_print_cont(struct trace_seq *s, + struct trace_iterator *iter); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 767d1fa..a108c32 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -245,6 +245,27 @@ static int mmio_print_map(struct trace_iterator *iter) return 0; } +static int mmio_print_mark(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + const char *msg = entry->field.print.buf; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(entry->field.t); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret; + + /* The trailing newline must be in the message. */ + ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg); + if (!ret) + return 0; + + if (entry->field.flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + + return 1; +} + /* return 0 to abort printing without consuming current entry in pipe mode */ static int mmio_print_line(struct trace_iterator *iter) { @@ -253,6 +274,8 @@ static int mmio_print_line(struct trace_iterator *iter) return mmio_print_rw(iter); case TRACE_MMIO_MAP: return mmio_print_map(iter); + case TRACE_PRINT: + return mmio_print_mark(iter); default: return 1; /* ignore unknown entries */ } -- cgit v1.1 From 5bf9a1ee350a10feb94107de32a203d81fbbe706 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 22:06:42 +0300 Subject: ftrace: inject markers via trace_marker file MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Allow a user to inject a marker (TRACE_PRINT entry) into the trace ring buffer. The related file operations are derived from code by Frédéric Weisbecker . Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++---- kernel/trace/trace.h | 4 +++ 2 files changed, 75 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7e7154f..eee1fd9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2879,6 +2879,66 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } +static int tracing_open_mark(struct inode *inode, struct file *filp) +{ + int ret; + + ret = tracing_open_generic(inode, filp); + if (ret) + return ret; + + if (current_trace == &no_tracer) + return -ENODEV; + + return 0; +} + +static int mark_printk(const char *fmt, ...) +{ + int ret; + va_list args; + va_start(args, fmt); + ret = trace_vprintk(0, fmt, args); + va_end(args); + return ret; +} + +static ssize_t +tracing_mark_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *fpos) +{ + char *buf; + char *end; + struct trace_array *tr = &global_trace; + + if (current_trace == &no_tracer || !tr->ctrl || tracing_disabled) + return -EINVAL; + + if (cnt > TRACE_BUF_SIZE) + cnt = TRACE_BUF_SIZE; + + buf = kmalloc(cnt + 1, GFP_KERNEL); + if (buf == NULL) + return -ENOMEM; + + if (copy_from_user(buf, ubuf, cnt)) { + kfree(buf); + return -EFAULT; + } + + /* Cut from the first nil or newline. */ + buf[cnt] = '\0'; + end = strchr(buf, '\n'); + if (end) + *end = '\0'; + + cnt = mark_printk("%s\n", buf); + kfree(buf); + *fpos += cnt; + + return cnt; +} + static struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -2910,6 +2970,11 @@ static struct file_operations tracing_entries_fops = { .write = tracing_entries_write, }; +static struct file_operations tracing_mark_fops = { + .open = tracing_open_mark, + .write = tracing_mark_write, +}; + #ifdef CONFIG_DYNAMIC_FTRACE static ssize_t @@ -3027,6 +3092,12 @@ static __init void tracer_init_debugfs(void) pr_warning("Could not create debugfs " "'trace_entries' entry\n"); + entry = debugfs_create_file("trace_marker", 0220, d_tracer, + NULL, &tracing_mark_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'trace_marker' entry\n"); + #ifdef CONFIG_DYNAMIC_FTRACE entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, &ftrace_update_tot_cnt, @@ -3040,11 +3111,6 @@ static __init void tracer_init_debugfs(void) #endif } -#define TRACE_BUF_SIZE 1024 -#define TRACE_PRINT_BUF_SIZE \ - (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) -#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) - int trace_vprintk(unsigned long ip, const char *fmt, va_list args) { static DEFINE_SPINLOCK(trace_buf_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 648433d..42f65d0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -124,6 +124,10 @@ struct trace_entry { }; #define TRACE_ENTRY_SIZE sizeof(struct trace_entry) +#define TRACE_BUF_SIZE 1024 +#define TRACE_PRINT_BUF_SIZE \ + (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) +#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) /* * The CPU trace array - it consists of thousands of trace entries -- cgit v1.1 From fb1b6d8b5154c692172a424e45fbd0573295cb93 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Fri, 19 Sep 2008 03:06:43 -0700 Subject: ftrace: add nop tracer A no-op tracer which can serve two purposes: 1. A template for development of a new tracer. 2. A convenient way to see ftrace_printk() calls without an irrelevant trace making the output messy. [ mingo@elte.hu: resolved conflicts ] Signed-off-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 10 +++++++ kernel/trace/Makefile | 1 + kernel/trace/trace.h | 4 +++ kernel/trace/trace_nop.c | 65 +++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_selftest.c | 9 ++++++ 5 files changed, 89 insertions(+) create mode 100644 kernel/trace/trace_nop.c (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 16e5bb5..d7b2de7 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -101,6 +101,16 @@ config SCHED_TRACER This tracer tracks the latency of the highest priority task to be scheduled in, starting from the point it has woken up. +config NOP_TRACER + bool "NOP Tracer" + depends on HAVE_FTRACE + depends on DEBUG_KERNEL + select TRACING + help + This tracer does nothing. The primary purpose for it is to + politely print the output of ftrace_printk() calls without + the overhead of an irrelevant trace taking place. + config CONTEXT_SWITCH_TRACER bool "Trace process context switches" depends on HAVE_FTRACE diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 58ec61c..73ba13f 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_FTRACE) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o +obj-$(CONFIG_NOP_TRACER) += trace_nop.o obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 42f65d0..447d4b9 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -339,6 +339,10 @@ extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, extern int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr); #endif +#ifdef CONFIG_NOP_TRACER +extern int trace_selftest_startup_nop(struct tracer *trace, + struct trace_array *tr); +#endif #ifdef CONFIG_CONTEXT_SWITCH_TRACER extern int trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr); diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c new file mode 100644 index 0000000..dafaefb --- /dev/null +++ b/kernel/trace/trace_nop.c @@ -0,0 +1,65 @@ +/* + * nop tracer + * + * Copyright (C) 2008 Steven Noonan + * + */ + +#include +#include +#include +#include + +#include "trace.h" + +static struct trace_array *ctx_trace; + +static void start_nop_trace(struct trace_array *tr) +{ + /* Nothing to do! */ +} + +static void stop_nop_trace(struct trace_array *tr) +{ + /* Nothing to do! */ +} + +static void nop_trace_init(struct trace_array *tr) +{ + ctx_trace = tr; + + if (tr->ctrl) + start_nop_trace(tr); +} + +static void nop_trace_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_nop_trace(tr); +} + +static void nop_trace_ctrl_update(struct trace_array *tr) +{ + /* When starting a new trace, reset the buffers */ + if (tr->ctrl) + start_nop_trace(tr); + else + stop_nop_trace(tr); +} + +static struct tracer nop_trace __read_mostly = +{ + .name = "nop", + .init = nop_trace_init, + .reset = nop_trace_reset, + .ctrl_update = nop_trace_ctrl_update, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_nop, +#endif +}; + +__init static int init_nop_trace(void) +{ + return register_tracer(&nop_trace); +} +device_initcall(init_nop_trace); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 630715b..82db910 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -418,6 +418,15 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * } #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */ +#ifdef CONFIG_NOP_TRACER +int +trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr) +{ + /* What could possibly go wrong? */ + return 0; +} +#endif + #ifdef CONFIG_SCHED_TRACER static int trace_wakeup_test_thread(void *data) { -- cgit v1.1 From 71c67d58b5660f8e42c7d4c3e77cbc03fac5ed31 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Sat, 20 Sep 2008 01:00:37 -0700 Subject: ftrace: mcount_addr defined but not used When CONFIG_DYNAMIC_FTRACE isn't used, neither is mcount_addr. This patch eliminates that warning. Signed-off-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c9e09d8..7694f3e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -37,14 +37,6 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* - * Since MCOUNT_ADDR may point to mcount itself, we do not want - * to get it confused by reading a reference in the code as we - * are parsing on objcopy output of text. Use a variable for - * it instead. - */ -static unsigned long mcount_addr = MCOUNT_ADDR; - -/* * ftrace_disabled is set when an anomaly is discovered. * ftrace_disabled is much stronger than ftrace_enabled. */ @@ -178,6 +170,14 @@ static DEFINE_SPINLOCK(ftrace_hash_lock); #define ftrace_hash_unlock(flags) do { } while(0) #endif +/* + * Since MCOUNT_ADDR may point to mcount itself, we do not want + * to get it confused by reading a reference in the code as we + * are parsing on objcopy output of text. Use a variable for + * it instead. + */ +static unsigned long mcount_addr = MCOUNT_ADDR; + static struct task_struct *ftraced_task; enum { -- cgit v1.1 From 8925b394eca0bb0a444a6487d702d0f650e94a10 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Sat, 20 Sep 2008 01:00:38 -0700 Subject: trace: remove pointless ifdefs The functions are already 'extern' anyway, so there's no problem with linkage. Removing these ifdefs also helps find any potential compiler errors. Suggested by Andrew Morton. Signed-off-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 447d4b9..c8c6870 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -319,38 +319,22 @@ extern int DYN_FTRACE_TEST_NAME(void); #endif #ifdef CONFIG_FTRACE_STARTUP_TEST -#ifdef CONFIG_FTRACE extern int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_IRQSOFF_TRACER extern int trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_PREEMPT_TRACER extern int trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr); -#endif -#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_SCHED_TRACER extern int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_NOP_TRACER extern int trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_CONTEXT_SWITCH_TRACER extern int trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_SYSPROF_TRACER extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); -#endif #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); -- cgit v1.1 From 35cb5ed01261f5669657d2f1720aca902299887d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Sun, 21 Sep 2008 20:10:14 +0200 Subject: tracing/ftrace: make nop tracer reset previous entries If nop tracer is selected, some old entries from the previous tracer could still be enqueued. Tracing have to be reset. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/trace_nop.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index dafaefb..9fb02c1 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -26,8 +26,12 @@ static void stop_nop_trace(struct trace_array *tr) static void nop_trace_init(struct trace_array *tr) { + int cpu; ctx_trace = tr; + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); + if (tr->ctrl) start_nop_trace(tr); } -- cgit v1.1 From 2a3a4f669df2164288d11406d11d5e4933bf5e53 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Sun, 21 Sep 2008 20:12:14 +0200 Subject: tracing/ftrace: tracing engine depends on Nop Tracer Now that the nop tracer is used as the default tracer by replacing the "none" tracer, tracing engine depends on it. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d7b2de7..254328d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -1,8 +1,13 @@ # # Architectures that offer an FTRACE implementation should select HAVE_FTRACE: # + +config NOP_TRACER + bool + config HAVE_FTRACE bool + select NOP_TRACER config HAVE_DYNAMIC_FTRACE bool @@ -101,16 +106,6 @@ config SCHED_TRACER This tracer tracks the latency of the highest priority task to be scheduled in, starting from the point it has woken up. -config NOP_TRACER - bool "NOP Tracer" - depends on HAVE_FTRACE - depends on DEBUG_KERNEL - select TRACING - help - This tracer does nothing. The primary purpose for it is to - politely print the output of ftrace_printk() calls without - the overhead of an irrelevant trace taking place. - config CONTEXT_SWITCH_TRACER bool "Trace process context switches" depends on HAVE_FTRACE -- cgit v1.1 From 43a15386c4faf913f7d70a47748c266d6210cd6e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Sun, 21 Sep 2008 20:16:30 +0200 Subject: tracing/ftrace: replace none tracer by nop tracer Replace "none" tracer by the recently created "nop" tracer. Both are pretty similar except that nop accepts TRACE_PRINT or TRACE_SPECIAL entries. And as a consequence, changing the size of the ring buffer now requires that tracing has already been disabled. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 49 +++++++++--------------------------------------- kernel/trace/trace.h | 2 ++ kernel/trace/trace_nop.c | 7 +------ 3 files changed, 12 insertions(+), 46 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index eee1fd9..f2ef72f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -142,24 +142,6 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); /* trace_flags holds iter_ctrl options */ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT; -static notrace void no_trace_init(struct trace_array *tr) -{ - int cpu; - - ftrace_function_enabled = 0; - if(tr->ctrl) - for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); - tracer_enabled = 0; -} - -/* dummy trace to disable tracing */ -static struct tracer no_tracer __read_mostly = { - .name = "none", - .init = no_trace_init -}; - - /** * trace_wake_up - wake up tasks waiting for trace input * @@ -962,7 +944,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) long disabled; int cpu; - if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl) + if (tracing_disabled || !tr->ctrl) return; local_irq_save(flags); @@ -2795,6 +2777,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, unsigned long val; char buf[64]; int i, ret; + struct trace_array *tr = filp->private_data; if (cnt >= sizeof(buf)) return -EINVAL; @@ -2814,9 +2797,9 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, mutex_lock(&trace_types_lock); - if (current_trace != &no_tracer) { + if (tr->ctrl) { cnt = -EBUSY; - pr_info("ftrace: set current_tracer to none" + pr_info("ftrace: please disable tracing" " before modifying buffer size\n"); goto out; } @@ -2879,20 +2862,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } -static int tracing_open_mark(struct inode *inode, struct file *filp) -{ - int ret; - - ret = tracing_open_generic(inode, filp); - if (ret) - return ret; - - if (current_trace == &no_tracer) - return -ENODEV; - - return 0; -} - static int mark_printk(const char *fmt, ...) { int ret; @@ -2911,7 +2880,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, char *end; struct trace_array *tr = &global_trace; - if (current_trace == &no_tracer || !tr->ctrl || tracing_disabled) + if (!tr->ctrl || tracing_disabled) return -EINVAL; if (cnt > TRACE_BUF_SIZE) @@ -2971,7 +2940,7 @@ static struct file_operations tracing_entries_fops = { }; static struct file_operations tracing_mark_fops = { - .open = tracing_open_mark, + .open = tracing_open_generic, .write = tracing_mark_write, }; @@ -3123,7 +3092,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) long disabled; int cpu, len = 0, write, written = 0; - if (current_trace == &no_tracer || !tr->ctrl || tracing_disabled) + if (!tr->ctrl || tracing_disabled) return 0; local_irq_save(flags); @@ -3539,8 +3508,8 @@ __init static int tracer_alloc_buffers(void) trace_init_cmdlines(); - register_tracer(&no_tracer); - current_trace = &no_tracer; + register_tracer(&nop_trace); + current_trace = &nop_trace; /* All seems OK, enable tracing */ global_trace.ctrl = tracer_enabled; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c8c6870..cb2c3fb 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -369,4 +369,6 @@ enum trace_iterator_flags { TRACE_ITER_PRINTK = 0x400, }; +extern struct tracer nop_trace; + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 9fb02c1..16c9ba0 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -51,7 +51,7 @@ static void nop_trace_ctrl_update(struct trace_array *tr) stop_nop_trace(tr); } -static struct tracer nop_trace __read_mostly = +struct tracer nop_trace __read_mostly = { .name = "nop", .init = nop_trace_init, @@ -62,8 +62,3 @@ static struct tracer nop_trace __read_mostly = #endif }; -__init static int init_nop_trace(void) -{ - return register_tracer(&nop_trace); -} -device_initcall(init_nop_trace); -- cgit v1.1 From 05736a427f7e16be948ccbf39782bd3a6ae16b14 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 22 Sep 2008 14:55:47 -0700 Subject: ftrace: warn on failure to disable mcount callers With the recent updates to ftrace, there should not be any failures when modifying the code. If there is, then we need to warn about it. This patch has a cleaned up version of the code that I used to discover that the weak symbols were causing failures. Signed-off-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7694f3e..4dda4f6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -576,6 +576,16 @@ static void ftrace_shutdown_replenish(void) ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); } +static void print_ip_ins(const char *fmt, unsigned char *p) +{ + int i; + + printk(KERN_CONT "%s", fmt); + + for (i = 0; i < MCOUNT_INSN_SIZE; i++) + printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); +} + static int ftrace_code_disable(struct dyn_ftrace *rec) { @@ -590,6 +600,23 @@ ftrace_code_disable(struct dyn_ftrace *rec) failed = ftrace_modify_code(ip, call, nop); if (failed) { + switch (failed) { + case 1: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on modifying "); + print_ip_sym(ip); + break; + case 2: + WARN_ON_ONCE(1); + pr_info("ftrace failed to modify "); + print_ip_sym(ip); + print_ip_ins(" expected: ", call); + print_ip_ins(" actual: ", (unsigned char *)ip); + print_ip_ins(" replace: ", nop); + printk(KERN_CONT "\n"); + break; + } + rec->flags |= FTRACE_FL_FAILED; return 0; } -- cgit v1.1 From d74185ed27651ad8d920b37d7851306ad01f7d6f Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Mon, 29 Sep 2008 16:00:05 +0800 Subject: markers: fix unregister bug and reenter bug unregister bug: codes using makers are typically calling marker_probe_unregister() and then destroying the data that marker_probe_func needs(or unloading this module). This is bug when the corresponding marker_probe_func is still running(on other cpus), it is using the destroying/ed data. we should call synchronize_sched() after marker_update_probes(). reenter bug: marker_probe_register(), marker_probe_unregister() and marker_probe_unregister_private_data() are not reentrant safe functions. these 3 functions release markers_mutex and then require it again and do "entry->oldptr = old; ...", but entry->oldptr maybe is using now for these 3 functions may reenter when markers_mutex is released. we use synchronize_sched() instead of call_rcu_sched() to fix this bug. actually we can do: " if (entry->rcu_pending) rcu_barrier_sched(); " after require markers_mutex again. but synchronize_sched() is better and simpler. For these 3 functions are not critical path. Signed-off-by: Lai Jiangshan Cc: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/marker.c | 52 ++++++---------------------------------------------- 1 file changed, 6 insertions(+), 46 deletions(-) (limited to 'kernel') diff --git a/kernel/marker.c b/kernel/marker.c index 7d1faec..9f76c4a 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -60,9 +60,6 @@ struct marker_entry { struct marker_probe_closure single; struct marker_probe_closure *multi; int refcount; /* Number of times armed. 0 if disarmed. */ - struct rcu_head rcu; - void *oldptr; - unsigned char rcu_pending:1; unsigned char ptype:1; char name[0]; /* Contains name'\0'format'\0' */ }; @@ -199,16 +196,6 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...) } EXPORT_SYMBOL_GPL(marker_probe_cb_noarg); -static void free_old_closure(struct rcu_head *head) -{ - struct marker_entry *entry = container_of(head, - struct marker_entry, rcu); - kfree(entry->oldptr); - /* Make sure we free the data before setting the pending flag to 0 */ - smp_wmb(); - entry->rcu_pending = 0; -} - static void debug_print_probes(struct marker_entry *entry) { int i; @@ -417,7 +404,6 @@ static struct marker_entry *add_marker(const char *name, const char *format) e->multi = NULL; e->ptype = 0; e->refcount = 0; - e->rcu_pending = 0; hlist_add_head(&e->hlist, head); return e; } @@ -447,9 +433,6 @@ static int remove_marker(const char *name) if (e->single.func != __mark_empty_function) return -EBUSY; hlist_del(&e->hlist); - /* Make sure the call_rcu has been executed */ - if (e->rcu_pending) - rcu_barrier_sched(); kfree(e); return 0; } @@ -479,12 +462,8 @@ static int marker_set_format(struct marker_entry **entry, const char *format) e->multi = (*entry)->multi; e->ptype = (*entry)->ptype; e->refcount = (*entry)->refcount; - e->rcu_pending = 0; hlist_add_before(&e->hlist, &(*entry)->hlist); hlist_del(&(*entry)->hlist); - /* Make sure the call_rcu has been executed */ - if ((*entry)->rcu_pending) - rcu_barrier_sched(); kfree(*entry); *entry = e; trace_mark(core_marker_format, "name %s format %s", @@ -658,12 +637,6 @@ int marker_probe_register(const char *name, const char *format, goto end; } } - /* - * If we detect that a call_rcu is pending for this marker, - * make sure it's executed now. - */ - if (entry->rcu_pending) - rcu_barrier_sched(); old = marker_entry_add_probe(entry, probe, probe_private); if (IS_ERR(old)) { ret = PTR_ERR(old); @@ -671,14 +644,11 @@ int marker_probe_register(const char *name, const char *format, } mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ + synchronize_sched(); + kfree(old); mutex_lock(&markers_mutex); entry = get_marker(name); WARN_ON(!entry); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); end: mutex_unlock(&markers_mutex); return ret; @@ -708,20 +678,15 @@ int marker_probe_unregister(const char *name, entry = get_marker(name); if (!entry) goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); old = marker_entry_remove_probe(entry, probe, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ + synchronize_sched(); + kfree(old); mutex_lock(&markers_mutex); entry = get_marker(name); if (!entry) goto end; - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(name); /* Ignore busy error message */ ret = 0; end: @@ -787,19 +752,14 @@ int marker_probe_unregister_private_data(marker_probe_func *probe, ret = -ENOENT; goto end; } - if (entry->rcu_pending) - rcu_barrier_sched(); old = marker_entry_remove_probe(entry, NULL, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ + synchronize_sched(); + kfree(old); mutex_lock(&markers_mutex); entry = get_marker_from_private_data(probe, probe_private); WARN_ON(!entry); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(entry->name); /* Ignore busy error message */ end: mutex_unlock(&markers_mutex); -- cgit v1.1 From ca2db6cf30d6a45798b7a760d0c4f7735b16799d Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 30 Sep 2008 01:49:39 -0400 Subject: tracepoints: use rcu sched Make tracepoints use rcu sched. (cleanup) Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index c7c62a4..db39961 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -80,10 +80,7 @@ static void tracepoint_entry_free_old(struct tracepoint_entry *entry, void *old) entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); -#ifdef CONFIG_PREEMPT_RCU - synchronize_sched(); /* Until we have the call_rcu_sched() */ -#endif - call_rcu(&entry->rcu, free_old_closure); + call_rcu_sched(&entry->rcu, free_old_closure); } static void debug_print_probes(struct tracepoint_entry *entry) @@ -245,9 +242,9 @@ static int remove_tracepoint(const char *name) if (e->refcount) return -EBUSY; hlist_del(&e->hlist); - /* Make sure the call_rcu has been executed */ + /* Make sure the call_rcu_sched has been executed */ if (e->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); kfree(e); return 0; } @@ -344,11 +341,11 @@ int tracepoint_probe_register(const char *name, void *probe) } } /* - * If we detect that a call_rcu is pending for this tracepoint, + * If we detect that a call_rcu_sched is pending for this tracepoint, * make sure it's executed now. */ if (entry->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); old = tracepoint_entry_add_probe(entry, probe); if (IS_ERR(old)) { ret = PTR_ERR(old); @@ -387,7 +384,7 @@ int tracepoint_probe_unregister(const char *name, void *probe) if (!entry) goto end; if (entry->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); old = tracepoint_entry_remove_probe(entry, probe); mutex_unlock(&tracepoints_mutex); tracepoint_update_probes(); /* may update entry */ -- cgit v1.1 From 9a1e9693f534174945154197fec4ec92f168ce21 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 30 Sep 2008 01:51:12 -0400 Subject: tracepoints: fix reentrancy The tracepoints had the same problem markers did have wrt reentrancy. Apply a similar fix using a rcu_barrier after each tracepoint mutex lock. Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index db39961..f2b7c28 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -356,6 +356,8 @@ int tracepoint_probe_register(const char *name, void *probe) mutex_lock(&tracepoints_mutex); entry = get_tracepoint(name); WARN_ON(!entry); + if (entry->rcu_pending) + rcu_barrier_sched(); tracepoint_entry_free_old(entry, old); end: mutex_unlock(&tracepoints_mutex); @@ -392,6 +394,8 @@ int tracepoint_probe_unregister(const char *name, void *probe) entry = get_tracepoint(name); if (!entry) goto end; + if (entry->rcu_pending) + rcu_barrier_sched(); tracepoint_entry_free_old(entry, old); remove_tracepoint(name); /* Ignore busy error message */ ret = 0; -- cgit v1.1 From e2d3b75dbc486253c910722486ac64087f96c59f Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Sep 2008 11:08:03 -0400 Subject: markers: fix unregister bug and reenter bug, cleanup Use the new rcu_read_lock_sched/unlock_sched() in marker code around the call site instead of preempt_disable/enable(). It helps reviewing the code more easily. Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/marker.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/marker.c b/kernel/marker.c index 9f76c4a..fe5ca72 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -100,11 +100,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...) char ptype; /* - * preempt_disable does two things : disabling preemption to make sure - * the teardown of the callbacks can be done correctly when they are in - * modules and they insure RCU read coherency. + * rcu_read_lock_sched does two things : disabling preemption to make + * sure the teardown of the callbacks can be done correctly when they + * are in modules and they insure RCU read coherency. */ - preempt_disable(); + rcu_read_lock_sched(); ptype = mdata->ptype; if (likely(!ptype)) { marker_probe_func *func; @@ -142,7 +142,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...) va_end(args); } } - preempt_enable(); + rcu_read_unlock_sched(); } EXPORT_SYMBOL_GPL(marker_probe_cb); @@ -159,7 +159,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...) va_list args; /* not initialized */ char ptype; - preempt_disable(); + rcu_read_lock_sched(); ptype = mdata->ptype; if (likely(!ptype)) { marker_probe_func *func; @@ -192,7 +192,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...) multi[i].func(multi[i].probe_private, call_private, mdata->format, &args); } - preempt_enable(); + rcu_read_unlock_sched(); } EXPORT_SYMBOL_GPL(marker_probe_cb_noarg); @@ -539,7 +539,7 @@ static int set_marker(struct marker_entry **entry, struct marker *elem, * Disable a marker and its probe callback. * Note: only waiting an RCU period after setting elem->call to the empty * function insures that the original callback is not used anymore. This insured - * by preempt_disable around the call site. + * by rcu_read_lock_sched around the call site. */ static void disable_marker(struct marker *elem) { -- cgit v1.1 From ed86a59071a4ccd0e9bcefc61e013759a21eda78 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 1 Oct 2008 12:03:25 -0400 Subject: markers: re-enable fast batch registration Lai Jiangshan discovered a reentrancy issue with markers and fixed it by adding synchronize_sched() calls at each registration/unregistraiton. It works, but it removes the ability to do batch registration/unregistration and can cause registration of ~100 markers to take about 30 seconds on a loaded machine (synchronize_sched() is much slower on such workloads). This patch implements a version of the fix which won't slow down marker batch registration/unregistration. It also go back to the original non-synchronized reg/unreg. Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/marker.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 52 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/marker.c b/kernel/marker.c index fe5ca72..05a2577 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -60,6 +60,9 @@ struct marker_entry { struct marker_probe_closure single; struct marker_probe_closure *multi; int refcount; /* Number of times armed. 0 if disarmed. */ + struct rcu_head rcu; + void *oldptr; + unsigned char rcu_pending:1; unsigned char ptype:1; char name[0]; /* Contains name'\0'format'\0' */ }; @@ -196,6 +199,16 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...) } EXPORT_SYMBOL_GPL(marker_probe_cb_noarg); +static void free_old_closure(struct rcu_head *head) +{ + struct marker_entry *entry = container_of(head, + struct marker_entry, rcu); + kfree(entry->oldptr); + /* Make sure we free the data before setting the pending flag to 0 */ + smp_wmb(); + entry->rcu_pending = 0; +} + static void debug_print_probes(struct marker_entry *entry) { int i; @@ -404,6 +417,7 @@ static struct marker_entry *add_marker(const char *name, const char *format) e->multi = NULL; e->ptype = 0; e->refcount = 0; + e->rcu_pending = 0; hlist_add_head(&e->hlist, head); return e; } @@ -433,6 +447,9 @@ static int remove_marker(const char *name) if (e->single.func != __mark_empty_function) return -EBUSY; hlist_del(&e->hlist); + /* Make sure the call_rcu has been executed */ + if (e->rcu_pending) + rcu_barrier_sched(); kfree(e); return 0; } @@ -462,8 +479,12 @@ static int marker_set_format(struct marker_entry **entry, const char *format) e->multi = (*entry)->multi; e->ptype = (*entry)->ptype; e->refcount = (*entry)->refcount; + e->rcu_pending = 0; hlist_add_before(&e->hlist, &(*entry)->hlist); hlist_del(&(*entry)->hlist); + /* Make sure the call_rcu has been executed */ + if ((*entry)->rcu_pending) + rcu_barrier_sched(); kfree(*entry); *entry = e; trace_mark(core_marker_format, "name %s format %s", @@ -637,6 +658,12 @@ int marker_probe_register(const char *name, const char *format, goto end; } } + /* + * If we detect that a call_rcu is pending for this marker, + * make sure it's executed now. + */ + if (entry->rcu_pending) + rcu_barrier_sched(); old = marker_entry_add_probe(entry, probe, probe_private); if (IS_ERR(old)) { ret = PTR_ERR(old); @@ -644,11 +671,16 @@ int marker_probe_register(const char *name, const char *format, } mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ - synchronize_sched(); - kfree(old); mutex_lock(&markers_mutex); entry = get_marker(name); WARN_ON(!entry); + if (entry->rcu_pending) + rcu_barrier_sched(); + entry->oldptr = old; + entry->rcu_pending = 1; + /* write rcu_pending before calling the RCU callback */ + smp_wmb(); + call_rcu_sched(&entry->rcu, free_old_closure); end: mutex_unlock(&markers_mutex); return ret; @@ -678,15 +710,22 @@ int marker_probe_unregister(const char *name, entry = get_marker(name); if (!entry) goto end; + if (entry->rcu_pending) + rcu_barrier_sched(); old = marker_entry_remove_probe(entry, probe, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ - synchronize_sched(); - kfree(old); mutex_lock(&markers_mutex); entry = get_marker(name); if (!entry) goto end; + if (entry->rcu_pending) + rcu_barrier_sched(); + entry->oldptr = old; + entry->rcu_pending = 1; + /* write rcu_pending before calling the RCU callback */ + smp_wmb(); + call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(name); /* Ignore busy error message */ ret = 0; end: @@ -752,14 +791,21 @@ int marker_probe_unregister_private_data(marker_probe_func *probe, ret = -ENOENT; goto end; } + if (entry->rcu_pending) + rcu_barrier_sched(); old = marker_entry_remove_probe(entry, NULL, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ - synchronize_sched(); - kfree(old); mutex_lock(&markers_mutex); entry = get_marker_from_private_data(probe, probe_private); WARN_ON(!entry); + if (entry->rcu_pending) + rcu_barrier_sched(); + entry->oldptr = old; + entry->rcu_pending = 1; + /* write rcu_pending before calling the RCU callback */ + smp_wmb(); + call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(entry->name); /* Ignore busy error message */ end: mutex_unlock(&markers_mutex); -- cgit v1.1 From 48043bcdf8f398d28e75ffed6ee85208d751f87f Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Wed, 8 Oct 2008 10:23:36 +0800 Subject: markers: fix unchecked format when the second, third... probe is registered, its format is not checked, this patch fixes it. Signed-off-by: Lai Jiangshan Acked-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/marker.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/marker.c b/kernel/marker.c index 05a2577..3b75d0e 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -653,11 +653,17 @@ int marker_probe_register(const char *name, const char *format, entry = get_marker(name); if (!entry) { entry = add_marker(name, format); - if (IS_ERR(entry)) { + if (IS_ERR(entry)) ret = PTR_ERR(entry); - goto end; - } + } else if (format) { + if (!entry->format) + ret = marker_set_format(&entry, format); + else if (strcmp(entry->format, format)) + ret = -EPERM; } + if (ret) + goto end; + /* * If we detect that a call_rcu is pending for this marker, * make sure it's executed now. -- cgit v1.1 From 1b7ae37c030a9fbbb5ebbf5d7bbfd7208cf805b7 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 10 Oct 2008 14:43:57 +0800 Subject: markers: bit-field is not thread-safe nor smp-safe bit-field is not thread-safe nor smp-safe. struct marker_entry.rcu_pending is not protected by any lock in rcu-callback free_old_closure(). so we must turn it into a safe type. detail: I suppose rcu_pending and ptype are store in struct marker_entry.tmp1 free_old_closure() side: change ptype side: | load struct marker_entry.tmp1 --------------------------------|-------------------------------- | change ptype bit in tmp1 load struct marker_entry.tmp1 | change rcu_pending bit in tmp1 | store tmp1 | --------------------------------|-------------------------------- | store tmp1 now this result equals that free_old_closure() do not change rcu_pending bit, bug! This bug will cause redundant rcu_barrier_sched() called. not too harmful. ----- corresponding: free_old_closure() side: change ptype side: load struct marker_entry.tmp1 | --------------------------------|-------------------------------- | load struct marker_entry.tmp1 change rcu_pending bit in tmp1 | | change ptype bit in tmp1 | store tmp1 --------------------------------|-------------------------------- store tmp1 | now this result equals that change ptype side do not change ptype bit, bug! this bug cause marker_probe_cb() access to invalid memory. oops! see also: http://en.wikipedia.org/wiki/Bit_field Signed-off-by: Lai Jiangshan Acked-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- kernel/marker.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/marker.c b/kernel/marker.c index 3b75d0e..e9c6b2b 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -62,7 +62,7 @@ struct marker_entry { int refcount; /* Number of times armed. 0 if disarmed. */ struct rcu_head rcu; void *oldptr; - unsigned char rcu_pending:1; + int rcu_pending; unsigned char ptype:1; char name[0]; /* Contains name'\0'format'\0' */ }; -- cgit v1.1 From d13744cd6e3fef373a3fe656ac349b4e7c49ff79 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Tue, 23 Sep 2008 11:32:08 +0100 Subject: tracing/ftrace: add the boot tracer Add the boot/initcall tracer. It's primary purpose is to be able to trace the initcalls. It is intended to be used with scripts/bootgraph.pl after some small improvements. Note that it is not active after its init. To avoid tracing (and so crashing) before the whole tracing engine init, you have to explicitly call start_boot_trace() after do_pre_smp_initcalls() to enable it. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 4 ++ kernel/trace/trace_boot.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 105 insertions(+) create mode 100644 kernel/trace/trace_boot.c (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cb2c3fb..b28bf88 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -6,6 +6,7 @@ #include #include #include +#include enum trace_type { __TRACE_FIRST_TYPE = 0, @@ -19,6 +20,7 @@ enum trace_type { TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, + TRACE_BOOT, __TRACE_LAST_TYPE }; @@ -30,6 +32,7 @@ struct ftrace_entry { unsigned long ip; unsigned long parent_ip; }; +extern struct tracer boot_tracer; /* * Context switch trace entry - which task (and prio) we switched from/to: @@ -108,6 +111,7 @@ struct trace_field { struct print_entry print; struct mmiotrace_rw mmiorw; struct mmiotrace_map mmiomap; + struct boot_trace initcall; }; }; diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c new file mode 100644 index 0000000..c65ef8f --- /dev/null +++ b/kernel/trace/trace_boot.c @@ -0,0 +1,101 @@ +/* + * ring buffer based initcalls tracer + * + * Copyright (C) 2008 Frederic Weisbecker + * + */ + +#include +#include +#include + +#include "trace.h" + +static struct trace_array *boot_trace; +static int trace_boot_enabled; + + +/* Should be started after do_pre_smp_initcalls() in init/main.c */ +void start_boot_trace(void) +{ + trace_boot_enabled = 1; +} + +void stop_boot_trace(struct trace_array *tr) +{ + trace_boot_enabled = 0; +} + +static void boot_trace_init(struct trace_array *tr) +{ + int cpu; + boot_trace = tr; + + trace_boot_enabled = 0; + + for_each_cpu_mask(cpu, cpu_possible_map) + tracing_reset(tr->data[cpu]); +} + +static void boot_trace_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_boot_trace(); + else + stop_boot_trace(tr); +} + +static int initcall_print_line(struct trace_iterator *iter) +{ + int ret = 1; + struct trace_entry *entry = iter->ent; + struct boot_trace *it = &entry->field.initcall; + struct trace_seq *s = &iter->seq; + + if (iter->ent->type == TRACE_BOOT) + ret = trace_seq_printf(s, "%pF called from %i " + "returned %d after %lld msecs\n", + it->func, it->caller, it->result, + it->duration); + if (ret) + return 1; + return 0; +} + +struct tracer boot_tracer __read_mostly = +{ + .name = "initcall", + .init = boot_trace_init, + .reset = stop_boot_trace, + .ctrl_update = boot_trace_ctrl_update, + .print_line = initcall_print_line, +}; + + +void trace_boot(struct boot_trace *it) +{ + struct trace_entry *entry; + struct trace_array_cpu *data; + unsigned long irq_flags; + struct trace_array *tr = boot_trace; + + if (!trace_boot_enabled) + return; + + preempt_disable(); + data = tr->data[smp_processor_id()]; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_BOOT; + entry->field.initcall = *it; + + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + trace_wake_up(); + + preempt_enable(); +} -- cgit v1.1 From b5ad384e79add1d87fff54070000dadcf218ffab Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Tue, 23 Sep 2008 11:34:32 +0100 Subject: tracing/ftrace: make tracing suitable to run the boot tracer The tracing engine have now to be init in early_initcall to set the boot tracer. Only the debugfs settings will be initialized at fs_initcall time. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f2ef72f..6ada059 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2990,7 +2990,7 @@ struct dentry *tracing_init_dentry(void) #include "trace_selftest.c" #endif -static __init void tracer_init_debugfs(void) +static __init int tracer_init_debugfs(void) { struct dentry *d_tracer; struct dentry *entry; @@ -3078,6 +3078,7 @@ static __init void tracer_init_debugfs(void) #ifdef CONFIG_SYSPROF_TRACER init_tracer_sysprof_debugfs(d_tracer); #endif + return 0; } int trace_vprintk(unsigned long ip, const char *fmt, va_list args) @@ -3504,17 +3505,20 @@ __init static int tracer_alloc_buffers(void) pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE); pr_info(" actual entries %ld\n", global_trace.entries); - tracer_init_debugfs(); - trace_init_cmdlines(); register_tracer(&nop_trace); +#ifdef CONFIG_BOOT_TRACER + register_tracer(&boot_tracer); + current_trace = &boot_tracer; + current_trace->init(&global_trace); +#else current_trace = &nop_trace; +#endif /* All seems OK, enable tracing */ global_trace.ctrl = tracer_enabled; tracing_disabled = 0; - atomic_notifier_chain_register(&panic_notifier_list, &trace_panic_notifier); @@ -3548,4 +3552,5 @@ __init static int tracer_alloc_buffers(void) } return ret; } -fs_initcall(tracer_alloc_buffers); +early_initcall(tracer_alloc_buffers); +fs_initcall(tracer_init_debugfs); -- cgit v1.1 From 1f5c2abbdeb2bb07b20c6a66bfecefe6c867b1ee Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Tue, 23 Sep 2008 11:36:20 +0100 Subject: tracing/ftrace: give an entry on the config for boot tracer Bring the entry to choose the boot tracer on the kernel config. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 12 ++++++++++++ kernel/trace/Makefile | 1 + 2 files changed, 13 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 254328d..81a17ef 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -116,6 +116,18 @@ config CONTEXT_SWITCH_TRACER This tracer gets called from the context switch and records all switching of tasks. +config BOOT_TRACER + bool "Trace boot initcalls" + depends on HAVE_FTRACE + depends on DEBUG_KERNEL + select TRACING + help + This tracer helps developers to optimize boot times: it records + the timings of the initcalls. Its aim is to be parsed by the + /scripts/bootgraph.pl tool to produce pretty graphics about + boot inefficiencies, giving a visual representation of the + delays during initcalls. + config STACK_TRACER bool "Trace max stack" depends on HAVE_FTRACE diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 73ba13f..35a07f7 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -22,5 +22,6 @@ obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o obj-$(CONFIG_NOP_TRACER) += trace_nop.o obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o +obj-$(CONFIG_BOOT_TRACER) += trace_boot.o libftrace-y := ftrace.o -- cgit v1.1 From 3ce2b9200da8b7170cc7463b7ee4212fad7b291e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Wed, 24 Sep 2008 10:36:09 +0100 Subject: ftrace/fastboot: disable tracers self-tests when boot tracer is selected The tracing engine resets the ring buffer and the tracers touch it too during self-tests. These self-tests happen during tracers registering and work against boot tracing which is logging initcalls. We have to disable tracing self-tests if the boot-tracer is selected. Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 81a17ef..4feb3c8 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -126,7 +126,9 @@ config BOOT_TRACER the timings of the initcalls. Its aim is to be parsed by the /scripts/bootgraph.pl tool to produce pretty graphics about boot inefficiencies, giving a visual representation of the - delays during initcalls. + delays during initcalls. Note that tracers self tests can't + be enabled if this tracer is selected since only one tracer + should touch the tracing buffer at a time. config STACK_TRACER bool "Trace max stack" @@ -168,8 +170,7 @@ config FTRACE_SELFTEST config FTRACE_STARTUP_TEST bool "Perform a startup test on ftrace" - depends on TRACING - depends on DEBUG_KERNEL + depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER select FTRACE_SELFTEST help This option performs a series of startup tests on ftrace. On bootup -- cgit v1.1 From 7c572ac0cf5e8cd8e17f084bc6c253296cc42279 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= Date: Thu, 25 Sep 2008 13:25:30 +0100 Subject: tracing/ftrace: don't consume unhandled entries by boot tracer When the boot tracer can't handle an entry output, it returns 1. It should return 0 to relay on other output functions. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index c65ef8f..d5c9e2e 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -47,7 +47,7 @@ static void boot_trace_ctrl_update(struct trace_array *tr) static int initcall_print_line(struct trace_iterator *iter) { - int ret = 1; + int ret = 0; struct trace_entry *entry = iter->ent; struct boot_trace *it = &entry->field.initcall; struct trace_seq *s = &iter->seq; -- cgit v1.1 From 5aa60c6073456812251caf9177cb921b2de68f77 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:37 -0400 Subject: ftrace: give time for wakeup test to run It is possible that the testing thread in the ftrace wakeup test does not run before we stop the trace. This will cause the trace to fail since nothing will be in the buffers. This patch adds a small wait in the wakeup test to allow for the woken task to run and be traced. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_selftest.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 82db910..5ebd4b1 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -498,6 +498,9 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) wake_up_process(p); + /* give a little time to let the thread wake up */ + msleep(100); + /* stop the tracing. */ tr->ctrl = 0; trace->ctrl_update(tr); -- cgit v1.1 From 7a8e76a3829f1067b70f715771ff88baf2fbf3c3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:38 -0400 Subject: tracing: unified trace buffer This is a unified tracing buffer that implements a ring buffer that hopefully everyone will eventually be able to use. The events recorded into the buffer have the following structure: struct ring_buffer_event { u32 type:2, len:3, time_delta:27; u32 array[]; }; The minimum size of an event is 8 bytes. All events are 4 byte aligned inside the buffer. There are 4 types (all internal use for the ring buffer, only the data type is exported to the interface users). RINGBUF_TYPE_PADDING: this type is used to note extra space at the end of a buffer page. RINGBUF_TYPE_TIME_EXTENT: This type is used when the time between events is greater than the 27 bit delta can hold. We add another 32 bits, and record that in its own event (8 byte size). RINGBUF_TYPE_TIME_STAMP: (Not implemented yet). This will hold data to help keep the buffer timestamps in sync. RINGBUF_TYPE_DATA: The event actually holds user data. The "len" field is only three bits. Since the data must be 4 byte aligned, this field is shifted left by 2, giving a max length of 28 bytes. If the data load is greater than 28 bytes, the first array field holds the full length of the data load and the len field is set to zero. Example, data size of 7 bytes: type = RINGBUF_TYPE_DATA len = 2 time_delta: - array[0..1]: <7 bytes of data> <1 byte empty> This event is saved in 12 bytes of the buffer. An event with 82 bytes of data: type = RINGBUF_TYPE_DATA len = 0 time_delta: - array[0]: 84 (Note the alignment) array[1..14]: <82 bytes of data> <2 bytes empty> The above event is saved in 92 bytes (if my math is correct). 82 bytes of data, 2 bytes empty, 4 byte header, 4 byte length. Do not reference the above event struct directly. Use the following functions to gain access to the event table, since the ring_buffer_event structure may change in the future. ring_buffer_event_length(event): get the length of the event. This is the size of the memory used to record this event, and not the size of the data pay load. ring_buffer_time_delta(event): get the time delta of the event This returns the delta time stamp since the last event. Note: Even though this is in the header, there should be no reason to access this directly, accept for debugging. ring_buffer_event_data(event): get the data from the event This is the function to use to get the actual data from the event. Note, it is only a pointer to the data inside the buffer. This data must be copied to another location otherwise you risk it being written over in the buffer. ring_buffer_lock: A way to lock the entire buffer. ring_buffer_unlock: unlock the buffer. ring_buffer_alloc: create a new ring buffer. Can choose between overwrite or consumer/producer mode. Overwrite will overwrite old data, where as consumer producer will throw away new data if the consumer catches up with the producer. The consumer/producer is the default. ring_buffer_free: free the ring buffer. ring_buffer_resize: resize the buffer. Changes the size of each cpu buffer. Note, it is up to the caller to provide that the buffer is not being used while this is happening. This requirement may go away but do not count on it. ring_buffer_lock_reserve: locks the ring buffer and allocates an entry on the buffer to write to. ring_buffer_unlock_commit: unlocks the ring buffer and commits it to the buffer. ring_buffer_write: writes some data into the ring buffer. ring_buffer_peek: Look at a next item in the cpu buffer. ring_buffer_consume: get the next item in the cpu buffer and consume it. That is, this function increments the head pointer. ring_buffer_read_start: Start an iterator of a cpu buffer. For now, this disables the cpu buffer, until you issue a finish. This is just because we do not want the iterator to be overwritten. This restriction may change in the future. But note, this is used for static reading of a buffer which is usually done "after" a trace. Live readings would want to use the ring_buffer_consume above, which will not disable the ring buffer. ring_buffer_read_finish: Finishes the read iterator and reenables the ring buffer. ring_buffer_iter_peek: Look at the next item in the cpu iterator. ring_buffer_read: Read the iterator and increment it. ring_buffer_iter_reset: Reset the iterator to point to the beginning of the cpu buffer. ring_buffer_iter_empty: Returns true if the iterator is at the end of the cpu buffer. ring_buffer_size: returns the size in bytes of each cpu buffer. Note, the real size is this times the number of CPUs. ring_buffer_reset_cpu: Sets the cpu buffer to empty ring_buffer_reset: sets all cpu buffers to empty ring_buffer_swap_cpu: swaps a cpu buffer from one buffer with a cpu buffer of another buffer. This is handy when you want to take a snap shot of a running trace on just one cpu. Having a backup buffer, to swap with facilitates this. Ftrace max latencies use this. ring_buffer_empty: Returns true if the ring buffer is empty. ring_buffer_empty_cpu: Returns true if the cpu buffer is empty. ring_buffer_record_disable: disable all cpu buffers (read only) ring_buffer_record_disable_cpu: disable a single cpu buffer (read only) ring_buffer_record_enable: enable all cpu buffers. ring_buffer_record_enabl_cpu: enable a single cpu buffer. ring_buffer_entries: The number of entries in a ring buffer. ring_buffer_overruns: The number of entries removed due to writing wrap. ring_buffer_time_stamp: Get the time stamp used by the ring buffer ring_buffer_normalize_time_stamp: normalize the ring buffer time stamp into nanosecs. I still need to implement the GTOD feature. But we need support from the cpu frequency infrastructure. But this can be done at a later time without affecting the ring buffer interface. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 4 + kernel/trace/Makefile | 1 + kernel/trace/ring_buffer.c | 1672 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 1677 insertions(+) create mode 100644 kernel/trace/ring_buffer.c (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 4feb3c8..396aea1 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -18,9 +18,13 @@ config HAVE_FTRACE_MCOUNT_RECORD config TRACER_MAX_TRACE bool +config RING_BUFFER + bool + config TRACING bool select DEBUG_FS + select RING_BUFFER select STACKTRACE select TRACEPOINTS diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 35a07f7..a85dfba 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -11,6 +11,7 @@ obj-y += trace_selftest_dynamic.o endif obj-$(CONFIG_FTRACE) += libftrace.o +obj-$(CONFIG_RING_BUFFER) += ring_buffer.o obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c new file mode 100644 index 0000000..830a293 --- /dev/null +++ b/kernel/trace/ring_buffer.c @@ -0,0 +1,1672 @@ +/* + * Generic ring buffer + * + * Copyright (C) 2008 Steven Rostedt + */ +#include +#include +#include +#include +#include +#include +#include +#include /* used for sched_clock() (for now) */ +#include +#include +#include +#include + +/* Up this if you want to test the TIME_EXTENTS and normalization */ +#define DEBUG_SHIFT 0 + +/* FIXME!!! */ +u64 ring_buffer_time_stamp(int cpu) +{ + /* shift to debug/test normalization and TIME_EXTENTS */ + return sched_clock() << DEBUG_SHIFT; +} + +void ring_buffer_normalize_time_stamp(int cpu, u64 *ts) +{ + /* Just stupid testing the normalize function and deltas */ + *ts >>= DEBUG_SHIFT; +} + +#define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event)) +#define RB_ALIGNMENT_SHIFT 2 +#define RB_ALIGNMENT (1 << RB_ALIGNMENT_SHIFT) +#define RB_MAX_SMALL_DATA 28 + +enum { + RB_LEN_TIME_EXTEND = 8, + RB_LEN_TIME_STAMP = 16, +}; + +/* inline for ring buffer fast paths */ +static inline unsigned +rb_event_length(struct ring_buffer_event *event) +{ + unsigned length; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + /* undefined */ + return -1; + + case RINGBUF_TYPE_TIME_EXTEND: + return RB_LEN_TIME_EXTEND; + + case RINGBUF_TYPE_TIME_STAMP: + return RB_LEN_TIME_STAMP; + + case RINGBUF_TYPE_DATA: + if (event->len) + length = event->len << RB_ALIGNMENT_SHIFT; + else + length = event->array[0]; + return length + RB_EVNT_HDR_SIZE; + default: + BUG(); + } + /* not hit */ + return 0; +} + +/** + * ring_buffer_event_length - return the length of the event + * @event: the event to get the length of + */ +unsigned ring_buffer_event_length(struct ring_buffer_event *event) +{ + return rb_event_length(event); +} + +/* inline for ring buffer fast paths */ +static inline void * +rb_event_data(struct ring_buffer_event *event) +{ + BUG_ON(event->type != RINGBUF_TYPE_DATA); + /* If length is in len field, then array[0] has the data */ + if (event->len) + return (void *)&event->array[0]; + /* Otherwise length is in array[0] and array[1] has the data */ + return (void *)&event->array[1]; +} + +/** + * ring_buffer_event_data - return the data of the event + * @event: the event to get the data from + */ +void *ring_buffer_event_data(struct ring_buffer_event *event) +{ + return rb_event_data(event); +} + +#define for_each_buffer_cpu(buffer, cpu) \ + for_each_cpu_mask(cpu, buffer->cpumask) + +#define TS_SHIFT 27 +#define TS_MASK ((1ULL << TS_SHIFT) - 1) +#define TS_DELTA_TEST (~TS_MASK) + +/* + * This hack stolen from mm/slob.c. + * We can store per page timing information in the page frame of the page. + * Thanks to Peter Zijlstra for suggesting this idea. + */ +struct buffer_page { + union { + struct { + unsigned long flags; /* mandatory */ + atomic_t _count; /* mandatory */ + u64 time_stamp; /* page time stamp */ + unsigned size; /* size of page data */ + struct list_head list; /* list of free pages */ + }; + struct page page; + }; +}; + +/* + * We need to fit the time_stamp delta into 27 bits. + */ +static inline int test_time_stamp(u64 delta) +{ + if (delta & TS_DELTA_TEST) + return 1; + return 0; +} + +#define BUF_PAGE_SIZE PAGE_SIZE + +/* + * head_page == tail_page && head == tail then buffer is empty. + */ +struct ring_buffer_per_cpu { + int cpu; + struct ring_buffer *buffer; + spinlock_t lock; + struct lock_class_key lock_key; + struct list_head pages; + unsigned long head; /* read from head */ + unsigned long tail; /* write to tail */ + struct buffer_page *head_page; + struct buffer_page *tail_page; + unsigned long overrun; + unsigned long entries; + u64 write_stamp; + u64 read_stamp; + atomic_t record_disabled; +}; + +struct ring_buffer { + unsigned long size; + unsigned pages; + unsigned flags; + int cpus; + cpumask_t cpumask; + atomic_t record_disabled; + + struct mutex mutex; + + struct ring_buffer_per_cpu **buffers; +}; + +struct ring_buffer_iter { + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long head; + struct buffer_page *head_page; + u64 read_stamp; +}; + +#define RB_WARN_ON(buffer, cond) \ + if (unlikely(cond)) { \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + return -1; \ + } + +/** + * check_pages - integrity check of buffer pages + * @cpu_buffer: CPU buffer with pages to test + * + * As a safty measure we check to make sure the data pages have not + * been corrupted. + */ +static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + + RB_WARN_ON(cpu_buffer, head->next->prev != head); + RB_WARN_ON(cpu_buffer, head->prev->next != head); + + list_for_each_entry_safe(page, tmp, head, list) { + RB_WARN_ON(cpu_buffer, page->list.next->prev != &page->list); + RB_WARN_ON(cpu_buffer, page->list.prev->next != &page->list); + } + + return 0; +} + +static unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer) +{ + return cpu_buffer->head_page->size; +} + +static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, + unsigned nr_pages) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + unsigned long addr; + LIST_HEAD(pages); + unsigned i; + + for (i = 0; i < nr_pages; i++) { + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto free_pages; + page = (struct buffer_page *)virt_to_page(addr); + list_add(&page->list, &pages); + } + + list_splice(&pages, head); + + rb_check_pages(cpu_buffer); + + return 0; + + free_pages: + list_for_each_entry_safe(page, tmp, &pages, list) { + list_del_init(&page->list); + __free_page(&page->page); + } + return -ENOMEM; +} + +static struct ring_buffer_per_cpu * +rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int ret; + + cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!cpu_buffer) + return NULL; + + cpu_buffer->cpu = cpu; + cpu_buffer->buffer = buffer; + spin_lock_init(&cpu_buffer->lock); + INIT_LIST_HEAD(&cpu_buffer->pages); + + ret = rb_allocate_pages(cpu_buffer, buffer->pages); + if (ret < 0) + goto fail_free_buffer; + + cpu_buffer->head_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + cpu_buffer->tail_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + + return cpu_buffer; + + fail_free_buffer: + kfree(cpu_buffer); + return NULL; +} + +static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + + list_for_each_entry_safe(page, tmp, head, list) { + list_del_init(&page->list); + __free_page(&page->page); + } + kfree(cpu_buffer); +} + +/** + * ring_buffer_alloc - allocate a new ring_buffer + * @size: the size in bytes that is needed. + * @flags: attributes to set for the ring buffer. + * + * Currently the only flag that is available is the RB_FL_OVERWRITE + * flag. This flag means that the buffer will overwrite old data + * when the buffer wraps. If this flag is not set, the buffer will + * drop data when the tail hits the head. + */ +struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) +{ + struct ring_buffer *buffer; + int bsize; + int cpu; + + /* keep it in its own cache line */ + buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), + GFP_KERNEL); + if (!buffer) + return NULL; + + buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + buffer->flags = flags; + + /* need at least two pages */ + if (buffer->pages == 1) + buffer->pages++; + + buffer->cpumask = cpu_possible_map; + buffer->cpus = nr_cpu_ids; + + bsize = sizeof(void *) * nr_cpu_ids; + buffer->buffers = kzalloc(ALIGN(bsize, cache_line_size()), + GFP_KERNEL); + if (!buffer->buffers) + goto fail_free_buffer; + + for_each_buffer_cpu(buffer, cpu) { + buffer->buffers[cpu] = + rb_allocate_cpu_buffer(buffer, cpu); + if (!buffer->buffers[cpu]) + goto fail_free_buffers; + } + + mutex_init(&buffer->mutex); + + return buffer; + + fail_free_buffers: + for_each_buffer_cpu(buffer, cpu) { + if (buffer->buffers[cpu]) + rb_free_cpu_buffer(buffer->buffers[cpu]); + } + kfree(buffer->buffers); + + fail_free_buffer: + kfree(buffer); + return NULL; +} + +/** + * ring_buffer_free - free a ring buffer. + * @buffer: the buffer to free. + */ +void +ring_buffer_free(struct ring_buffer *buffer) +{ + int cpu; + + for_each_buffer_cpu(buffer, cpu) + rb_free_cpu_buffer(buffer->buffers[cpu]); + + kfree(buffer); +} + +static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer); + +static void +rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) +{ + struct buffer_page *page; + struct list_head *p; + unsigned i; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + for (i = 0; i < nr_pages; i++) { + BUG_ON(list_empty(&cpu_buffer->pages)); + p = cpu_buffer->pages.next; + page = list_entry(p, struct buffer_page, list); + list_del_init(&page->list); + __free_page(&page->page); + } + BUG_ON(list_empty(&cpu_buffer->pages)); + + rb_reset_cpu(cpu_buffer); + + rb_check_pages(cpu_buffer); + + atomic_dec(&cpu_buffer->record_disabled); + +} + +static void +rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, + struct list_head *pages, unsigned nr_pages) +{ + struct buffer_page *page; + struct list_head *p; + unsigned i; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + for (i = 0; i < nr_pages; i++) { + BUG_ON(list_empty(pages)); + p = pages->next; + page = list_entry(p, struct buffer_page, list); + list_del_init(&page->list); + list_add_tail(&page->list, &cpu_buffer->pages); + } + rb_reset_cpu(cpu_buffer); + + rb_check_pages(cpu_buffer); + + atomic_dec(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_resize - resize the ring buffer + * @buffer: the buffer to resize. + * @size: the new size. + * + * The tracer is responsible for making sure that the buffer is + * not being used while changing the size. + * Note: We may be able to change the above requirement by using + * RCU synchronizations. + * + * Minimum size is 2 * BUF_PAGE_SIZE. + * + * Returns -1 on failure. + */ +int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned nr_pages, rm_pages, new_pages; + struct buffer_page *page, *tmp; + unsigned long buffer_size; + unsigned long addr; + LIST_HEAD(pages); + int i, cpu; + + size = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + size *= BUF_PAGE_SIZE; + buffer_size = buffer->pages * BUF_PAGE_SIZE; + + /* we need a minimum of two pages */ + if (size < BUF_PAGE_SIZE * 2) + size = BUF_PAGE_SIZE * 2; + + if (size == buffer_size) + return size; + + mutex_lock(&buffer->mutex); + + nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + + if (size < buffer_size) { + + /* easy case, just free pages */ + BUG_ON(nr_pages >= buffer->pages); + + rm_pages = buffer->pages - nr_pages; + + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + rb_remove_pages(cpu_buffer, rm_pages); + } + goto out; + } + + /* + * This is a bit more difficult. We only want to add pages + * when we can allocate enough for all CPUs. We do this + * by allocating all the pages and storing them on a local + * link list. If we succeed in our allocation, then we + * add these pages to the cpu_buffers. Otherwise we just free + * them all and return -ENOMEM; + */ + BUG_ON(nr_pages <= buffer->pages); + new_pages = nr_pages - buffer->pages; + + for_each_buffer_cpu(buffer, cpu) { + for (i = 0; i < new_pages; i++) { + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto free_pages; + page = (struct buffer_page *)virt_to_page(addr); + list_add(&page->list, &pages); + } + } + + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + rb_insert_pages(cpu_buffer, &pages, new_pages); + } + + BUG_ON(!list_empty(&pages)); + + out: + buffer->pages = nr_pages; + mutex_unlock(&buffer->mutex); + + return size; + + free_pages: + list_for_each_entry_safe(page, tmp, &pages, list) { + list_del_init(&page->list); + __free_page(&page->page); + } + return -ENOMEM; +} + +static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) +{ + return cpu_buffer->head_page == cpu_buffer->tail_page && + cpu_buffer->head == cpu_buffer->tail; +} + +static inline int rb_null_event(struct ring_buffer_event *event) +{ + return event->type == RINGBUF_TYPE_PADDING; +} + +static inline void *rb_page_index(struct buffer_page *page, unsigned index) +{ + void *addr = page_address(&page->page); + + return addr + index; +} + +static inline struct ring_buffer_event * +rb_head_event(struct ring_buffer_per_cpu *cpu_buffer) +{ + return rb_page_index(cpu_buffer->head_page, + cpu_buffer->head); +} + +static inline struct ring_buffer_event * +rb_iter_head_event(struct ring_buffer_iter *iter) +{ + return rb_page_index(iter->head_page, + iter->head); +} + +/* + * When the tail hits the head and the buffer is in overwrite mode, + * the head jumps to the next page and all content on the previous + * page is discarded. But before doing so, we update the overrun + * variable of the buffer. + */ +static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct ring_buffer_event *event; + unsigned long head; + + for (head = 0; head < rb_head_size(cpu_buffer); + head += rb_event_length(event)) { + + event = rb_page_index(cpu_buffer->head_page, head); + BUG_ON(rb_null_event(event)); + /* Only count data entries */ + if (event->type != RINGBUF_TYPE_DATA) + continue; + cpu_buffer->overrun++; + cpu_buffer->entries--; + } +} + +static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer, + struct buffer_page **page) +{ + struct list_head *p = (*page)->list.next; + + if (p == &cpu_buffer->pages) + p = p->next; + + *page = list_entry(p, struct buffer_page, list); +} + +static inline void +rb_add_stamp(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) +{ + cpu_buffer->tail_page->time_stamp = *ts; + cpu_buffer->write_stamp = *ts; +} + +static void rb_reset_read_page(struct ring_buffer_per_cpu *cpu_buffer) +{ + cpu_buffer->read_stamp = cpu_buffer->head_page->time_stamp; + cpu_buffer->head = 0; +} + +static void +rb_reset_iter_read_page(struct ring_buffer_iter *iter) +{ + iter->read_stamp = iter->head_page->time_stamp; + iter->head = 0; +} + +/** + * ring_buffer_update_event - update event type and data + * @event: the even to update + * @type: the type of event + * @length: the size of the event field in the ring buffer + * + * Update the type and data fields of the event. The length + * is the actual size that is written to the ring buffer, + * and with this, we can determine what to place into the + * data field. + */ +static inline void +rb_update_event(struct ring_buffer_event *event, + unsigned type, unsigned length) +{ + event->type = type; + + switch (type) { + + case RINGBUF_TYPE_PADDING: + break; + + case RINGBUF_TYPE_TIME_EXTEND: + event->len = + (RB_LEN_TIME_EXTEND + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + + case RINGBUF_TYPE_TIME_STAMP: + event->len = + (RB_LEN_TIME_STAMP + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + + case RINGBUF_TYPE_DATA: + length -= RB_EVNT_HDR_SIZE; + if (length > RB_MAX_SMALL_DATA) { + event->len = 0; + event->array[0] = length; + } else + event->len = + (length + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + default: + BUG(); + } +} + +static inline unsigned rb_calculate_event_length(unsigned length) +{ + struct ring_buffer_event event; /* Used only for sizeof array */ + + /* zero length can cause confusions */ + if (!length) + length = 1; + + if (length > RB_MAX_SMALL_DATA) + length += sizeof(event.array[0]); + + length += RB_EVNT_HDR_SIZE; + length = ALIGN(length, RB_ALIGNMENT); + + return length; +} + +static struct ring_buffer_event * +__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, + unsigned type, unsigned long length, u64 *ts) +{ + struct buffer_page *head_page, *tail_page; + unsigned long tail; + struct ring_buffer *buffer = cpu_buffer->buffer; + struct ring_buffer_event *event; + + tail_page = cpu_buffer->tail_page; + head_page = cpu_buffer->head_page; + tail = cpu_buffer->tail; + + if (tail + length > BUF_PAGE_SIZE) { + struct buffer_page *next_page = tail_page; + + rb_inc_page(cpu_buffer, &next_page); + + if (next_page == head_page) { + if (!(buffer->flags & RB_FL_OVERWRITE)) + return NULL; + + /* count overflows */ + rb_update_overflow(cpu_buffer); + + rb_inc_page(cpu_buffer, &head_page); + cpu_buffer->head_page = head_page; + rb_reset_read_page(cpu_buffer); + } + + if (tail != BUF_PAGE_SIZE) { + event = rb_page_index(tail_page, tail); + /* page padding */ + event->type = RINGBUF_TYPE_PADDING; + } + + tail_page->size = tail; + tail_page = next_page; + tail_page->size = 0; + tail = 0; + cpu_buffer->tail_page = tail_page; + cpu_buffer->tail = tail; + rb_add_stamp(cpu_buffer, ts); + } + + BUG_ON(tail + length > BUF_PAGE_SIZE); + + event = rb_page_index(tail_page, tail); + rb_update_event(event, type, length); + + return event; +} + +static int +rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, + u64 *ts, u64 *delta) +{ + struct ring_buffer_event *event; + static int once; + + if (unlikely(*delta > (1ULL << 59) && !once++)) { + printk(KERN_WARNING "Delta way too big! %llu" + " ts=%llu write stamp = %llu\n", + *delta, *ts, cpu_buffer->write_stamp); + WARN_ON(1); + } + + /* + * The delta is too big, we to add a + * new timestamp. + */ + event = __rb_reserve_next(cpu_buffer, + RINGBUF_TYPE_TIME_EXTEND, + RB_LEN_TIME_EXTEND, + ts); + if (!event) + return -1; + + /* check to see if we went to the next page */ + if (cpu_buffer->tail) { + /* Still on same page, update timestamp */ + event->time_delta = *delta & TS_MASK; + event->array[0] = *delta >> TS_SHIFT; + /* commit the time event */ + cpu_buffer->tail += + rb_event_length(event); + cpu_buffer->write_stamp = *ts; + *delta = 0; + } + + return 0; +} + +static struct ring_buffer_event * +rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, + unsigned type, unsigned long length) +{ + struct ring_buffer_event *event; + u64 ts, delta; + + ts = ring_buffer_time_stamp(cpu_buffer->cpu); + + if (cpu_buffer->tail) { + delta = ts - cpu_buffer->write_stamp; + + if (test_time_stamp(delta)) { + int ret; + + ret = rb_add_time_stamp(cpu_buffer, &ts, &delta); + if (ret < 0) + return NULL; + } + } else { + rb_add_stamp(cpu_buffer, &ts); + delta = 0; + } + + event = __rb_reserve_next(cpu_buffer, type, length, &ts); + if (!event) + return NULL; + + /* If the reserve went to the next page, our delta is zero */ + if (!cpu_buffer->tail) + delta = 0; + + event->time_delta = delta; + + return event; +} + +/** + * ring_buffer_lock_reserve - reserve a part of the buffer + * @buffer: the ring buffer to reserve from + * @length: the length of the data to reserve (excluding event header) + * @flags: a pointer to save the interrupt flags + * + * Returns a reseverd event on the ring buffer to copy directly to. + * The user of this interface will need to get the body to write into + * and can use the ring_buffer_event_data() interface. + * + * The length is the length of the data needed, not the event length + * which also includes the event header. + * + * Must be paired with ring_buffer_unlock_commit, unless NULL is returned. + * If NULL is returned, then nothing has been allocated or locked. + */ +struct ring_buffer_event * +ring_buffer_lock_reserve(struct ring_buffer *buffer, + unsigned long length, + unsigned long *flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + int cpu; + + if (atomic_read(&buffer->record_disabled)) + return NULL; + + raw_local_irq_save(*flags); + cpu = raw_smp_processor_id(); + + if (!cpu_isset(cpu, buffer->cpumask)) + goto out_irq; + + cpu_buffer = buffer->buffers[cpu]; + spin_lock(&cpu_buffer->lock); + + if (atomic_read(&cpu_buffer->record_disabled)) + goto no_record; + + length = rb_calculate_event_length(length); + if (length > BUF_PAGE_SIZE) + return NULL; + + event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length); + if (!event) + goto no_record; + + return event; + + no_record: + spin_unlock(&cpu_buffer->lock); + out_irq: + local_irq_restore(*flags); + return NULL; +} + +static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + cpu_buffer->tail += rb_event_length(event); + cpu_buffer->tail_page->size = cpu_buffer->tail; + cpu_buffer->write_stamp += event->time_delta; + cpu_buffer->entries++; +} + +/** + * ring_buffer_unlock_commit - commit a reserved + * @buffer: The buffer to commit to + * @event: The event pointer to commit. + * @flags: the interrupt flags received from ring_buffer_lock_reserve. + * + * This commits the data to the ring buffer, and releases any locks held. + * + * Must be paired with ring_buffer_lock_reserve. + */ +int ring_buffer_unlock_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu = raw_smp_processor_id(); + + cpu_buffer = buffer->buffers[cpu]; + + assert_spin_locked(&cpu_buffer->lock); + + rb_commit(cpu_buffer, event); + + spin_unlock(&cpu_buffer->lock); + raw_local_irq_restore(flags); + + return 0; +} + +/** + * ring_buffer_write - write data to the buffer without reserving + * @buffer: The ring buffer to write to. + * @length: The length of the data being written (excluding the event header) + * @data: The data to write to the buffer. + * + * This is like ring_buffer_lock_reserve and ring_buffer_unlock_commit as + * one function. If you already have the data to write to the buffer, it + * may be easier to simply call this function. + * + * Note, like ring_buffer_lock_reserve, the length is the length of the data + * and not the length of the event which would hold the header. + */ +int ring_buffer_write(struct ring_buffer *buffer, + unsigned long length, + void *data) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + unsigned long event_length, flags; + void *body; + int ret = -EBUSY; + int cpu; + + if (atomic_read(&buffer->record_disabled)) + return -EBUSY; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + + if (!cpu_isset(cpu, buffer->cpumask)) + goto out_irq; + + cpu_buffer = buffer->buffers[cpu]; + spin_lock(&cpu_buffer->lock); + + if (atomic_read(&cpu_buffer->record_disabled)) + goto out; + + event_length = rb_calculate_event_length(length); + event = rb_reserve_next_event(cpu_buffer, + RINGBUF_TYPE_DATA, event_length); + if (!event) + goto out; + + body = rb_event_data(event); + + memcpy(body, data, length); + + rb_commit(cpu_buffer, event); + + ret = 0; + out: + spin_unlock(&cpu_buffer->lock); + out_irq: + local_irq_restore(flags); + + return ret; +} + +/** + * ring_buffer_lock - lock the ring buffer + * @buffer: The ring buffer to lock + * @flags: The place to store the interrupt flags + * + * This locks all the per CPU buffers. + * + * Must be unlocked by ring_buffer_unlock. + */ +void ring_buffer_lock(struct ring_buffer *buffer, unsigned long *flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + local_irq_save(*flags); + + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + spin_lock(&cpu_buffer->lock); + } +} + +/** + * ring_buffer_unlock - unlock a locked buffer + * @buffer: The locked buffer to unlock + * @flags: The interrupt flags received by ring_buffer_lock + */ +void ring_buffer_unlock(struct ring_buffer *buffer, unsigned long flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + for (cpu = buffer->cpus - 1; cpu >= 0; cpu--) { + if (!cpu_isset(cpu, buffer->cpumask)) + continue; + cpu_buffer = buffer->buffers[cpu]; + spin_unlock(&cpu_buffer->lock); + } + + local_irq_restore(flags); +} + +/** + * ring_buffer_record_disable - stop all writes into the buffer + * @buffer: The ring buffer to stop writes to. + * + * This prevents all writes to the buffer. Any attempt to write + * to the buffer after this will fail and return NULL. + * + * The caller should call synchronize_sched() after this. + */ +void ring_buffer_record_disable(struct ring_buffer *buffer) +{ + atomic_inc(&buffer->record_disabled); +} + +/** + * ring_buffer_record_enable - enable writes to the buffer + * @buffer: The ring buffer to enable writes + * + * Note, multiple disables will need the same number of enables + * to truely enable the writing (much like preempt_disable). + */ +void ring_buffer_record_enable(struct ring_buffer *buffer) +{ + atomic_dec(&buffer->record_disabled); +} + +/** + * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer + * @buffer: The ring buffer to stop writes to. + * @cpu: The CPU buffer to stop + * + * This prevents all writes to the buffer. Any attempt to write + * to the buffer after this will fail and return NULL. + * + * The caller should call synchronize_sched() after this. + */ +void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + cpu_buffer = buffer->buffers[cpu]; + atomic_inc(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_record_enable_cpu - enable writes to the buffer + * @buffer: The ring buffer to enable writes + * @cpu: The CPU to enable. + * + * Note, multiple disables will need the same number of enables + * to truely enable the writing (much like preempt_disable). + */ +void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + cpu_buffer = buffer->buffers[cpu]; + atomic_dec(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_entries_cpu - get the number of entries in a cpu buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the entries from. + */ +unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->entries; +} + +/** + * ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the number of overruns from + */ +unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->overrun; +} + +/** + * ring_buffer_entries - get the number of entries in a buffer + * @buffer: The ring buffer + * + * Returns the total number of entries in the ring buffer + * (all CPU entries) + */ +unsigned long ring_buffer_entries(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long entries = 0; + int cpu; + + /* if you care about this being correct, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + entries += cpu_buffer->entries; + } + + return entries; +} + +/** + * ring_buffer_overrun_cpu - get the number of overruns in buffer + * @buffer: The ring buffer + * + * Returns the total number of overruns in the ring buffer + * (all CPU entries) + */ +unsigned long ring_buffer_overruns(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long overruns = 0; + int cpu; + + /* if you care about this being correct, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + overruns += cpu_buffer->overrun; + } + + return overruns; +} + +/** + * ring_buffer_iter_reset - reset an iterator + * @iter: The iterator to reset + * + * Resets the iterator, so that it will start from the beginning + * again. + */ +void ring_buffer_iter_reset(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + iter->head_page = cpu_buffer->head_page; + iter->head = cpu_buffer->head; + rb_reset_iter_read_page(iter); +} + +/** + * ring_buffer_iter_empty - check if an iterator has no more to read + * @iter: The iterator to check + */ +int ring_buffer_iter_empty(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + cpu_buffer = iter->cpu_buffer; + + return iter->head_page == cpu_buffer->tail_page && + iter->head == cpu_buffer->tail; +} + +static void +rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + u64 delta; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + return; + + case RINGBUF_TYPE_TIME_EXTEND: + delta = event->array[0]; + delta <<= TS_SHIFT; + delta += event->time_delta; + cpu_buffer->read_stamp += delta; + return; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + return; + + case RINGBUF_TYPE_DATA: + cpu_buffer->read_stamp += event->time_delta; + return; + + default: + BUG(); + } + return; +} + +static void +rb_update_iter_read_stamp(struct ring_buffer_iter *iter, + struct ring_buffer_event *event) +{ + u64 delta; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + return; + + case RINGBUF_TYPE_TIME_EXTEND: + delta = event->array[0]; + delta <<= TS_SHIFT; + delta += event->time_delta; + iter->read_stamp += delta; + return; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + return; + + case RINGBUF_TYPE_DATA: + iter->read_stamp += event->time_delta; + return; + + default: + BUG(); + } + return; +} + +static void rb_advance_head(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct ring_buffer_event *event; + unsigned length; + + /* + * Check if we are at the end of the buffer. + */ + if (cpu_buffer->head >= cpu_buffer->head_page->size) { + BUG_ON(cpu_buffer->head_page == cpu_buffer->tail_page); + rb_inc_page(cpu_buffer, &cpu_buffer->head_page); + rb_reset_read_page(cpu_buffer); + return; + } + + event = rb_head_event(cpu_buffer); + + if (event->type == RINGBUF_TYPE_DATA) + cpu_buffer->entries--; + + length = rb_event_length(event); + + /* + * This should not be called to advance the header if we are + * at the tail of the buffer. + */ + BUG_ON((cpu_buffer->head_page == cpu_buffer->tail_page) && + (cpu_buffer->head + length > cpu_buffer->tail)); + + rb_update_read_stamp(cpu_buffer, event); + + cpu_buffer->head += length; + + /* check for end of page */ + if ((cpu_buffer->head >= cpu_buffer->head_page->size) && + (cpu_buffer->head_page != cpu_buffer->tail_page)) + rb_advance_head(cpu_buffer); +} + +static void rb_advance_iter(struct ring_buffer_iter *iter) +{ + struct ring_buffer *buffer; + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + unsigned length; + + cpu_buffer = iter->cpu_buffer; + buffer = cpu_buffer->buffer; + + /* + * Check if we are at the end of the buffer. + */ + if (iter->head >= iter->head_page->size) { + BUG_ON(iter->head_page == cpu_buffer->tail_page); + rb_inc_page(cpu_buffer, &iter->head_page); + rb_reset_iter_read_page(iter); + return; + } + + event = rb_iter_head_event(iter); + + length = rb_event_length(event); + + /* + * This should not be called to advance the header if we are + * at the tail of the buffer. + */ + BUG_ON((iter->head_page == cpu_buffer->tail_page) && + (iter->head + length > cpu_buffer->tail)); + + rb_update_iter_read_stamp(iter, event); + + iter->head += length; + + /* check for end of page padding */ + if ((iter->head >= iter->head_page->size) && + (iter->head_page != cpu_buffer->tail_page)) + rb_advance_iter(iter); +} + +/** + * ring_buffer_peek - peek at the next event to be read + * @buffer: The ring buffer to read + * @cpu: The cpu to peak at + * @ts: The timestamp counter of this event. + * + * This will return the event that will be read next, but does + * not consume the data. + */ +struct ring_buffer_event * +ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + + again: + if (rb_per_cpu_empty(cpu_buffer)) + return NULL; + + event = rb_head_event(cpu_buffer); + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + rb_inc_page(cpu_buffer, &cpu_buffer->head_page); + rb_reset_read_page(cpu_buffer); + goto again; + + case RINGBUF_TYPE_TIME_EXTEND: + /* Internal data, OK to advance */ + rb_advance_head(cpu_buffer); + goto again; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + rb_advance_head(cpu_buffer); + goto again; + + case RINGBUF_TYPE_DATA: + if (ts) { + *ts = cpu_buffer->read_stamp + event->time_delta; + ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts); + } + return event; + + default: + BUG(); + } + + return NULL; +} + +/** + * ring_buffer_iter_peek - peek at the next event to be read + * @iter: The ring buffer iterator + * @ts: The timestamp counter of this event. + * + * This will return the event that will be read next, but does + * not increment the iterator. + */ +struct ring_buffer_event * +ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) +{ + struct ring_buffer *buffer; + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + + if (ring_buffer_iter_empty(iter)) + return NULL; + + cpu_buffer = iter->cpu_buffer; + buffer = cpu_buffer->buffer; + + again: + if (rb_per_cpu_empty(cpu_buffer)) + return NULL; + + event = rb_iter_head_event(iter); + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + rb_inc_page(cpu_buffer, &iter->head_page); + rb_reset_iter_read_page(iter); + goto again; + + case RINGBUF_TYPE_TIME_EXTEND: + /* Internal data, OK to advance */ + rb_advance_iter(iter); + goto again; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + rb_advance_iter(iter); + goto again; + + case RINGBUF_TYPE_DATA: + if (ts) { + *ts = iter->read_stamp + event->time_delta; + ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts); + } + return event; + + default: + BUG(); + } + + return NULL; +} + +/** + * ring_buffer_consume - return an event and consume it + * @buffer: The ring buffer to get the next event from + * + * Returns the next event in the ring buffer, and that event is consumed. + * Meaning, that sequential reads will keep returning a different event, + * and eventually empty the ring buffer if the producer is slower. + */ +struct ring_buffer_event * +ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + event = ring_buffer_peek(buffer, cpu, ts); + if (!event) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + rb_advance_head(cpu_buffer); + + return event; +} + +/** + * ring_buffer_read_start - start a non consuming read of the buffer + * @buffer: The ring buffer to read from + * @cpu: The cpu buffer to iterate over + * + * This starts up an iteration through the buffer. It also disables + * the recording to the buffer until the reading is finished. + * This prevents the reading from being corrupted. This is not + * a consuming read, so a producer is not expected. + * + * Must be paired with ring_buffer_finish. + */ +struct ring_buffer_iter * +ring_buffer_read_start(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_iter *iter; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + iter = kmalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + + iter->cpu_buffer = cpu_buffer; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + spin_lock(&cpu_buffer->lock); + iter->head = cpu_buffer->head; + iter->head_page = cpu_buffer->head_page; + rb_reset_iter_read_page(iter); + spin_unlock(&cpu_buffer->lock); + + return iter; +} + +/** + * ring_buffer_finish - finish reading the iterator of the buffer + * @iter: The iterator retrieved by ring_buffer_start + * + * This re-enables the recording to the buffer, and frees the + * iterator. + */ +void +ring_buffer_read_finish(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + atomic_dec(&cpu_buffer->record_disabled); + kfree(iter); +} + +/** + * ring_buffer_read - read the next item in the ring buffer by the iterator + * @iter: The ring buffer iterator + * @ts: The time stamp of the event read. + * + * This reads the next event in the ring buffer and increments the iterator. + */ +struct ring_buffer_event * +ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts) +{ + struct ring_buffer_event *event; + + event = ring_buffer_iter_peek(iter, ts); + if (!event) + return NULL; + + rb_advance_iter(iter); + + return event; +} + +/** + * ring_buffer_size - return the size of the ring buffer (in bytes) + * @buffer: The ring buffer. + */ +unsigned long ring_buffer_size(struct ring_buffer *buffer) +{ + return BUF_PAGE_SIZE * buffer->pages; +} + +static void +rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) +{ + cpu_buffer->head_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + cpu_buffer->tail_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + + cpu_buffer->head = cpu_buffer->tail = 0; + cpu_buffer->overrun = 0; + cpu_buffer->entries = 0; +} + +/** + * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer + * @buffer: The ring buffer to reset a per cpu buffer of + * @cpu: The CPU buffer to be reset + */ +void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu]; + unsigned long flags; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + raw_local_irq_save(flags); + spin_lock(&cpu_buffer->lock); + + rb_reset_cpu(cpu_buffer); + + spin_unlock(&cpu_buffer->lock); + raw_local_irq_restore(flags); +} + +/** + * ring_buffer_reset - reset a ring buffer + * @buffer: The ring buffer to reset all cpu buffers + */ +void ring_buffer_reset(struct ring_buffer *buffer) +{ + unsigned long flags; + int cpu; + + ring_buffer_lock(buffer, &flags); + + for_each_buffer_cpu(buffer, cpu) + rb_reset_cpu(buffer->buffers[cpu]); + + ring_buffer_unlock(buffer, flags); +} + +/** + * rind_buffer_empty - is the ring buffer empty? + * @buffer: The ring buffer to test + */ +int ring_buffer_empty(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + /* yes this is racy, but if you don't like the race, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + if (!rb_per_cpu_empty(cpu_buffer)) + return 0; + } + return 1; +} + +/** + * ring_buffer_empty_cpu - is a cpu buffer of a ring buffer empty? + * @buffer: The ring buffer + * @cpu: The CPU buffer to test + */ +int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 1; + + cpu_buffer = buffer->buffers[cpu]; + return rb_per_cpu_empty(cpu_buffer); +} + +/** + * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers + * @buffer_a: One buffer to swap with + * @buffer_b: The other buffer to swap with + * + * This function is useful for tracers that want to take a "snapshot" + * of a CPU buffer and has another back up buffer lying around. + * it is expected that the tracer handles the cpu buffer not being + * used at the moment. + */ +int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, + struct ring_buffer *buffer_b, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer_a; + struct ring_buffer_per_cpu *cpu_buffer_b; + + if (!cpu_isset(cpu, buffer_a->cpumask) || + !cpu_isset(cpu, buffer_b->cpumask)) + return -EINVAL; + + /* At least make sure the two buffers are somewhat the same */ + if (buffer_a->size != buffer_b->size || + buffer_a->pages != buffer_b->pages) + return -EINVAL; + + cpu_buffer_a = buffer_a->buffers[cpu]; + cpu_buffer_b = buffer_b->buffers[cpu]; + + /* + * We can't do a synchronize_sched here because this + * function can be called in atomic context. + * Normally this will be called from the same CPU as cpu. + * If not it's up to the caller to protect this. + */ + atomic_inc(&cpu_buffer_a->record_disabled); + atomic_inc(&cpu_buffer_b->record_disabled); + + buffer_a->buffers[cpu] = cpu_buffer_b; + buffer_b->buffers[cpu] = cpu_buffer_a; + + cpu_buffer_b->buffer = buffer_a; + cpu_buffer_a->buffer = buffer_b; + + atomic_dec(&cpu_buffer_a->record_disabled); + atomic_dec(&cpu_buffer_b->record_disabled); + + return 0; +} + -- cgit v1.1 From a7b1374333407f409cf8df7e623b12490f073c84 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:39 -0400 Subject: ring_buffer: add paranoid check for buffer page If for some strange reason the buffer_page gets bigger, or the page struct gets smaller, I want to know this ASAP. The best way is to not let the kernel compile. This patch adds code to test the size of the struct buffer_page against the page struct and will cause compile issues if the buffer_page ever gets bigger than the page struct. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 830a293..95ca933 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -289,6 +289,12 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) kfree(cpu_buffer); } +/* + * Causes compile errors if the struct buffer_page gets bigger + * than the struct page. + */ +extern int ring_buffer_page_too_big(void); + /** * ring_buffer_alloc - allocate a new ring_buffer * @size: the size in bytes that is needed. @@ -305,6 +311,11 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) int bsize; int cpu; + /* Paranoid! Optimizes out when all is well */ + if (sizeof(struct buffer_page) > sizeof(struct page)) + ring_buffer_page_too_big(); + + /* keep it in its own cache line */ buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), GFP_KERNEL); -- cgit v1.1 From ed56829cb3195de499f97fa6108fe9134319bae6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:40 -0400 Subject: ring_buffer: reset buffer page when freeing Mathieu Desnoyers pointed out that the freeing of the page frame needs to be reset otherwise we might trigger BUG_ON in the page free code. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 95ca933..cfa7113 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -128,6 +128,17 @@ struct buffer_page { }; /* + * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing + * this issue out. + */ +static inline void free_buffer_page(struct buffer_page *bpage) +{ + reset_page_mapcount(&bpage->page); + bpage->page.mapping = NULL; + __free_page(&bpage->page); +} + +/* * We need to fit the time_stamp delta into 27 bits. */ static inline int test_time_stamp(u64 delta) @@ -240,7 +251,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, free_pages: list_for_each_entry_safe(page, tmp, &pages, list) { list_del_init(&page->list); - __free_page(&page->page); + free_buffer_page(page); } return -ENOMEM; } @@ -284,7 +295,7 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) list_for_each_entry_safe(page, tmp, head, list) { list_del_init(&page->list); - __free_page(&page->page); + free_buffer_page(page); } kfree(cpu_buffer); } @@ -393,7 +404,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) p = cpu_buffer->pages.next; page = list_entry(p, struct buffer_page, list); list_del_init(&page->list); - __free_page(&page->page); + free_buffer_page(page); } BUG_ON(list_empty(&cpu_buffer->pages)); @@ -520,7 +531,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) free_pages: list_for_each_entry_safe(page, tmp, &pages, list) { list_del_init(&page->list); - __free_page(&page->page); + free_buffer_page(page); } return -ENOMEM; } -- cgit v1.1 From 3928a8a2d98081d1bc3c0a84a2d70e29b90ecf1c Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:41 -0400 Subject: ftrace: make work with new ring buffer This patch ports ftrace over to the new ring buffer. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 932 ++++++++++---------------------------- kernel/trace/trace.h | 22 +- kernel/trace/trace_boot.c | 16 +- kernel/trace/trace_functions.c | 2 +- kernel/trace/trace_irqsoff.c | 6 +- kernel/trace/trace_mmiotrace.c | 40 +- kernel/trace/trace_nop.c | 2 +- kernel/trace/trace_sched_switch.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 60 +-- kernel/trace/trace_sysprof.c | 2 +- 11 files changed, 288 insertions(+), 798 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6ada059..ef80793 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -33,25 +33,22 @@ #include #include +#include #include "trace.h" +#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE) + unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; unsigned long __read_mostly tracing_thresh; -static unsigned long __read_mostly tracing_nr_buffers; static cpumask_t __read_mostly tracing_buffer_mask; #define for_each_tracing_cpu(cpu) \ for_each_cpu_mask(cpu, tracing_buffer_mask) -static int trace_alloc_page(void); -static int trace_free_page(void); - static int tracing_disabled = 1; -static unsigned long tracing_pages_allocated; - long ns2usecs(cycle_t nsec) { @@ -62,7 +59,9 @@ ns2usecs(cycle_t nsec) cycle_t ftrace_now(int cpu) { - return cpu_clock(cpu); + u64 ts = ring_buffer_time_stamp(cpu); + ring_buffer_normalize_time_stamp(cpu, &ts); + return ts; } /* @@ -102,18 +101,18 @@ static int tracer_enabled = 1; int ftrace_function_enabled; /* - * trace_nr_entries is the number of entries that is allocated - * for a buffer. Note, the number of entries is always rounded - * to ENTRIES_PER_PAGE. + * trace_buf_size is the size in bytes that is allocated + * for a buffer. Note, the number of bytes is always rounded + * to page size. * * This number is purposely set to a low number of 16384. * If the dump on oops happens, it will be much appreciated * to not have to wait for all that output. Anyway this can be * boot time and run time configurable. */ -#define TRACE_ENTRIES_DEFAULT 16384UL +#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ -static unsigned long trace_nr_entries = TRACE_ENTRIES_DEFAULT; +static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; /* trace_types holds a link list of available tracers. */ static struct tracer *trace_types __read_mostly; @@ -158,23 +157,21 @@ void trace_wake_up(void) wake_up(&trace_wait); } -#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) - -static int __init set_nr_entries(char *str) +static int __init set_buf_size(char *str) { - unsigned long nr_entries; + unsigned long buf_size; int ret; if (!str) return 0; - ret = strict_strtoul(str, 0, &nr_entries); + ret = strict_strtoul(str, 0, &buf_size); /* nr_entries can not be zero */ - if (ret < 0 || nr_entries == 0) + if (ret < 0 || buf_size == 0) return 0; - trace_nr_entries = nr_entries; + trace_buf_size = buf_size; return 1; } -__setup("trace_entries=", set_nr_entries); +__setup("trace_buf_size=", set_buf_size); unsigned long nsecs_to_usecs(unsigned long nsecs) { @@ -243,54 +240,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) tracing_record_cmdline(current); } -#define CHECK_COND(cond) \ - if (unlikely(cond)) { \ - tracing_disabled = 1; \ - WARN_ON(1); \ - return -1; \ - } - -/** - * check_pages - integrity check of trace buffers - * - * As a safty measure we check to make sure the data pages have not - * been corrupted. - */ -int check_pages(struct trace_array_cpu *data) -{ - struct page *page, *tmp; - - CHECK_COND(data->trace_pages.next->prev != &data->trace_pages); - CHECK_COND(data->trace_pages.prev->next != &data->trace_pages); - - list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { - CHECK_COND(page->lru.next->prev != &page->lru); - CHECK_COND(page->lru.prev->next != &page->lru); - } - - return 0; -} - -/** - * head_page - page address of the first page in per_cpu buffer. - * - * head_page returns the page address of the first page in - * a per_cpu buffer. This also preforms various consistency - * checks to make sure the buffer has not been corrupted. - */ -void *head_page(struct trace_array_cpu *data) -{ - struct page *page; - - if (list_empty(&data->trace_pages)) - return NULL; - - page = list_entry(data->trace_pages.next, struct page, lru); - BUG_ON(&page->lru == &data->trace_pages); - - return page_address(page); -} - /** * trace_seq_printf - sequence printing of trace information * @s: trace sequence descriptor @@ -437,34 +386,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s) trace_seq_reset(s); } -/* - * flip the trace buffers between two trace descriptors. - * This usually is the buffers between the global_trace and - * the max_tr to record a snapshot of a current trace. - * - * The ftrace_max_lock must be held. - */ -static void -flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) -{ - struct list_head flip_pages; - - INIT_LIST_HEAD(&flip_pages); - - memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, - sizeof(struct trace_array_cpu) - - offsetof(struct trace_array_cpu, trace_head_idx)); - - check_pages(tr1); - check_pages(tr2); - list_splice_init(&tr1->trace_pages, &flip_pages); - list_splice_init(&tr2->trace_pages, &tr1->trace_pages); - list_splice_init(&flip_pages, &tr2->trace_pages); - BUG_ON(!list_empty(&flip_pages)); - check_pages(tr1); - check_pages(tr2); -} - /** * update_max_tr - snapshot all trace buffers from global_trace to max_tr * @tr: tracer @@ -477,17 +398,15 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct trace_array_cpu *data; - int i; + struct ring_buffer *buf = tr->buffer; WARN_ON_ONCE(!irqs_disabled()); __raw_spin_lock(&ftrace_max_lock); - /* clear out all the previous traces */ - for_each_tracing_cpu(i) { - data = tr->data[i]; - flip_trace(max_tr.data[i], data); - tracing_reset(data); - } + + tr->buffer = max_tr.buffer; + max_tr.buffer = buf; + + ring_buffer_reset(tr->buffer); __update_max_tr(tr, tsk, cpu); __raw_spin_unlock(&ftrace_max_lock); @@ -504,16 +423,15 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) void update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct trace_array_cpu *data = tr->data[cpu]; - int i; + int ret; WARN_ON_ONCE(!irqs_disabled()); __raw_spin_lock(&ftrace_max_lock); - for_each_tracing_cpu(i) - tracing_reset(max_tr.data[i]); - flip_trace(max_tr.data[cpu], data); - tracing_reset(data); + ring_buffer_reset(max_tr.buffer); + ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); + + WARN_ON_ONCE(ret); __update_max_tr(tr, tsk, cpu); __raw_spin_unlock(&ftrace_max_lock); @@ -550,7 +468,6 @@ int register_tracer(struct tracer *type) #ifdef CONFIG_FTRACE_STARTUP_TEST if (type->selftest) { struct tracer *saved_tracer = current_trace; - struct trace_array_cpu *data; struct trace_array *tr = &global_trace; int saved_ctrl = tr->ctrl; int i; @@ -562,10 +479,7 @@ int register_tracer(struct tracer *type) * If we fail, we do not register this tracer. */ for_each_tracing_cpu(i) { - data = tr->data[i]; - if (!head_page(data)) - continue; - tracing_reset(data); + tracing_reset(tr, i); } current_trace = type; tr->ctrl = 0; @@ -581,10 +495,7 @@ int register_tracer(struct tracer *type) } /* Only reset on passing, to avoid touching corrupted buffers */ for_each_tracing_cpu(i) { - data = tr->data[i]; - if (!head_page(data)) - continue; - tracing_reset(data); + tracing_reset(tr, i); } printk(KERN_CONT "PASSED\n"); } @@ -630,13 +541,9 @@ void unregister_tracer(struct tracer *type) mutex_unlock(&trace_types_lock); } -void tracing_reset(struct trace_array_cpu *data) +void tracing_reset(struct trace_array *tr, int cpu) { - data->trace_idx = 0; - data->overrun = 0; - data->trace_head = data->trace_tail = head_page(data); - data->trace_head_idx = 0; - data->trace_tail_idx = 0; + ring_buffer_reset_cpu(tr->buffer, cpu); } #define SAVED_CMDLINES 128 @@ -722,70 +629,6 @@ void tracing_record_cmdline(struct task_struct *tsk) trace_save_cmdline(tsk); } -static inline struct list_head * -trace_next_list(struct trace_array_cpu *data, struct list_head *next) -{ - /* - * Roundrobin - but skip the head (which is not a real page): - */ - next = next->next; - if (unlikely(next == &data->trace_pages)) - next = next->next; - BUG_ON(next == &data->trace_pages); - - return next; -} - -static inline void * -trace_next_page(struct trace_array_cpu *data, void *addr) -{ - struct list_head *next; - struct page *page; - - page = virt_to_page(addr); - - next = trace_next_list(data, &page->lru); - page = list_entry(next, struct page, lru); - - return page_address(page); -} - -struct trace_entry * -tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) -{ - unsigned long idx, idx_next; - struct trace_entry *entry; - - data->trace_idx++; - idx = data->trace_head_idx; - idx_next = idx + 1; - - BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); - - entry = data->trace_head + idx * TRACE_ENTRY_SIZE; - - if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { - data->trace_head = trace_next_page(data, data->trace_head); - idx_next = 0; - } - - if (data->trace_head == data->trace_tail && - idx_next == data->trace_tail_idx) { - /* overrun */ - data->overrun++; - data->trace_tail_idx++; - if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { - data->trace_tail = - trace_next_page(data, data->trace_tail); - data->trace_tail_idx = 0; - } - } - - data->trace_head_idx = idx_next; - - return entry; -} - void tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) { @@ -796,7 +639,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) entry->field.preempt_count = pc & 0xff; entry->field.pid = (tsk) ? tsk->pid : 0; - entry->field.t = ftrace_now(raw_smp_processor_id()); entry->field.flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | @@ -808,18 +650,20 @@ void trace_function(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, unsigned long flags) { + struct ring_buffer_event *event; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, flags); entry->type = TRACE_FN; entry->field.fn.ip = ip; entry->field.fn.parent_ip = parent_ip; - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } void @@ -835,13 +679,19 @@ void __trace_stack(struct trace_array *tr, unsigned long flags, int skip) { + struct ring_buffer_event *event; struct trace_entry *entry; struct stack_trace trace; + unsigned long irq_flags; if (!(trace_flags & TRACE_ITER_STACKTRACE)) return; - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, flags); entry->type = TRACE_STACK; @@ -853,28 +703,31 @@ void __trace_stack(struct trace_array *tr, trace.entries = entry->field.stack.caller; save_stack_trace(&trace); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } void __trace_special(void *__tr, void *__data, unsigned long arg1, unsigned long arg2, unsigned long arg3) { + struct ring_buffer_event *event; struct trace_array_cpu *data = __data; struct trace_array *tr = __tr; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, 0); entry->type = TRACE_SPECIAL; entry->field.special.arg1 = arg1; entry->field.special.arg2 = arg2; entry->field.special.arg3 = arg3; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, irq_flags, 4); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); trace_wake_up(); } @@ -886,12 +739,15 @@ tracing_sched_switch_trace(struct trace_array *tr, struct task_struct *next, unsigned long flags) { + struct ring_buffer_event *event; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, flags); entry->type = TRACE_CTX; entry->field.ctx.prev_pid = prev->pid; @@ -901,9 +757,8 @@ tracing_sched_switch_trace(struct trace_array *tr, entry->field.ctx.next_prio = next->prio; entry->field.ctx.next_state = next->state; entry->field.ctx.next_cpu = task_cpu(next); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, flags, 5); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); } void @@ -913,12 +768,15 @@ tracing_sched_wakeup_trace(struct trace_array *tr, struct task_struct *curr, unsigned long flags) { + struct ring_buffer_event *event; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, flags); entry->type = TRACE_WAKE; entry->field.ctx.prev_pid = curr->pid; @@ -928,9 +786,8 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry->field.ctx.next_prio = wakee->prio; entry->field.ctx.next_state = wakee->state; entry->field.ctx.next_cpu = task_cpu(wakee); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, flags, 6); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); trace_wake_up(); } @@ -1011,183 +868,77 @@ enum trace_file_type { TRACE_FILE_LAT_FMT = 1, }; -/* Return the current entry. */ -static struct trace_entry * -trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, - struct trace_iterator *iter, int cpu) -{ - struct page *page; - struct trace_entry *array; - - if (iter->next_idx[cpu] >= tr->entries || - iter->next_idx[cpu] >= data->trace_idx || - (data->trace_head == data->trace_tail && - data->trace_head_idx == data->trace_tail_idx)) - return NULL; - - if (!iter->next_page[cpu]) { - /* Initialize the iterator for this cpu trace buffer */ - WARN_ON(!data->trace_tail); - page = virt_to_page(data->trace_tail); - iter->next_page[cpu] = &page->lru; - iter->next_page_idx[cpu] = data->trace_tail_idx; - } - - page = list_entry(iter->next_page[cpu], struct page, lru); - BUG_ON(&data->trace_pages == &page->lru); - - array = page_address(page); - - WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); - return &array[iter->next_page_idx[cpu]]; -} - -/* Increment the index counter of an iterator by one */ -static void __trace_iterator_increment(struct trace_iterator *iter, int cpu) -{ - iter->next_idx[cpu]++; - iter->next_page_idx[cpu]++; - - if (iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE) { - struct trace_array_cpu *data = iter->tr->data[cpu]; - - iter->next_page_idx[cpu] = 0; - iter->next_page[cpu] = - trace_next_list(data, iter->next_page[cpu]); - } -} - static void trace_iterator_increment(struct trace_iterator *iter, int cpu) { iter->idx++; - __trace_iterator_increment(iter, cpu); + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); } static struct trace_entry * -trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data, - struct trace_iterator *iter, int cpu) +peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) { - struct list_head *next_page; - struct trace_entry *ent; - int idx, next_idx, next_page_idx; - - ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); - - if (likely(!ent || ent->type != TRACE_CONT)) - return ent; - - /* save the iterator details */ - idx = iter->idx; - next_idx = iter->next_idx[cpu]; - next_page_idx = iter->next_page_idx[cpu]; - next_page = iter->next_page[cpu]; - - /* find a real entry */ - do { - __trace_iterator_increment(iter, cpu); - ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); - } while (ent && ent->type != TRACE_CONT); - - /* reset the iterator */ - iter->idx = idx; - iter->next_idx[cpu] = next_idx; - iter->next_page_idx[cpu] = next_page_idx; - iter->next_page[cpu] = next_page; + struct ring_buffer_event *event; + struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; - return ent; + event = ring_buffer_iter_peek(buf_iter, ts); + return event ? ring_buffer_event_data(event) : NULL; } - static struct trace_entry * -__find_next_entry(struct trace_iterator *iter, int *ent_cpu, int inc) +__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { - struct trace_array *tr = iter->tr; + struct ring_buffer *buffer = iter->tr->buffer; struct trace_entry *ent, *next = NULL; + u64 next_ts = 0, ts; int next_cpu = -1; int cpu; for_each_tracing_cpu(cpu) { - if (!head_page(tr->data[cpu])) - continue; - ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + if (ring_buffer_empty_cpu(buffer, cpu)) + continue; - if (ent && ent->type == TRACE_CONT) { - struct trace_array_cpu *data = tr->data[cpu]; - - if (!inc) - ent = trace_entry_next(tr, data, iter, cpu); - else { - while (ent && ent->type == TRACE_CONT) { - __trace_iterator_increment(iter, cpu); - ent = trace_entry_idx(tr, tr->data[cpu], - iter, cpu); - } - } - } + ent = peek_next_entry(iter, cpu, &ts); /* * Pick the entry with the smallest timestamp: */ - if (ent && (!next || ent->field.t < next->field.t)) { + if (ent && (!next || ts < next_ts)) { next = ent; next_cpu = cpu; + next_ts = ts; } } if (ent_cpu) *ent_cpu = next_cpu; + if (ent_ts) + *ent_ts = next_ts; + return next; } /* Find the next real entry, without updating the iterator itself */ static struct trace_entry * -find_next_entry(struct trace_iterator *iter, int *ent_cpu) +find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { - return __find_next_entry(iter, ent_cpu, 0); + return __find_next_entry(iter, ent_cpu, ent_ts); } /* Find the next real entry, and increment the iterator to the next entry */ static void *find_next_entry_inc(struct trace_iterator *iter) { - struct trace_entry *next; - int next_cpu = -1; - - next = __find_next_entry(iter, &next_cpu, 1); - - iter->prev_ent = iter->ent; - iter->prev_cpu = iter->cpu; + iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts); - iter->ent = next; - iter->cpu = next_cpu; - - if (next) + if (iter->ent) trace_iterator_increment(iter, iter->cpu); - return next ? iter : NULL; + return iter->ent ? iter : NULL; } static void trace_consume(struct trace_iterator *iter) { - struct trace_array_cpu *data = iter->tr->data[iter->cpu]; - struct trace_entry *ent; - - again: - data->trace_tail_idx++; - if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { - data->trace_tail = trace_next_page(data, data->trace_tail); - data->trace_tail_idx = 0; - } - - /* Check if we empty it, then reset the index */ - if (data->trace_head == data->trace_tail && - data->trace_head_idx == data->trace_tail_idx) - data->trace_idx = 0; - - ent = trace_entry_idx(iter->tr, iter->tr->data[iter->cpu], - iter, iter->cpu); - if (ent && ent->type == TRACE_CONT) - goto again; + ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); } static void *s_next(struct seq_file *m, void *v, loff_t *pos) @@ -1220,7 +971,7 @@ static void *s_start(struct seq_file *m, loff_t *pos) struct trace_iterator *iter = m->private; void *p = NULL; loff_t l = 0; - int i; + int cpu; mutex_lock(&trace_types_lock); @@ -1239,12 +990,9 @@ static void *s_start(struct seq_file *m, loff_t *pos) iter->ent = NULL; iter->cpu = 0; iter->idx = -1; - iter->prev_ent = NULL; - iter->prev_cpu = -1; - for_each_tracing_cpu(i) { - iter->next_idx[i] = 0; - iter->next_page[i] = NULL; + for_each_tracing_cpu(cpu) { + ring_buffer_iter_reset(iter->buffer_iter[cpu]); } for (p = iter; p && l < *pos; p = s_next(m, p, &l)) @@ -1365,23 +1113,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) struct trace_array *tr = iter->tr; struct trace_array_cpu *data = tr->data[tr->cpu]; struct tracer *type = current_trace; - unsigned long total = 0; - unsigned long entries = 0; - int cpu; + unsigned long total; + unsigned long entries; const char *name = "preemption"; if (type) name = type->name; - for_each_tracing_cpu(cpu) { - if (head_page(tr->data[cpu])) { - total += tr->data[cpu]->trace_idx; - if (tr->data[cpu]->trace_idx > tr->entries) - entries += tr->entries; - else - entries += tr->data[cpu]->trace_idx; - } - } + entries = ring_buffer_entries(iter->tr->buffer); + total = entries + + ring_buffer_overruns(iter->tr->buffer); seq_printf(m, "%s latency trace v1.1.5 on %s\n", name, UTS_RELEASE); @@ -1468,7 +1209,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) unsigned long preempt_mark_thresh = 100; static void -lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, +lat_print_timestamp(struct trace_seq *s, u64 abs_usecs, unsigned long rel_usecs) { trace_seq_printf(s, " %4lldus", abs_usecs); @@ -1488,12 +1229,10 @@ static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; */ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) { - struct trace_array *tr = iter->tr; - struct trace_array_cpu *data = tr->data[iter->cpu]; struct trace_entry *ent; bool ok = true; - ent = trace_entry_idx(tr, data, iter, iter->cpu); + ent = peek_next_entry(iter, iter->cpu, NULL); if (!ent || ent->type != TRACE_CONT) { trace_seq_putc(s, '\n'); return; @@ -1502,8 +1241,8 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) do { if (ok) ok = (trace_seq_printf(s, "%s", ent->cont.buf) > 0); - __trace_iterator_increment(iter, iter->cpu); - ent = trace_entry_idx(tr, data, iter, iter->cpu); + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + ent = peek_next_entry(iter, iter->cpu, NULL); } while (ent && ent->type == TRACE_CONT); if (!ok) @@ -1515,25 +1254,26 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); - struct trace_entry *next_entry = find_next_entry(iter, NULL); + struct trace_entry *next_entry; unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); struct trace_entry *entry = iter->ent; struct trace_field *field = &entry->field; unsigned long abs_usecs; unsigned long rel_usecs; + u64 next_ts; char *comm; int S, T; int i; unsigned state; - if (!next_entry) - next_entry = entry; - if (entry->type == TRACE_CONT) return 1; - rel_usecs = ns2usecs(next_entry->field.t - entry->field.t); - abs_usecs = ns2usecs(entry->field.t - iter->tr->time_start); + next_entry = find_next_entry(iter, NULL, &next_ts); + if (!next_entry) + next_ts = iter->ts; + rel_usecs = ns2usecs(next_ts - iter->ts); + abs_usecs = ns2usecs(iter->ts - iter->tr->time_start); if (verbose) { comm = trace_find_cmdline(field->pid); @@ -1542,7 +1282,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) comm, field->pid, cpu, field->flags, field->preempt_count, trace_idx, - ns2usecs(field->t), + ns2usecs(iter->ts), abs_usecs/1000, abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); @@ -1627,7 +1367,7 @@ static int print_trace_fmt(struct trace_iterator *iter) comm = trace_find_cmdline(iter->ent->field.pid); - t = ns2usecs(field->t); + t = ns2usecs(iter->ts); usec_rem = do_div(t, 1000000ULL); secs = (unsigned long)t; @@ -1732,7 +1472,7 @@ static int print_raw_fmt(struct trace_iterator *iter) field = &entry->field; ret = trace_seq_printf(s, "%d %d %llu ", - field->pid, iter->cpu, field->t); + field->pid, iter->cpu, iter->ts); if (!ret) return 0; @@ -1811,7 +1551,7 @@ static int print_hex_fmt(struct trace_iterator *iter) SEQ_PUT_HEX_FIELD_RET(s, field->pid); SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); - SEQ_PUT_HEX_FIELD_RET(s, field->t); + SEQ_PUT_HEX_FIELD_RET(s, iter->ts); switch (entry->type) { case TRACE_FN: @@ -1861,7 +1601,7 @@ static int print_bin_fmt(struct trace_iterator *iter) SEQ_PUT_FIELD_RET(s, field->pid); SEQ_PUT_FIELD_RET(s, field->cpu); - SEQ_PUT_FIELD_RET(s, field->t); + SEQ_PUT_FIELD_RET(s, iter->ts); switch (entry->type) { case TRACE_FN: @@ -1888,15 +1628,10 @@ static int print_bin_fmt(struct trace_iterator *iter) static int trace_empty(struct trace_iterator *iter) { - struct trace_array_cpu *data; int cpu; for_each_tracing_cpu(cpu) { - data = iter->tr->data[cpu]; - - if (head_page(data) && data->trace_idx && - (data->trace_tail != data->trace_head || - data->trace_tail_idx != data->trace_head_idx)) + if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) return 0; } return 1; @@ -1961,6 +1696,8 @@ static struct trace_iterator * __tracing_open(struct inode *inode, struct file *file, int *ret) { struct trace_iterator *iter; + struct seq_file *m; + int cpu; if (tracing_disabled) { *ret = -ENODEV; @@ -1981,28 +1718,43 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) iter->trace = current_trace; iter->pos = -1; + for_each_tracing_cpu(cpu) { + iter->buffer_iter[cpu] = + ring_buffer_read_start(iter->tr->buffer, cpu); + if (!iter->buffer_iter[cpu]) + goto fail_buffer; + } + /* TODO stop tracer */ *ret = seq_open(file, &tracer_seq_ops); - if (!*ret) { - struct seq_file *m = file->private_data; - m->private = iter; + if (*ret) + goto fail_buffer; - /* stop the trace while dumping */ - if (iter->tr->ctrl) { - tracer_enabled = 0; - ftrace_function_enabled = 0; - } + m = file->private_data; + m->private = iter; - if (iter->trace && iter->trace->open) - iter->trace->open(iter); - } else { - kfree(iter); - iter = NULL; + /* stop the trace while dumping */ + if (iter->tr->ctrl) { + tracer_enabled = 0; + ftrace_function_enabled = 0; } + + if (iter->trace && iter->trace->open) + iter->trace->open(iter); + mutex_unlock(&trace_types_lock); out: return iter; + + fail_buffer: + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + mutex_unlock(&trace_types_lock); + + return ERR_PTR(-ENOMEM); } int tracing_open_generic(struct inode *inode, struct file *filp) @@ -2018,8 +1770,14 @@ int tracing_release(struct inode *inode, struct file *file) { struct seq_file *m = (struct seq_file *)file->private_data; struct trace_iterator *iter = m->private; + int cpu; mutex_lock(&trace_types_lock); + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + if (iter->trace && iter->trace->close) iter->trace->close(iter); @@ -2526,6 +2284,7 @@ static atomic_t tracing_reader; static int tracing_open_pipe(struct inode *inode, struct file *filp) { struct trace_iterator *iter; + int cpu; if (tracing_disabled) return -ENODEV; @@ -2546,17 +2305,38 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) iter->trace = current_trace; filp->private_data = iter; + for_each_tracing_cpu(cpu) { + iter->buffer_iter[cpu] = + ring_buffer_read_start(iter->tr->buffer, cpu); + if (!iter->buffer_iter[cpu]) + goto fail_buffer; + } + if (iter->trace->pipe_open) iter->trace->pipe_open(iter); mutex_unlock(&trace_types_lock); return 0; + + fail_buffer: + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + mutex_unlock(&trace_types_lock); + + return -ENOMEM; } static int tracing_release_pipe(struct inode *inode, struct file *file) { struct trace_iterator *iter = file->private_data; + int cpu; + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } kfree(iter); atomic_dec(&tracing_reader); @@ -2592,13 +2372,10 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; - struct trace_array_cpu *data; - static cpumask_t mask; unsigned long flags; #ifdef CONFIG_FTRACE int ftrace_save; #endif - int cpu; ssize_t sret; /* return any leftover data */ @@ -2687,32 +2464,13 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, * and then release the locks again. */ - cpus_clear(mask); - local_irq_save(flags); + local_irq_disable(); #ifdef CONFIG_FTRACE ftrace_save = ftrace_enabled; ftrace_enabled = 0; #endif smp_wmb(); - for_each_tracing_cpu(cpu) { - data = iter->tr->data[cpu]; - - if (!head_page(data) || !data->trace_idx) - continue; - - atomic_inc(&data->disabled); - cpu_set(cpu, mask); - } - - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - __raw_spin_lock(&data->lock); - - if (data->overrun > iter->last_overrun[cpu]) - iter->overrun[cpu] += - data->overrun - iter->last_overrun[cpu]; - iter->last_overrun[cpu] = data->overrun; - } + ring_buffer_lock(iter->tr->buffer, &flags); while (find_next_entry_inc(iter) != NULL) { int ret; @@ -2731,19 +2489,11 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, break; } - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - __raw_spin_unlock(&data->lock); - } - - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - atomic_dec(&data->disabled); - } + ring_buffer_unlock(iter->tr->buffer, flags); #ifdef CONFIG_FTRACE ftrace_enabled = ftrace_save; #endif - local_irq_restore(flags); + local_irq_enable(); /* Now copy what we have to the user */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); @@ -2776,7 +2526,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, { unsigned long val; char buf[64]; - int i, ret; + int ret; struct trace_array *tr = filp->private_data; if (cnt >= sizeof(buf)) @@ -2804,52 +2554,31 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, goto out; } - if (val > global_trace.entries) { - long pages_requested; - unsigned long freeable_pages; - - /* make sure we have enough memory before mapping */ - pages_requested = - (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE; - - /* account for each buffer (and max_tr) */ - pages_requested *= tracing_nr_buffers * 2; - - /* Check for overflow */ - if (pages_requested < 0) { - cnt = -ENOMEM; - goto out; - } - - freeable_pages = determine_dirtyable_memory(); - - /* we only allow to request 1/4 of useable memory */ - if (pages_requested > - ((freeable_pages + tracing_pages_allocated) / 4)) { - cnt = -ENOMEM; + if (val != global_trace.entries) { + ret = ring_buffer_resize(global_trace.buffer, val); + if (ret < 0) { + cnt = ret; goto out; } - while (global_trace.entries < val) { - if (trace_alloc_page()) { - cnt = -ENOMEM; - goto out; + ret = ring_buffer_resize(max_tr.buffer, val); + if (ret < 0) { + int r; + cnt = ret; + r = ring_buffer_resize(global_trace.buffer, + global_trace.entries); + if (r < 0) { + /* AARGH! We are left with different + * size max buffer!!!! */ + WARN_ON(1); + tracing_disabled = 1; } - /* double check that we don't go over the known pages */ - if (tracing_pages_allocated > pages_requested) - break; + goto out; } - } else { - /* include the number of entries in val (inc of page entries) */ - while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1)) - trace_free_page(); + global_trace.entries = val; } - /* check integrity */ - for_each_tracing_cpu(i) - check_pages(global_trace.data[i]); - filp->f_pos += cnt; /* If check pages failed, return ENOMEM */ @@ -3086,10 +2815,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) static DEFINE_SPINLOCK(trace_buf_lock); static char trace_buf[TRACE_BUF_SIZE]; + struct ring_buffer_event *event; struct trace_array *tr = &global_trace; struct trace_array_cpu *data; struct trace_entry *entry; - unsigned long flags; + unsigned long flags, irq_flags; long disabled; int cpu, len = 0, write, written = 0; @@ -3110,8 +2840,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) len = min(len, TRACE_BUF_SIZE-1); trace_buf[len] = 0; - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out_unlock; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, flags); entry->type = TRACE_PRINT; entry->field.print.ip = ip; @@ -3121,21 +2854,27 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) memcpy(&entry->field.print.buf, trace_buf, write); entry->field.print.buf[write] = 0; written = write; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); if (written != len) entry->field.flags |= TRACE_FLAG_CONT; while (written != len) { - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out_unlock; + entry = ring_buffer_event_data(event); entry->type = TRACE_CONT; write = min(len - written, (int)(TRACE_CONT_BUF_SIZE-1)); memcpy(&entry->cont.buf, trace_buf+written, write); entry->cont.buf[write] = 0; written += write; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } - __raw_spin_unlock(&data->lock); + out_unlock: spin_unlock(&trace_buf_lock); out: @@ -3227,12 +2966,10 @@ void ftrace_dump(void) static DEFINE_SPINLOCK(ftrace_dump_lock); /* use static because iter can be a bit big for the stack */ static struct trace_iterator iter; - struct trace_array_cpu *data; static cpumask_t mask; static int dump_ran; - unsigned long flags; + unsigned long flags, irq_flags; int cnt = 0; - int cpu; /* only one dump */ spin_lock_irqsave(&ftrace_dump_lock, flags); @@ -3258,25 +2995,7 @@ void ftrace_dump(void) cpus_clear(mask); - for_each_tracing_cpu(cpu) { - data = iter.tr->data[cpu]; - - if (!head_page(data) || !data->trace_idx) - continue; - - atomic_inc(&data->disabled); - cpu_set(cpu, mask); - } - - for_each_cpu_mask(cpu, mask) { - data = iter.tr->data[cpu]; - __raw_spin_lock(&data->lock); - - if (data->overrun > iter.last_overrun[cpu]) - iter.overrun[cpu] += - data->overrun - iter.last_overrun[cpu]; - iter.last_overrun[cpu] = data->overrun; - } + ring_buffer_lock(iter.tr->buffer, &irq_flags); while (!trace_empty(&iter)) { @@ -3305,205 +3024,47 @@ void ftrace_dump(void) else printk(KERN_TRACE "---------------------------------\n"); - for_each_cpu_mask(cpu, mask) { - data = iter.tr->data[cpu]; - __raw_spin_unlock(&data->lock); - } - - for_each_cpu_mask(cpu, mask) { - data = iter.tr->data[cpu]; - atomic_dec(&data->disabled); - } - + ring_buffer_unlock(iter.tr->buffer, irq_flags); out: spin_unlock_irqrestore(&ftrace_dump_lock, flags); } -static int trace_alloc_page(void) +__init static int tracer_alloc_buffers(void) { struct trace_array_cpu *data; - struct page *page, *tmp; - LIST_HEAD(pages); - void *array; - unsigned pages_allocated = 0; int i; - /* first allocate a page for each CPU */ - for_each_tracing_cpu(i) { - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_pages; - } - - pages_allocated++; - page = virt_to_page(array); - list_add(&page->lru, &pages); + /* TODO: make the number of buffers hot pluggable with CPUS */ + tracing_buffer_mask = cpu_possible_map; -/* Only allocate if we are actually using the max trace */ -#ifdef CONFIG_TRACER_MAX_TRACE - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_pages; - } - pages_allocated++; - page = virt_to_page(array); - list_add(&page->lru, &pages); -#endif + global_trace.buffer = ring_buffer_alloc(trace_buf_size, + TRACE_BUFFER_FLAGS); + if (!global_trace.buffer) { + printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); + WARN_ON(1); + return 0; } - - /* Now that we successfully allocate a page per CPU, add them */ - for_each_tracing_cpu(i) { - data = global_trace.data[i]; - page = list_entry(pages.next, struct page, lru); - list_del_init(&page->lru); - list_add_tail(&page->lru, &data->trace_pages); - ClearPageLRU(page); + global_trace.entries = ring_buffer_size(global_trace.buffer); #ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - page = list_entry(pages.next, struct page, lru); - list_del_init(&page->lru); - list_add_tail(&page->lru, &data->trace_pages); - SetPageLRU(page); -#endif - } - tracing_pages_allocated += pages_allocated; - global_trace.entries += ENTRIES_PER_PAGE; - - return 0; - - free_pages: - list_for_each_entry_safe(page, tmp, &pages, lru) { - list_del_init(&page->lru); - __free_page(page); + max_tr.buffer = ring_buffer_alloc(trace_buf_size, + TRACE_BUFFER_FLAGS); + if (!max_tr.buffer) { + printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); + WARN_ON(1); + ring_buffer_free(global_trace.buffer); + return 0; } - return -ENOMEM; -} - -static int trace_free_page(void) -{ - struct trace_array_cpu *data; - struct page *page; - struct list_head *p; - int i; - int ret = 0; - - /* free one page from each buffer */ - for_each_tracing_cpu(i) { - data = global_trace.data[i]; - p = data->trace_pages.next; - if (p == &data->trace_pages) { - /* should never happen */ - WARN_ON(1); - tracing_disabled = 1; - ret = -1; - break; - } - page = list_entry(p, struct page, lru); - ClearPageLRU(page); - list_del(&page->lru); - tracing_pages_allocated--; - tracing_pages_allocated--; - __free_page(page); - - tracing_reset(data); - -#ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - p = data->trace_pages.next; - if (p == &data->trace_pages) { - /* should never happen */ - WARN_ON(1); - tracing_disabled = 1; - ret = -1; - break; - } - page = list_entry(p, struct page, lru); - ClearPageLRU(page); - list_del(&page->lru); - __free_page(page); - - tracing_reset(data); + max_tr.entries = ring_buffer_size(max_tr.buffer); + WARN_ON(max_tr.entries != global_trace.entries); #endif - } - global_trace.entries -= ENTRIES_PER_PAGE; - - return ret; -} - -__init static int tracer_alloc_buffers(void) -{ - struct trace_array_cpu *data; - void *array; - struct page *page; - int pages = 0; - int ret = -ENOMEM; - int i; - - /* TODO: make the number of buffers hot pluggable with CPUS */ - tracing_nr_buffers = num_possible_cpus(); - tracing_buffer_mask = cpu_possible_map; /* Allocate the first page for all buffers */ for_each_tracing_cpu(i) { data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); max_tr.data[i] = &per_cpu(max_data, i); - - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_buffers; - } - - /* set the array to the list */ - INIT_LIST_HEAD(&data->trace_pages); - page = virt_to_page(array); - list_add(&page->lru, &data->trace_pages); - /* use the LRU flag to differentiate the two buffers */ - ClearPageLRU(page); - - data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; - max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; - -/* Only allocate if we are actually using the max trace */ -#ifdef CONFIG_TRACER_MAX_TRACE - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_buffers; - } - - INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); - page = virt_to_page(array); - list_add(&page->lru, &max_tr.data[i]->trace_pages); - SetPageLRU(page); -#endif - } - - /* - * Since we allocate by orders of pages, we may be able to - * round up a bit. - */ - global_trace.entries = ENTRIES_PER_PAGE; - pages++; - - while (global_trace.entries < trace_nr_entries) { - if (trace_alloc_page()) - break; - pages++; } - max_tr.entries = global_trace.entries; - - pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n", - pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE); - pr_info(" actual entries %ld\n", global_trace.entries); trace_init_cmdlines(); @@ -3519,38 +3080,13 @@ __init static int tracer_alloc_buffers(void) /* All seems OK, enable tracing */ global_trace.ctrl = tracer_enabled; tracing_disabled = 0; + atomic_notifier_chain_register(&panic_notifier_list, &trace_panic_notifier); register_die_notifier(&trace_die_notifier); return 0; - - free_buffers: - for (i-- ; i >= 0; i--) { - struct page *page, *tmp; - struct trace_array_cpu *data = global_trace.data[i]; - - if (data) { - list_for_each_entry_safe(page, tmp, - &data->trace_pages, lru) { - list_del_init(&page->lru); - __free_page(page); - } - } - -#ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - if (data) { - list_for_each_entry_safe(page, tmp, - &data->trace_pages, lru) { - list_del_init(&page->lru); - __free_page(page); - } - } -#endif - } - return ret; } early_initcall(tracer_alloc_buffers); fs_initcall(tracer_init_debugfs); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b28bf88..f6965f7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -5,6 +5,7 @@ #include #include #include +#include #include #include @@ -102,7 +103,6 @@ struct trace_field { char flags; char preempt_count; int pid; - cycle_t t; union { struct ftrace_entry fn; struct ctx_switch_entry ctx; @@ -139,16 +139,9 @@ struct trace_entry { * the trace, etc.) */ struct trace_array_cpu { - struct list_head trace_pages; atomic_t disabled; - raw_spinlock_t lock; - struct lock_class_key lock_key; /* these fields get copied into max-trace: */ - unsigned trace_head_idx; - unsigned trace_tail_idx; - void *trace_head; /* producer */ - void *trace_tail; /* consumer */ unsigned long trace_idx; unsigned long overrun; unsigned long saved_latency; @@ -172,6 +165,7 @@ struct trace_iterator; * They have on/off state as well: */ struct trace_array { + struct ring_buffer *buffer; unsigned long entries; long ctrl; int cpu; @@ -219,27 +213,21 @@ struct trace_iterator { struct trace_array *tr; struct tracer *trace; void *private; - long last_overrun[NR_CPUS]; - long overrun[NR_CPUS]; + struct ring_buffer_iter *buffer_iter[NR_CPUS]; /* The below is zeroed out in pipe_read */ struct trace_seq seq; struct trace_entry *ent; int cpu; - - struct trace_entry *prev_ent; - int prev_cpu; + u64 ts; unsigned long iter_flags; loff_t pos; - unsigned long next_idx[NR_CPUS]; - struct list_head *next_page[NR_CPUS]; - unsigned next_page_idx[NR_CPUS]; long idx; }; void trace_wake_up(void); -void tracing_reset(struct trace_array_cpu *data); +void tracing_reset(struct trace_array *tr, int cpu); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); void init_tracer_sysprof_debugfs(struct dentry *d_tracer); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index d5c9e2e..3657eec 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -34,7 +34,7 @@ static void boot_trace_init(struct trace_array *tr) trace_boot_enabled = 0; for_each_cpu_mask(cpu, cpu_possible_map) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void boot_trace_ctrl_update(struct trace_array *tr) @@ -74,6 +74,7 @@ struct tracer boot_tracer __read_mostly = void trace_boot(struct boot_trace *it) { + struct ring_buffer_event *event; struct trace_entry *entry; struct trace_array_cpu *data; unsigned long irq_flags; @@ -85,17 +86,18 @@ void trace_boot(struct boot_trace *it) preempt_disable(); data = tr->data[smp_processor_id()]; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, 0); entry->type = TRACE_BOOT; entry->field.initcall = *it; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); trace_wake_up(); + out: preempt_enable(); } diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 3121448..e90eb0c 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -23,7 +23,7 @@ static void function_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void start_function_trace(struct trace_array *tr) diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index ece6cfb..37ad494 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -173,7 +173,7 @@ out_unlock: out: data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); - tracing_reset(data); + tracing_reset(tr, cpu); trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); } @@ -203,7 +203,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); data->critical_start = parent_ip ? : ip; - tracing_reset(data); + tracing_reset(tr, cpu); local_save_flags(flags); @@ -234,7 +234,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) data = tr->data[cpu]; - if (unlikely(!data) || unlikely(!head_page(data)) || + if (unlikely(!data) || !data->critical_start || atomic_read(&data->disabled)) return; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index a108c32..bdbf09d 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -27,7 +27,7 @@ static void mmio_reset_data(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void mmio_trace_init(struct trace_array *tr) @@ -130,10 +130,14 @@ static unsigned long count_overruns(struct trace_iterator *iter) { int cpu; unsigned long cnt = 0; +/* FIXME: */ +#if 0 for_each_online_cpu(cpu) { cnt += iter->overrun[cpu]; iter->overrun[cpu] = 0; } +#endif + (void)cpu; return cnt; } @@ -176,7 +180,7 @@ static int mmio_print_rw(struct trace_iterator *iter) struct trace_entry *entry = iter->ent; struct mmiotrace_rw *rw = &entry->field.mmiorw; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->field.t); + unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; @@ -218,7 +222,7 @@ static int mmio_print_map(struct trace_iterator *iter) struct trace_entry *entry = iter->ent; struct mmiotrace_map *m = &entry->field.mmiomap; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->field.t); + unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; @@ -250,7 +254,7 @@ static int mmio_print_mark(struct trace_iterator *iter) struct trace_entry *entry = iter->ent; const char *msg = entry->field.print.buf; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->field.t); + unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret; @@ -303,19 +307,19 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, struct mmiotrace_rw *rw) { + struct ring_buffer_event *event; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, 0); entry->type = TRACE_MMIO_RW; entry->field.mmiorw = *rw; - - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); } @@ -331,19 +335,19 @@ static void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, struct mmiotrace_map *map) { + struct ring_buffer_event *event; struct trace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); tracing_generic_entry_update(entry, 0); entry->type = TRACE_MMIO_MAP; entry->field.mmiomap = *map; - - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); } diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 16c9ba0..4592b48 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -30,7 +30,7 @@ static void nop_trace_init(struct trace_array *tr) ctx_trace = tr; for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); if (tr->ctrl) start_nop_trace(tr); diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 789e927..e0b06db 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -81,7 +81,7 @@ static void sched_switch_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static int tracing_sched_register(void) diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 08206b4..01e75e0 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -191,7 +191,7 @@ static void __wakeup_reset(struct trace_array *tr) for_each_possible_cpu(cpu) { data = tr->data[cpu]; - tracing_reset(data); + tracing_reset(tr, cpu); } wakeup_cpu = -1; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 5ebd4b1..09cf230 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -18,58 +18,20 @@ static inline int trace_valid_entry(struct trace_entry *entry) return 0; } -static int -trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data) +static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) { - struct trace_entry *entries; - struct page *page; - int idx = 0; - int i; + struct ring_buffer_event *event; + struct trace_entry *entry; - BUG_ON(list_empty(&data->trace_pages)); - page = list_entry(data->trace_pages.next, struct page, lru); - entries = page_address(page); + while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) { + entry = ring_buffer_event_data(event); - check_pages(data); - if (head_page(data) != entries) - goto failed; - - /* - * The starting trace buffer always has valid elements, - * if any element exists. - */ - entries = head_page(data); - - for (i = 0; i < tr->entries; i++) { - - if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) { + if (!trace_valid_entry(entry)) { printk(KERN_CONT ".. invalid entry %d ", - entries[idx].type); + entry->type); goto failed; } - - idx++; - if (idx >= ENTRIES_PER_PAGE) { - page = virt_to_page(entries); - if (page->lru.next == &data->trace_pages) { - if (i != tr->entries - 1) { - printk(KERN_CONT ".. entries buffer mismatch"); - goto failed; - } - } else { - page = list_entry(page->lru.next, struct page, lru); - entries = page_address(page); - } - idx = 0; - } - } - - page = virt_to_page(entries); - if (page->lru.next != &data->trace_pages) { - printk(KERN_CONT ".. too many entries"); - goto failed; } - return 0; failed: @@ -91,13 +53,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) /* Don't allow flipping of max traces now */ raw_local_irq_save(flags); __raw_spin_lock(&ftrace_max_lock); - for_each_possible_cpu(cpu) { - if (!head_page(tr->data[cpu])) - continue; - cnt += tr->data[cpu]->trace_idx; + cnt = ring_buffer_entries(tr->buffer); - ret = trace_test_buffer_cpu(tr, tr->data[cpu]); + for_each_possible_cpu(cpu) { + ret = trace_test_buffer_cpu(tr, cpu); if (ret) break; } diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index db58fb6..9587d3b 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -241,7 +241,7 @@ static void stack_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void start_stack_trace(struct trace_array *tr) -- cgit v1.1 From 777e208d40d0953efc6fb4ab58590da3f7d8f02d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Sep 2008 23:02:42 -0400 Subject: ftrace: take advantage of variable length entries Now that the underlining ring buffer for ftrace now hold variable length entries, we can take advantage of this by only storing the size of the actual event into the buffer. This happens to increase the number of entries in the buffer dramatically. We can also get rid of the "trace_cont" operation, but I'm keeping that until we have no more users. Some of the ftrace tracers can now change their code to adapt to this new feature. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 439 ++++++++++++++++++++++------------------- kernel/trace/trace.h | 81 ++++---- kernel/trace/trace_boot.c | 13 +- kernel/trace/trace_mmiotrace.c | 31 +-- 4 files changed, 301 insertions(+), 263 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ef80793..ed9e47c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -637,9 +637,9 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) pc = preempt_count(); - entry->field.preempt_count = pc & 0xff; - entry->field.pid = (tsk) ? tsk->pid : 0; - entry->field.flags = + entry->preempt_count = pc & 0xff; + entry->pid = (tsk) ? tsk->pid : 0; + entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | @@ -651,7 +651,7 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, unsigned long flags) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct ftrace_entry *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -659,10 +659,10 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_FN; - entry->field.fn.ip = ip; - entry->field.fn.parent_ip = parent_ip; + tracing_generic_entry_update(&entry->ent, flags); + entry->ent.type = TRACE_FN; + entry->ip = ip; + entry->parent_ip = parent_ip; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } @@ -680,7 +680,7 @@ void __trace_stack(struct trace_array *tr, int skip) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct stack_entry *entry; struct stack_trace trace; unsigned long irq_flags; @@ -692,15 +692,15 @@ void __trace_stack(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_STACK; + tracing_generic_entry_update(&entry->ent, flags); + entry->ent.type = TRACE_STACK; - memset(&entry->field.stack, 0, sizeof(entry->field.stack)); + memset(&entry->caller, 0, sizeof(entry->caller)); trace.nr_entries = 0; trace.max_entries = FTRACE_STACK_ENTRIES; trace.skip = skip; - trace.entries = entry->field.stack.caller; + trace.entries = entry->caller; save_stack_trace(&trace); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); @@ -713,7 +713,7 @@ __trace_special(void *__tr, void *__data, struct ring_buffer_event *event; struct trace_array_cpu *data = __data; struct trace_array *tr = __tr; - struct trace_entry *entry; + struct special_entry *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -721,11 +721,11 @@ __trace_special(void *__tr, void *__data, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_SPECIAL; - entry->field.special.arg1 = arg1; - entry->field.special.arg2 = arg2; - entry->field.special.arg3 = arg3; + tracing_generic_entry_update(&entry->ent, 0); + entry->ent.type = TRACE_SPECIAL; + entry->arg1 = arg1; + entry->arg2 = arg2; + entry->arg3 = arg3; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, irq_flags, 4); @@ -740,7 +740,7 @@ tracing_sched_switch_trace(struct trace_array *tr, unsigned long flags) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct ctx_switch_entry *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -748,15 +748,15 @@ tracing_sched_switch_trace(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_CTX; - entry->field.ctx.prev_pid = prev->pid; - entry->field.ctx.prev_prio = prev->prio; - entry->field.ctx.prev_state = prev->state; - entry->field.ctx.next_pid = next->pid; - entry->field.ctx.next_prio = next->prio; - entry->field.ctx.next_state = next->state; - entry->field.ctx.next_cpu = task_cpu(next); + tracing_generic_entry_update(&entry->ent, flags); + entry->ent.type = TRACE_CTX; + entry->prev_pid = prev->pid; + entry->prev_prio = prev->prio; + entry->prev_state = prev->state; + entry->next_pid = next->pid; + entry->next_prio = next->prio; + entry->next_state = next->state; + entry->next_cpu = task_cpu(next); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, flags, 5); } @@ -769,7 +769,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, unsigned long flags) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct ctx_switch_entry *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -777,15 +777,15 @@ tracing_sched_wakeup_trace(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_WAKE; - entry->field.ctx.prev_pid = curr->pid; - entry->field.ctx.prev_prio = curr->prio; - entry->field.ctx.prev_state = curr->state; - entry->field.ctx.next_pid = wakee->pid; - entry->field.ctx.next_prio = wakee->prio; - entry->field.ctx.next_state = wakee->state; - entry->field.ctx.next_cpu = task_cpu(wakee); + tracing_generic_entry_update(&entry->ent, flags); + entry->ent.type = TRACE_WAKE; + entry->prev_pid = curr->pid; + entry->prev_prio = curr->prio; + entry->prev_state = curr->state; + entry->next_pid = wakee->pid; + entry->next_prio = wakee->prio; + entry->next_state = wakee->state; + entry->next_cpu = task_cpu(wakee); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); __trace_stack(tr, data, flags, 6); @@ -1173,20 +1173,19 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) static void lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { - struct trace_field *field = &entry->field; int hardirq, softirq; char *comm; - comm = trace_find_cmdline(field->pid); + comm = trace_find_cmdline(entry->pid); - trace_seq_printf(s, "%8.8s-%-5d ", comm, field->pid); + trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); trace_seq_printf(s, "%3d", cpu); trace_seq_printf(s, "%c%c", - (field->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', - ((field->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); + (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', + ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); - hardirq = field->flags & TRACE_FLAG_HARDIRQ; - softirq = field->flags & TRACE_FLAG_SOFTIRQ; + hardirq = entry->flags & TRACE_FLAG_HARDIRQ; + softirq = entry->flags & TRACE_FLAG_SOFTIRQ; if (hardirq && softirq) { trace_seq_putc(s, 'H'); } else { @@ -1200,8 +1199,8 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) } } - if (field->preempt_count) - trace_seq_printf(s, "%x", field->preempt_count); + if (entry->preempt_count) + trace_seq_printf(s, "%x", entry->preempt_count); else trace_seq_puts(s, "."); } @@ -1230,6 +1229,7 @@ static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) { struct trace_entry *ent; + struct trace_field_cont *cont; bool ok = true; ent = peek_next_entry(iter, iter->cpu, NULL); @@ -1239,8 +1239,9 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) } do { + cont = (struct trace_field_cont *)ent; if (ok) - ok = (trace_seq_printf(s, "%s", ent->cont.buf) > 0); + ok = (trace_seq_printf(s, "%s", cont->buf) > 0); ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); ent = peek_next_entry(iter, iter->cpu, NULL); } while (ent && ent->type == TRACE_CONT); @@ -1257,7 +1258,6 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) struct trace_entry *next_entry; unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); struct trace_entry *entry = iter->ent; - struct trace_field *field = &entry->field; unsigned long abs_usecs; unsigned long rel_usecs; u64 next_ts; @@ -1276,12 +1276,12 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) abs_usecs = ns2usecs(iter->ts - iter->tr->time_start); if (verbose) { - comm = trace_find_cmdline(field->pid); + comm = trace_find_cmdline(entry->pid); trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]" " %ld.%03ldms (+%ld.%03ldms): ", comm, - field->pid, cpu, field->flags, - field->preempt_count, trace_idx, + entry->pid, cpu, entry->flags, + entry->preempt_count, trace_idx, ns2usecs(iter->ts), abs_usecs/1000, abs_usecs % 1000, rel_usecs/1000, @@ -1291,53 +1291,69 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) lat_print_timestamp(s, abs_usecs, rel_usecs); } switch (entry->type) { - case TRACE_FN: - seq_print_ip_sym(s, field->fn.ip, sym_flags); + case TRACE_FN: { + struct ftrace_entry *field = (struct ftrace_entry *)entry; + + seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_puts(s, " ("); - if (kretprobed(field->fn.parent_ip)) + if (kretprobed(field->parent_ip)) trace_seq_puts(s, KRETPROBE_MSG); else - seq_print_ip_sym(s, field->fn.parent_ip, sym_flags); + seq_print_ip_sym(s, field->parent_ip, sym_flags); trace_seq_puts(s, ")\n"); break; + } case TRACE_CTX: - case TRACE_WAKE: - T = field->ctx.next_state < sizeof(state_to_char) ? - state_to_char[field->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field = + (struct ctx_switch_entry *)entry; + + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; - state = field->ctx.prev_state ? - __ffs(field->ctx.prev_state) + 1 : 0; + state = field->prev_state ? + __ffs(field->prev_state) + 1 : 0; S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X'; - comm = trace_find_cmdline(field->ctx.next_pid); + comm = trace_find_cmdline(field->next_pid); trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n", - field->ctx.prev_pid, - field->ctx.prev_prio, + field->prev_pid, + field->prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - field->ctx.next_cpu, - field->ctx.next_pid, - field->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T, comm); break; - case TRACE_SPECIAL: + } + case TRACE_SPECIAL: { + struct special_entry *field = (struct special_entry *)entry; + trace_seq_printf(s, "# %ld %ld %ld\n", - field->special.arg1, - field->special.arg2, - field->special.arg3); + field->arg1, + field->arg2, + field->arg3); break; - case TRACE_STACK: + } + case TRACE_STACK: { + struct stack_entry *field = (struct stack_entry *)entry; + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) trace_seq_puts(s, " <= "); - seq_print_ip_sym(s, field->stack.caller[i], sym_flags); + seq_print_ip_sym(s, field->caller[i], sym_flags); } trace_seq_puts(s, "\n"); break; - case TRACE_PRINT: - seq_print_ip_sym(s, field->print.ip, sym_flags); - trace_seq_printf(s, ": %s", field->print.buf); - if (field->flags & TRACE_FLAG_CONT) + } + case TRACE_PRINT: { + struct print_entry *field = (struct print_entry *)entry; + + seq_print_ip_sym(s, field->ip, sym_flags); + trace_seq_printf(s, ": %s", field->buf); + if (entry->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; + } default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } @@ -1349,7 +1365,6 @@ static int print_trace_fmt(struct trace_iterator *iter) struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); struct trace_entry *entry; - struct trace_field *field; unsigned long usec_rem; unsigned long long t; unsigned long secs; @@ -1363,15 +1378,13 @@ static int print_trace_fmt(struct trace_iterator *iter) if (entry->type == TRACE_CONT) return 1; - field = &entry->field; - - comm = trace_find_cmdline(iter->ent->field.pid); + comm = trace_find_cmdline(iter->ent->pid); t = ns2usecs(iter->ts); usec_rem = do_div(t, 1000000ULL); secs = (unsigned long)t; - ret = trace_seq_printf(s, "%16s-%-5d ", comm, field->pid); + ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); if (!ret) return 0; ret = trace_seq_printf(s, "[%03d] ", iter->cpu); @@ -1382,20 +1395,22 @@ static int print_trace_fmt(struct trace_iterator *iter) return 0; switch (entry->type) { - case TRACE_FN: - ret = seq_print_ip_sym(s, field->fn.ip, sym_flags); + case TRACE_FN: { + struct ftrace_entry *field = (struct ftrace_entry *)entry; + + ret = seq_print_ip_sym(s, field->ip, sym_flags); if (!ret) return 0; if ((sym_flags & TRACE_ITER_PRINT_PARENT) && - field->fn.parent_ip) { + field->parent_ip) { ret = trace_seq_printf(s, " <-"); if (!ret) return 0; - if (kretprobed(field->fn.parent_ip)) + if (kretprobed(field->parent_ip)) ret = trace_seq_puts(s, KRETPROBE_MSG); else ret = seq_print_ip_sym(s, - field->fn.parent_ip, + field->parent_ip, sym_flags); if (!ret) return 0; @@ -1404,40 +1419,50 @@ static int print_trace_fmt(struct trace_iterator *iter) if (!ret) return 0; break; + } case TRACE_CTX: - case TRACE_WAKE: - S = field->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[field->ctx.prev_state] : 'X'; - T = field->ctx.next_state < sizeof(state_to_char) ? - state_to_char[field->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field = + (struct ctx_switch_entry *)entry; + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n", - field->ctx.prev_pid, - field->ctx.prev_prio, + field->prev_pid, + field->prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - field->ctx.next_cpu, - field->ctx.next_pid, - field->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T); if (!ret) return 0; break; - case TRACE_SPECIAL: + } + case TRACE_SPECIAL: { + struct special_entry *field = (struct special_entry *)entry; + ret = trace_seq_printf(s, "# %ld %ld %ld\n", - field->special.arg1, - field->special.arg2, - field->special.arg3); + field->arg1, + field->arg2, + field->arg3); if (!ret) return 0; break; - case TRACE_STACK: + } + case TRACE_STACK: { + struct stack_entry *field = (struct stack_entry *)entry; + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) { ret = trace_seq_puts(s, " <= "); if (!ret) return 0; } - ret = seq_print_ip_sym(s, field->stack.caller[i], + ret = seq_print_ip_sym(s, field->caller[i], sym_flags); if (!ret) return 0; @@ -1446,13 +1471,17 @@ static int print_trace_fmt(struct trace_iterator *iter) if (!ret) return 0; break; - case TRACE_PRINT: - seq_print_ip_sym(s, field->print.ip, sym_flags); - trace_seq_printf(s, ": %s", field->print.buf); - if (field->flags & TRACE_FLAG_CONT) + } + case TRACE_PRINT: { + struct print_entry *field = (struct print_entry *)entry; + + seq_print_ip_sym(s, field->ip, sym_flags); + trace_seq_printf(s, ": %s", field->buf); + if (entry->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; } + } return 1; } @@ -1460,7 +1489,6 @@ static int print_raw_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; - struct trace_field *field; int ret; int S, T; @@ -1469,56 +1497,66 @@ static int print_raw_fmt(struct trace_iterator *iter) if (entry->type == TRACE_CONT) return 1; - field = &entry->field; - ret = trace_seq_printf(s, "%d %d %llu ", - field->pid, iter->cpu, iter->ts); + entry->pid, iter->cpu, iter->ts); if (!ret) return 0; switch (entry->type) { - case TRACE_FN: + case TRACE_FN: { + struct ftrace_entry *field = (struct ftrace_entry *)entry; + ret = trace_seq_printf(s, "%x %x\n", - field->fn.ip, - field->fn.parent_ip); + field->ip, + field->parent_ip); if (!ret) return 0; break; + } case TRACE_CTX: - case TRACE_WAKE: - S = field->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[field->ctx.prev_state] : 'X'; - T = field->ctx.next_state < sizeof(state_to_char) ? - state_to_char[field->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field = + (struct ctx_switch_entry *)entry; + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n", - field->ctx.prev_pid, - field->ctx.prev_prio, + field->prev_pid, + field->prev_prio, S, - field->ctx.next_cpu, - field->ctx.next_pid, - field->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T); if (!ret) return 0; break; + } case TRACE_SPECIAL: - case TRACE_STACK: + case TRACE_STACK: { + struct special_entry *field = (struct special_entry *)entry; + ret = trace_seq_printf(s, "# %ld %ld %ld\n", - field->special.arg1, - field->special.arg2, - field->special.arg3); + field->arg1, + field->arg2, + field->arg3); if (!ret) return 0; break; - case TRACE_PRINT: - trace_seq_printf(s, "# %lx %s", - field->print.ip, field->print.buf); - if (field->flags & TRACE_FLAG_CONT) + } + case TRACE_PRINT: { + struct print_entry *field = (struct print_entry *)entry; + + trace_seq_printf(s, "# %lx %s", field->ip, field->buf); + if (entry->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); break; } + } return 1; } @@ -1539,7 +1577,6 @@ static int print_hex_fmt(struct trace_iterator *iter) struct trace_seq *s = &iter->seq; unsigned char newline = '\n'; struct trace_entry *entry; - struct trace_field *field; int S, T; entry = iter->ent; @@ -1547,40 +1584,48 @@ static int print_hex_fmt(struct trace_iterator *iter) if (entry->type == TRACE_CONT) return 1; - field = &entry->field; - - SEQ_PUT_HEX_FIELD_RET(s, field->pid); + SEQ_PUT_HEX_FIELD_RET(s, entry->pid); SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); SEQ_PUT_HEX_FIELD_RET(s, iter->ts); switch (entry->type) { - case TRACE_FN: - SEQ_PUT_HEX_FIELD_RET(s, field->fn.ip); - SEQ_PUT_HEX_FIELD_RET(s, field->fn.parent_ip); + case TRACE_FN: { + struct ftrace_entry *field = (struct ftrace_entry *)entry; + + SEQ_PUT_HEX_FIELD_RET(s, field->ip); + SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip); break; + } case TRACE_CTX: - case TRACE_WAKE: - S = field->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[field->ctx.prev_state] : 'X'; - T = field->ctx.next_state < sizeof(state_to_char) ? - state_to_char[field->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field = + (struct ctx_switch_entry *)entry; + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; - SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_pid); - SEQ_PUT_HEX_FIELD_RET(s, field->ctx.prev_prio); + SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio); SEQ_PUT_HEX_FIELD_RET(s, S); - SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_cpu); - SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_pid); - SEQ_PUT_HEX_FIELD_RET(s, field->ctx.next_prio); + SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu); + SEQ_PUT_HEX_FIELD_RET(s, field->next_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->next_prio); SEQ_PUT_HEX_FIELD_RET(s, T); break; + } case TRACE_SPECIAL: - case TRACE_STACK: - SEQ_PUT_HEX_FIELD_RET(s, field->special.arg1); - SEQ_PUT_HEX_FIELD_RET(s, field->special.arg2); - SEQ_PUT_HEX_FIELD_RET(s, field->special.arg3); + case TRACE_STACK: { + struct special_entry *field = (struct special_entry *)entry; + + SEQ_PUT_HEX_FIELD_RET(s, field->arg1); + SEQ_PUT_HEX_FIELD_RET(s, field->arg2); + SEQ_PUT_HEX_FIELD_RET(s, field->arg3); break; } + } SEQ_PUT_FIELD_RET(s, newline); return 1; @@ -1590,39 +1635,46 @@ static int print_bin_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; - struct trace_field *field; entry = iter->ent; if (entry->type == TRACE_CONT) return 1; - field = &entry->field; - - SEQ_PUT_FIELD_RET(s, field->pid); - SEQ_PUT_FIELD_RET(s, field->cpu); + SEQ_PUT_FIELD_RET(s, entry->pid); + SEQ_PUT_FIELD_RET(s, iter->cpu); SEQ_PUT_FIELD_RET(s, iter->ts); switch (entry->type) { - case TRACE_FN: - SEQ_PUT_FIELD_RET(s, field->fn.ip); - SEQ_PUT_FIELD_RET(s, field->fn.parent_ip); + case TRACE_FN: { + struct ftrace_entry *field = (struct ftrace_entry *)entry; + + SEQ_PUT_FIELD_RET(s, field->ip); + SEQ_PUT_FIELD_RET(s, field->parent_ip); break; - case TRACE_CTX: - SEQ_PUT_FIELD_RET(s, field->ctx.prev_pid); - SEQ_PUT_FIELD_RET(s, field->ctx.prev_prio); - SEQ_PUT_FIELD_RET(s, field->ctx.prev_state); - SEQ_PUT_FIELD_RET(s, field->ctx.next_pid); - SEQ_PUT_FIELD_RET(s, field->ctx.next_prio); - SEQ_PUT_FIELD_RET(s, field->ctx.next_state); + } + case TRACE_CTX: { + struct ctx_switch_entry *field = + (struct ctx_switch_entry *)entry; + + SEQ_PUT_FIELD_RET(s, field->prev_pid); + SEQ_PUT_FIELD_RET(s, field->prev_prio); + SEQ_PUT_FIELD_RET(s, field->prev_state); + SEQ_PUT_FIELD_RET(s, field->next_pid); + SEQ_PUT_FIELD_RET(s, field->next_prio); + SEQ_PUT_FIELD_RET(s, field->next_state); break; + } case TRACE_SPECIAL: - case TRACE_STACK: - SEQ_PUT_FIELD_RET(s, field->special.arg1); - SEQ_PUT_FIELD_RET(s, field->special.arg2); - SEQ_PUT_FIELD_RET(s, field->special.arg3); + case TRACE_STACK: { + struct special_entry *field = (struct special_entry *)entry; + + SEQ_PUT_FIELD_RET(s, field->arg1); + SEQ_PUT_FIELD_RET(s, field->arg2); + SEQ_PUT_FIELD_RET(s, field->arg3); break; } + } return 1; } @@ -2818,10 +2870,10 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) struct ring_buffer_event *event; struct trace_array *tr = &global_trace; struct trace_array_cpu *data; - struct trace_entry *entry; + struct print_entry *entry; unsigned long flags, irq_flags; long disabled; - int cpu, len = 0, write, written = 0; + int cpu, len = 0, size; if (!tr->ctrl || tracing_disabled) return 0; @@ -2840,40 +2892,19 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) len = min(len, TRACE_BUF_SIZE-1); trace_buf[len] = 0; - event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), - &irq_flags); + size = sizeof(*entry) + len + 1; + event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags); if (!event) goto out_unlock; - entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_PRINT; - entry->field.print.ip = ip; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags); + entry->ent.type = TRACE_PRINT; + entry->ip = ip; - write = min(len, (int)(TRACE_PRINT_BUF_SIZE-1)); - - memcpy(&entry->field.print.buf, trace_buf, write); - entry->field.print.buf[write] = 0; - written = write; + memcpy(&entry->buf, trace_buf, len); + entry->buf[len] = 0; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - if (written != len) - entry->field.flags |= TRACE_FLAG_CONT; - - while (written != len) { - event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), - &irq_flags); - if (!event) - goto out_unlock; - entry = ring_buffer_event_data(event); - - entry->type = TRACE_CONT; - write = min(len - written, (int)(TRACE_CONT_BUF_SIZE-1)); - memcpy(&entry->cont.buf, trace_buf+written, write); - entry->cont.buf[write] = 0; - written += write; - ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - } - out_unlock: spin_unlock(&trace_buf_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f6965f7..e541a6b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -27,9 +27,24 @@ enum trace_type { }; /* + * The trace entry - the most basic unit of tracing. This is what + * is printed in the end as a single line in the trace output, such as: + * + * bash-15816 [01] 235.197585: idle_cpu <- irq_enter + */ +struct trace_entry { + unsigned char type; + unsigned char cpu; + unsigned char flags; + unsigned char preempt_count; + int pid; +}; + +/* * Function trace entry - function address and parent function addres: */ struct ftrace_entry { + struct trace_entry ent; unsigned long ip; unsigned long parent_ip; }; @@ -39,6 +54,7 @@ extern struct tracer boot_tracer; * Context switch trace entry - which task (and prio) we switched from/to: */ struct ctx_switch_entry { + struct trace_entry ent; unsigned int prev_pid; unsigned char prev_prio; unsigned char prev_state; @@ -52,6 +68,7 @@ struct ctx_switch_entry { * Special (free-form) trace entry: */ struct special_entry { + struct trace_entry ent; unsigned long arg1; unsigned long arg2; unsigned long arg3; @@ -64,6 +81,7 @@ struct special_entry { #define FTRACE_STACK_ENTRIES 8 struct stack_entry { + struct trace_entry ent; unsigned long caller[FTRACE_STACK_ENTRIES]; }; @@ -71,10 +89,34 @@ struct stack_entry { * ftrace_printk entry: */ struct print_entry { + struct trace_entry ent; unsigned long ip; char buf[]; }; +#define TRACE_OLD_SIZE 88 + +struct trace_field_cont { + unsigned char type; + /* Temporary till we get rid of this completely */ + char buf[TRACE_OLD_SIZE - 1]; +}; + +struct trace_mmiotrace_rw { + struct trace_entry ent; + struct mmiotrace_rw rw; +}; + +struct trace_mmiotrace_map { + struct trace_entry ent; + struct mmiotrace_map map; +}; + +struct trace_boot { + struct trace_entry ent; + struct boot_trace initcall; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -92,46 +134,7 @@ enum trace_flag_type { TRACE_FLAG_CONT = 0x10, }; -/* - * The trace field - the most basic unit of tracing. This is what - * is printed in the end as a single line in the trace output, such as: - * - * bash-15816 [01] 235.197585: idle_cpu <- irq_enter - */ -struct trace_field { - char cpu; - char flags; - char preempt_count; - int pid; - union { - struct ftrace_entry fn; - struct ctx_switch_entry ctx; - struct special_entry special; - struct stack_entry stack; - struct print_entry print; - struct mmiotrace_rw mmiorw; - struct mmiotrace_map mmiomap; - struct boot_trace initcall; - }; -}; - -struct trace_field_cont { - char buf[sizeof(struct trace_field)]; -}; - -struct trace_entry { - char type; - union { - struct trace_field field; - struct trace_field_cont cont; - }; -}; - -#define TRACE_ENTRY_SIZE sizeof(struct trace_entry) #define TRACE_BUF_SIZE 1024 -#define TRACE_PRINT_BUF_SIZE \ - (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) -#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) /* * The CPU trace array - it consists of thousands of trace entries diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 3657eec..fa8cca1 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -49,10 +49,11 @@ static int initcall_print_line(struct trace_iterator *iter) { int ret = 0; struct trace_entry *entry = iter->ent; - struct boot_trace *it = &entry->field.initcall; + struct trace_boot *field = (struct trace_boot *)entry; + struct boot_trace *it = &field->initcall; struct trace_seq *s = &iter->seq; - if (iter->ent->type == TRACE_BOOT) + if (entry->type == TRACE_BOOT) ret = trace_seq_printf(s, "%pF called from %i " "returned %d after %lld msecs\n", it->func, it->caller, it->result, @@ -75,7 +76,7 @@ struct tracer boot_tracer __read_mostly = void trace_boot(struct boot_trace *it) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct trace_boot *entry; struct trace_array_cpu *data; unsigned long irq_flags; struct trace_array *tr = boot_trace; @@ -91,9 +92,9 @@ void trace_boot(struct boot_trace *it) if (!event) goto out; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_BOOT; - entry->field.initcall = *it; + tracing_generic_entry_update(&entry->ent, 0); + entry->ent.type = TRACE_BOOT; + entry->initcall = *it; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index bdbf09d..3df441e 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -178,14 +178,16 @@ print_out: static int mmio_print_rw(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_rw *rw = &entry->field.mmiorw; + struct trace_mmiotrace_rw *field = + (struct trace_mmiotrace_rw *)entry; + struct mmiotrace_rw *rw = &field->rw; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; - switch (entry->field.mmiorw.opcode) { + switch (rw->opcode) { case MMIO_READ: ret = trace_seq_printf(s, "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", @@ -220,14 +222,14 @@ static int mmio_print_rw(struct trace_iterator *iter) static int mmio_print_map(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_map *m = &entry->field.mmiomap; + struct mmiotrace_map *m = (struct mmiotrace_map *)entry; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; - switch (entry->field.mmiorw.opcode) { + switch (m->opcode) { case MMIO_PROBE: ret = trace_seq_printf(s, "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", @@ -252,7 +254,8 @@ static int mmio_print_map(struct trace_iterator *iter) static int mmio_print_mark(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - const char *msg = entry->field.print.buf; + struct print_entry *print = (struct print_entry *)entry; + const char *msg = print->buf; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); @@ -264,7 +267,7 @@ static int mmio_print_mark(struct trace_iterator *iter) if (!ret) return 0; - if (entry->field.flags & TRACE_FLAG_CONT) + if (entry->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); return 1; @@ -308,7 +311,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, struct mmiotrace_rw *rw) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct trace_mmiotrace_rw *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -316,9 +319,9 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_RW; - entry->field.mmiorw = *rw; + tracing_generic_entry_update(&entry->ent, 0); + entry->ent.type = TRACE_MMIO_RW; + entry->rw = *rw; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); @@ -336,7 +339,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr, struct mmiotrace_map *map) { struct ring_buffer_event *event; - struct trace_entry *entry; + struct trace_mmiotrace_map *entry; unsigned long irq_flags; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), @@ -344,9 +347,9 @@ static void __trace_mmiotrace_map(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_MAP; - entry->field.mmiomap = *map; + tracing_generic_entry_update(&entry->ent, 0); + entry->ent.type = TRACE_MMIO_MAP; + entry->map = *map; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); -- cgit v1.1 From 2c4f035f6c3e8fda661eb6105aa51ef07aa71607 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 29 Sep 2008 20:18:34 +0200 Subject: tracing/ftrace: change the type of the print_line callback We need a kind of disambiguation when a print_line callback returns 0. _There is not enough space to print all the entry. Please flush the seq and retry. _I can't handle this type of entry This patch changes the type of this callback for better information. Also some changes have been made in this V2. _ Only relay to default functions after the print_line callback fails. _ This patch doesn't fix the issue with the broken pipe (see patch 2/4 for that) Some things are still in discussion: _ Find better names for the enum print_line_t values _ Change the type of print_trace_line into boolean. Patches to change that can be sent later. Signed-off-by: Frederic Weisbecker Acked-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 77 ++++++++++++++++++++++++++++------------------------ kernel/trace/trace.h | 10 ++++++- 2 files changed, 50 insertions(+), 37 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ed9e47c..b38a4bb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1250,7 +1250,7 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) trace_seq_putc(s, '\n'); } -static int +static enum print_line_t print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { struct trace_seq *s = &iter->seq; @@ -1267,7 +1267,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) unsigned state; if (entry->type == TRACE_CONT) - return 1; + return TRACE_TYPE_HANDLED; next_entry = find_next_entry(iter, NULL, &next_ts); if (!next_entry) @@ -1357,10 +1357,10 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } - return 1; + return TRACE_TYPE_HANDLED; } -static int print_trace_fmt(struct trace_iterator *iter) +static enum print_line_t print_trace_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); @@ -1376,7 +1376,7 @@ static int print_trace_fmt(struct trace_iterator *iter) entry = iter->ent; if (entry->type == TRACE_CONT) - return 1; + return TRACE_TYPE_HANDLED; comm = trace_find_cmdline(iter->ent->pid); @@ -1386,13 +1386,13 @@ static int print_trace_fmt(struct trace_iterator *iter) ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; ret = trace_seq_printf(s, "[%03d] ", iter->cpu); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; switch (entry->type) { case TRACE_FN: { @@ -1400,12 +1400,12 @@ static int print_trace_fmt(struct trace_iterator *iter) ret = seq_print_ip_sym(s, field->ip, sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; if ((sym_flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) { ret = trace_seq_printf(s, " <-"); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; if (kretprobed(field->parent_ip)) ret = trace_seq_puts(s, KRETPROBE_MSG); else @@ -1413,11 +1413,11 @@ static int print_trace_fmt(struct trace_iterator *iter) field->parent_ip, sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } ret = trace_seq_printf(s, "\n"); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_CTX: @@ -1439,7 +1439,7 @@ static int print_trace_fmt(struct trace_iterator *iter) field->next_prio, T); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_SPECIAL: { @@ -1450,7 +1450,7 @@ static int print_trace_fmt(struct trace_iterator *iter) field->arg2, field->arg3); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_STACK: { @@ -1460,16 +1460,16 @@ static int print_trace_fmt(struct trace_iterator *iter) if (i) { ret = trace_seq_puts(s, " <= "); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } ret = seq_print_ip_sym(s, field->caller[i], sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } ret = trace_seq_puts(s, "\n"); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_PRINT: { @@ -1482,10 +1482,10 @@ static int print_trace_fmt(struct trace_iterator *iter) break; } } - return 1; + return TRACE_TYPE_HANDLED; } -static int print_raw_fmt(struct trace_iterator *iter) +static enum print_line_t print_raw_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; @@ -1495,12 +1495,12 @@ static int print_raw_fmt(struct trace_iterator *iter) entry = iter->ent; if (entry->type == TRACE_CONT) - return 1; + return TRACE_TYPE_HANDLED; ret = trace_seq_printf(s, "%d %d %llu ", entry->pid, iter->cpu, iter->ts); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; switch (entry->type) { case TRACE_FN: { @@ -1510,7 +1510,7 @@ static int print_raw_fmt(struct trace_iterator *iter) field->ip, field->parent_ip); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_CTX: @@ -1533,7 +1533,7 @@ static int print_raw_fmt(struct trace_iterator *iter) field->next_prio, T); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_SPECIAL: @@ -1545,7 +1545,7 @@ static int print_raw_fmt(struct trace_iterator *iter) field->arg2, field->arg3); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } case TRACE_PRINT: { @@ -1557,7 +1557,7 @@ static int print_raw_fmt(struct trace_iterator *iter) break; } } - return 1; + return TRACE_TYPE_HANDLED; } #define SEQ_PUT_FIELD_RET(s, x) \ @@ -1572,7 +1572,7 @@ do { \ return 0; \ } while (0) -static int print_hex_fmt(struct trace_iterator *iter) +static enum print_line_t print_hex_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; unsigned char newline = '\n'; @@ -1582,7 +1582,7 @@ static int print_hex_fmt(struct trace_iterator *iter) entry = iter->ent; if (entry->type == TRACE_CONT) - return 1; + return TRACE_TYPE_HANDLED; SEQ_PUT_HEX_FIELD_RET(s, entry->pid); SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); @@ -1628,10 +1628,10 @@ static int print_hex_fmt(struct trace_iterator *iter) } SEQ_PUT_FIELD_RET(s, newline); - return 1; + return TRACE_TYPE_HANDLED; } -static int print_bin_fmt(struct trace_iterator *iter) +static enum print_line_t print_bin_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; @@ -1639,7 +1639,7 @@ static int print_bin_fmt(struct trace_iterator *iter) entry = iter->ent; if (entry->type == TRACE_CONT) - return 1; + return TRACE_TYPE_HANDLED; SEQ_PUT_FIELD_RET(s, entry->pid); SEQ_PUT_FIELD_RET(s, iter->cpu); @@ -1686,13 +1686,18 @@ static int trace_empty(struct trace_iterator *iter) if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) return 0; } - return 1; + return TRACE_TYPE_HANDLED; } -static int print_trace_line(struct trace_iterator *iter) +static enum print_line_t print_trace_line(struct trace_iterator *iter) { - if (iter->trace && iter->trace->print_line) - return iter->trace->print_line(iter); + enum print_line_t ret; + + if (iter->trace && iter->trace->print_line) { + ret = iter->trace->print_line(iter); + if (ret != TRACE_TYPE_UNHANDLED) + return ret; + } if (trace_flags & TRACE_ITER_BIN) return print_bin_fmt(iter); @@ -2525,11 +2530,11 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, ring_buffer_lock(iter->tr->buffer, &flags); while (find_next_entry_inc(iter) != NULL) { - int ret; + enum print_line_t ret; int len = iter->seq.len; ret = print_trace_line(iter); - if (!ret) { + if (ret == TRACE_TYPE_PARTIAL_LINE) { /* don't print partial lines */ iter->seq.len = len; break; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index e541a6b..a921ba5 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -177,6 +177,14 @@ struct trace_array { struct trace_array_cpu *data[NR_CPUS]; }; + +/* Return values for print_line callback */ +enum print_line_t { + TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ + TRACE_TYPE_HANDLED = 1, + TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ +}; + /* * A specific tracer, represented by methods that operate on a trace array: */ @@ -197,7 +205,7 @@ struct tracer { int (*selftest)(struct tracer *trace, struct trace_array *tr); #endif - int (*print_line)(struct trace_iterator *iter); + enum print_line_t (*print_line)(struct trace_iterator *iter); struct tracer *next; int print_max; }; -- cgit v1.1 From 9ff4b9744c187cae58c3774361ea090addbc4130 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 29 Sep 2008 20:23:48 +0200 Subject: tracing/ftrace: fix pipe breaking This patch fixes a bug which break the pipe when the seq is empty. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b38a4bb..6a1c76b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2439,7 +2439,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, sret = trace_seq_to_user(&iter->seq, ubuf, cnt); if (sret != -EBUSY) return sret; - sret = 0; trace_seq_reset(&iter->seq); @@ -2450,6 +2449,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, goto out; } +waitagain: + sret = 0; while (trace_empty(iter)) { if ((filp->f_flags & O_NONBLOCK)) { @@ -2556,8 +2557,13 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, sret = trace_seq_to_user(&iter->seq, ubuf, cnt); if (iter->seq.readpos >= iter->seq.len) trace_seq_reset(&iter->seq); + + /* + * If there was nothing to send to user, inspite of consuming trace + * entries, go back to wait for more entries. + */ if (sret == -EBUSY) - sret = 0; + goto waitagain; out: mutex_unlock(&trace_types_lock); -- cgit v1.1 From 07f4e4f790895d55f46aaf89e7437da4a585989c Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 29 Sep 2008 20:27:42 +0200 Subject: tracing/ftrace: adapt mmiotrace to the new type of print_line Adapt mmiotrace to the new print_line type. By default, it ignores (and consumes) types it doesn't support. Signed-off-by: Frederic Weisbecker Acked-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- kernel/trace/trace_mmiotrace.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 3df441e..1a266aa 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -175,7 +175,7 @@ print_out: return (ret == -EBUSY) ? 0 : ret; } -static int mmio_print_rw(struct trace_iterator *iter) +static enum print_line_t mmio_print_rw(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct trace_mmiotrace_rw *field = @@ -215,11 +215,11 @@ static int mmio_print_rw(struct trace_iterator *iter) break; } if (ret) - return 1; - return 0; + return TRACE_TYPE_HANDLED; + return TRACE_TYPE_PARTIAL_LINE; } -static int mmio_print_map(struct trace_iterator *iter) +static enum print_line_t mmio_print_map(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct mmiotrace_map *m = (struct mmiotrace_map *)entry; @@ -227,7 +227,7 @@ static int mmio_print_map(struct trace_iterator *iter) unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; - int ret = 1; + int ret; switch (m->opcode) { case MMIO_PROBE: @@ -247,11 +247,11 @@ static int mmio_print_map(struct trace_iterator *iter) break; } if (ret) - return 1; - return 0; + return TRACE_TYPE_HANDLED; + return TRACE_TYPE_PARTIAL_LINE; } -static int mmio_print_mark(struct trace_iterator *iter) +static enum print_line_t mmio_print_mark(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct print_entry *print = (struct print_entry *)entry; @@ -265,16 +265,15 @@ static int mmio_print_mark(struct trace_iterator *iter) /* The trailing newline must be in the message. */ ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; if (entry->flags & TRACE_FLAG_CONT) trace_seq_print_cont(s, iter); - return 1; + return TRACE_TYPE_HANDLED; } -/* return 0 to abort printing without consuming current entry in pipe mode */ -static int mmio_print_line(struct trace_iterator *iter) +static enum print_line_t mmio_print_line(struct trace_iterator *iter) { switch (iter->ent->type) { case TRACE_MMIO_RW: @@ -284,7 +283,7 @@ static int mmio_print_line(struct trace_iterator *iter) case TRACE_PRINT: return mmio_print_mark(iter); default: - return 1; /* ignore unknown entries */ + return TRACE_TYPE_HANDLED; /* ignore unknown entries */ } } -- cgit v1.1 From 9e9efffb7848fe53c334996819139b431b983ac2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 29 Sep 2008 20:31:58 +0200 Subject: tracing/ftrace: adapt the boot tracer to the new print_line type This patch adapts the boot tracer to the new type of the print_line callback. It still relays entries it doesn't support to default output functions. Signed-off-by: Frederic Weisbecker Acked-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index fa8cca1..43bde20 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -45,22 +45,25 @@ static void boot_trace_ctrl_update(struct trace_array *tr) stop_boot_trace(tr); } -static int initcall_print_line(struct trace_iterator *iter) +static enum print_line_t initcall_print_line(struct trace_iterator *iter) { - int ret = 0; + int ret; struct trace_entry *entry = iter->ent; struct trace_boot *field = (struct trace_boot *)entry; struct boot_trace *it = &field->initcall; struct trace_seq *s = &iter->seq; - if (entry->type == TRACE_BOOT) + if (entry->type == TRACE_BOOT) { ret = trace_seq_printf(s, "%pF called from %i " "returned %d after %lld msecs\n", it->func, it->caller, it->result, it->duration); - if (ret) - return 1; - return 0; + if (ret) + return TRACE_TYPE_HANDLED; + else + return TRACE_TYPE_PARTIAL_LINE; + } + return TRACE_TYPE_UNHANDLED; } struct tracer boot_tracer __read_mostly = -- cgit v1.1 From 70255b5e3f1bd1a5af5b1e425ec2c4db7c735112 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Oct 2008 00:29:52 -0400 Subject: ring_buffer: remove raw from local_irq_save The raw_local_irq_save causes issues with lockdep. We don't need it so replace them with local_irq_save. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index cfa7113..8e7392f 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -847,7 +847,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, if (atomic_read(&buffer->record_disabled)) return NULL; - raw_local_irq_save(*flags); + local_irq_save(*flags); cpu = raw_smp_processor_id(); if (!cpu_isset(cpu, buffer->cpumask)) @@ -909,7 +909,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer, rb_commit(cpu_buffer, event); spin_unlock(&cpu_buffer->lock); - raw_local_irq_restore(flags); + local_irq_restore(flags); return 0; } @@ -1583,13 +1583,13 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) if (!cpu_isset(cpu, buffer->cpumask)) return; - raw_local_irq_save(flags); + local_irq_save(flags); spin_lock(&cpu_buffer->lock); rb_reset_cpu(cpu_buffer); spin_unlock(&cpu_buffer->lock); - raw_local_irq_restore(flags); + local_irq_restore(flags); } /** -- cgit v1.1 From d769041f865330034131525ee6a7f72eb4af2a24 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Oct 2008 00:29:53 -0400 Subject: ring_buffer: implement new locking The old "lock always" scheme had issues with lockdep, and was not very efficient anyways. This patch does a new design to be partially lockless on writes. Writes will add new entries to the per cpu pages by simply disabling interrupts. When a write needs to go to another page than it will grab the lock. A new "read page" has been added so that the reader can pull out a page from the ring buffer to read without worrying about the writer writing over it. This allows us to not take the lock for all reads. The lock is now only taken when a read needs to go to a new page. This is far from lockless, and interrupts still need to be disabled, but it is a step towards a more lockless solution, and it also solves a lot of the issues that were noticed by the first conversion of ftrace to the ring buffers. Note: the ring_buffer_{un}lock API has been removed. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 298 ++++++++++++++++++++++++++------------------- kernel/trace/trace.c | 113 +++++++++++------ 2 files changed, 247 insertions(+), 164 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 8e7392f..9631abf 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -161,8 +161,10 @@ struct ring_buffer_per_cpu { struct list_head pages; unsigned long head; /* read from head */ unsigned long tail; /* write to tail */ + unsigned long reader; struct buffer_page *head_page; struct buffer_page *tail_page; + struct buffer_page *reader_page; unsigned long overrun; unsigned long entries; u64 write_stamp; @@ -260,6 +262,7 @@ static struct ring_buffer_per_cpu * rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; + unsigned long addr; int ret; cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()), @@ -272,9 +275,16 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) spin_lock_init(&cpu_buffer->lock); INIT_LIST_HEAD(&cpu_buffer->pages); + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto fail_free_buffer; + cpu_buffer->reader_page = (struct buffer_page *)virt_to_page(addr); + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + cpu_buffer->reader_page->size = 0; + ret = rb_allocate_pages(cpu_buffer, buffer->pages); if (ret < 0) - goto fail_free_buffer; + goto fail_free_reader; cpu_buffer->head_page = list_entry(cpu_buffer->pages.next, struct buffer_page, list); @@ -283,6 +293,9 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) return cpu_buffer; + fail_free_reader: + free_buffer_page(cpu_buffer->reader_page); + fail_free_buffer: kfree(cpu_buffer); return NULL; @@ -293,6 +306,9 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) struct list_head *head = &cpu_buffer->pages; struct buffer_page *page, *tmp; + list_del_init(&cpu_buffer->reader_page->list); + free_buffer_page(cpu_buffer->reader_page); + list_for_each_entry_safe(page, tmp, head, list) { list_del_init(&page->list); free_buffer_page(page); @@ -538,8 +554,10 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) { - return cpu_buffer->head_page == cpu_buffer->tail_page && - cpu_buffer->head == cpu_buffer->tail; + return (cpu_buffer->reader == cpu_buffer->reader_page->size && + (cpu_buffer->tail_page == cpu_buffer->reader_page || + (cpu_buffer->tail_page == cpu_buffer->head_page && + cpu_buffer->head == cpu_buffer->tail))); } static inline int rb_null_event(struct ring_buffer_event *event) @@ -555,10 +573,10 @@ static inline void *rb_page_index(struct buffer_page *page, unsigned index) } static inline struct ring_buffer_event * -rb_head_event(struct ring_buffer_per_cpu *cpu_buffer) +rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer) { - return rb_page_index(cpu_buffer->head_page, - cpu_buffer->head); + return rb_page_index(cpu_buffer->reader_page, + cpu_buffer->reader); } static inline struct ring_buffer_event * @@ -610,15 +628,32 @@ rb_add_stamp(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) cpu_buffer->write_stamp = *ts; } -static void rb_reset_read_page(struct ring_buffer_per_cpu *cpu_buffer) +static void rb_reset_head_page(struct ring_buffer_per_cpu *cpu_buffer) { - cpu_buffer->read_stamp = cpu_buffer->head_page->time_stamp; cpu_buffer->head = 0; } -static void -rb_reset_iter_read_page(struct ring_buffer_iter *iter) +static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { + cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp; + cpu_buffer->reader = 0; +} + +static inline void rb_inc_iter(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + /* + * The iterator could be on the reader page (it starts there). + * But the head could have moved, since the reader was + * found. Check for this case and assign the iterator + * to the head page instead of next. + */ + if (iter->head_page == cpu_buffer->reader_page) + iter->head_page = cpu_buffer->head_page; + else + rb_inc_page(cpu_buffer, &iter->head_page); + iter->read_stamp = iter->head_page->time_stamp; iter->head = 0; } @@ -693,30 +728,39 @@ static struct ring_buffer_event * __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, unsigned type, unsigned long length, u64 *ts) { - struct buffer_page *head_page, *tail_page; + struct buffer_page *tail_page, *head_page, *reader_page; unsigned long tail; struct ring_buffer *buffer = cpu_buffer->buffer; struct ring_buffer_event *event; + /* No locking needed for tail page */ tail_page = cpu_buffer->tail_page; - head_page = cpu_buffer->head_page; tail = cpu_buffer->tail; if (tail + length > BUF_PAGE_SIZE) { struct buffer_page *next_page = tail_page; + spin_lock(&cpu_buffer->lock); rb_inc_page(cpu_buffer, &next_page); + head_page = cpu_buffer->head_page; + reader_page = cpu_buffer->reader_page; + + /* we grabbed the lock before incrementing */ + WARN_ON(next_page == reader_page); + if (next_page == head_page) { - if (!(buffer->flags & RB_FL_OVERWRITE)) + if (!(buffer->flags & RB_FL_OVERWRITE)) { + spin_unlock(&cpu_buffer->lock); return NULL; + } /* count overflows */ rb_update_overflow(cpu_buffer); rb_inc_page(cpu_buffer, &head_page); cpu_buffer->head_page = head_page; - rb_reset_read_page(cpu_buffer); + rb_reset_head_page(cpu_buffer); } if (tail != BUF_PAGE_SIZE) { @@ -732,6 +776,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, cpu_buffer->tail_page = tail_page; cpu_buffer->tail = tail; rb_add_stamp(cpu_buffer, ts); + spin_unlock(&cpu_buffer->lock); } BUG_ON(tail + length > BUF_PAGE_SIZE); @@ -802,7 +847,9 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, return NULL; } } else { + spin_lock(&cpu_buffer->lock); rb_add_stamp(cpu_buffer, &ts); + spin_unlock(&cpu_buffer->lock); delta = 0; } @@ -851,13 +898,12 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, cpu = raw_smp_processor_id(); if (!cpu_isset(cpu, buffer->cpumask)) - goto out_irq; + goto out; cpu_buffer = buffer->buffers[cpu]; - spin_lock(&cpu_buffer->lock); if (atomic_read(&cpu_buffer->record_disabled)) - goto no_record; + goto out; length = rb_calculate_event_length(length); if (length > BUF_PAGE_SIZE) @@ -865,13 +911,11 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length); if (!event) - goto no_record; + goto out; return event; - no_record: - spin_unlock(&cpu_buffer->lock); - out_irq: + out: local_irq_restore(*flags); return NULL; } @@ -904,11 +948,8 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer, cpu_buffer = buffer->buffers[cpu]; - assert_spin_locked(&cpu_buffer->lock); - rb_commit(cpu_buffer, event); - spin_unlock(&cpu_buffer->lock); local_irq_restore(flags); return 0; @@ -945,10 +986,9 @@ int ring_buffer_write(struct ring_buffer *buffer, cpu = raw_smp_processor_id(); if (!cpu_isset(cpu, buffer->cpumask)) - goto out_irq; + goto out; cpu_buffer = buffer->buffers[cpu]; - spin_lock(&cpu_buffer->lock); if (atomic_read(&cpu_buffer->record_disabled)) goto out; @@ -967,56 +1007,12 @@ int ring_buffer_write(struct ring_buffer *buffer, ret = 0; out: - spin_unlock(&cpu_buffer->lock); - out_irq: local_irq_restore(flags); return ret; } /** - * ring_buffer_lock - lock the ring buffer - * @buffer: The ring buffer to lock - * @flags: The place to store the interrupt flags - * - * This locks all the per CPU buffers. - * - * Must be unlocked by ring_buffer_unlock. - */ -void ring_buffer_lock(struct ring_buffer *buffer, unsigned long *flags) -{ - struct ring_buffer_per_cpu *cpu_buffer; - int cpu; - - local_irq_save(*flags); - - for_each_buffer_cpu(buffer, cpu) { - cpu_buffer = buffer->buffers[cpu]; - spin_lock(&cpu_buffer->lock); - } -} - -/** - * ring_buffer_unlock - unlock a locked buffer - * @buffer: The locked buffer to unlock - * @flags: The interrupt flags received by ring_buffer_lock - */ -void ring_buffer_unlock(struct ring_buffer *buffer, unsigned long flags) -{ - struct ring_buffer_per_cpu *cpu_buffer; - int cpu; - - for (cpu = buffer->cpus - 1; cpu >= 0; cpu--) { - if (!cpu_isset(cpu, buffer->cpumask)) - continue; - cpu_buffer = buffer->buffers[cpu]; - spin_unlock(&cpu_buffer->lock); - } - - local_irq_restore(flags); -} - -/** * ring_buffer_record_disable - stop all writes into the buffer * @buffer: The ring buffer to stop writes to. * @@ -1169,9 +1165,18 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter) { struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; - iter->head_page = cpu_buffer->head_page; - iter->head = cpu_buffer->head; - rb_reset_iter_read_page(iter); + /* Iterator usage is expected to have record disabled */ + if (list_empty(&cpu_buffer->reader_page->list)) { + iter->head_page = cpu_buffer->head_page; + iter->head = cpu_buffer->head; + } else { + iter->head_page = cpu_buffer->reader_page; + iter->head = cpu_buffer->reader; + } + if (iter->head) + iter->read_stamp = cpu_buffer->read_stamp; + else + iter->read_stamp = iter->head_page->time_stamp; } /** @@ -1250,43 +1255,84 @@ rb_update_iter_read_stamp(struct ring_buffer_iter *iter, return; } -static void rb_advance_head(struct ring_buffer_per_cpu *cpu_buffer) +static struct buffer_page * +rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { - struct ring_buffer_event *event; - unsigned length; + struct buffer_page *reader = NULL; + unsigned long flags; + + spin_lock_irqsave(&cpu_buffer->lock, flags); + + again: + reader = cpu_buffer->reader_page; + + /* If there's more to read, return this page */ + if (cpu_buffer->reader < reader->size) + goto out; + + /* Never should we have an index greater than the size */ + WARN_ON(cpu_buffer->reader > reader->size); + + /* check if we caught up to the tail */ + reader = NULL; + if (cpu_buffer->tail_page == cpu_buffer->reader_page) + goto out; /* - * Check if we are at the end of the buffer. + * Splice the empty reader page into the list around the head. + * Reset the reader page to size zero. */ - if (cpu_buffer->head >= cpu_buffer->head_page->size) { - BUG_ON(cpu_buffer->head_page == cpu_buffer->tail_page); - rb_inc_page(cpu_buffer, &cpu_buffer->head_page); - rb_reset_read_page(cpu_buffer); - return; - } - event = rb_head_event(cpu_buffer); + reader = cpu_buffer->head_page; + cpu_buffer->reader_page->list.next = reader->list.next; + cpu_buffer->reader_page->list.prev = reader->list.prev; + cpu_buffer->reader_page->size = 0; - if (event->type == RINGBUF_TYPE_DATA) - cpu_buffer->entries--; - - length = rb_event_length(event); + /* Make the reader page now replace the head */ + reader->list.prev->next = &cpu_buffer->reader_page->list; + reader->list.next->prev = &cpu_buffer->reader_page->list; /* - * This should not be called to advance the header if we are - * at the tail of the buffer. + * If the tail is on the reader, then we must set the head + * to the inserted page, otherwise we set it one before. */ - BUG_ON((cpu_buffer->head_page == cpu_buffer->tail_page) && - (cpu_buffer->head + length > cpu_buffer->tail)); + cpu_buffer->head_page = cpu_buffer->reader_page; - rb_update_read_stamp(cpu_buffer, event); + if (cpu_buffer->tail_page != reader) + rb_inc_page(cpu_buffer, &cpu_buffer->head_page); + + /* Finally update the reader page to the new head */ + cpu_buffer->reader_page = reader; + rb_reset_reader_page(cpu_buffer); + + goto again; + + out: + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + + return reader; +} + +static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct ring_buffer_event *event; + struct buffer_page *reader; + unsigned length; + + reader = rb_get_reader_page(cpu_buffer); - cpu_buffer->head += length; + /* This function should not be called when buffer is empty */ + BUG_ON(!reader); - /* check for end of page */ - if ((cpu_buffer->head >= cpu_buffer->head_page->size) && - (cpu_buffer->head_page != cpu_buffer->tail_page)) - rb_advance_head(cpu_buffer); + event = rb_reader_event(cpu_buffer); + + if (event->type == RINGBUF_TYPE_DATA) + cpu_buffer->entries--; + + rb_update_read_stamp(cpu_buffer, event); + + length = rb_event_length(event); + cpu_buffer->reader += length; } static void rb_advance_iter(struct ring_buffer_iter *iter) @@ -1304,8 +1350,7 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) */ if (iter->head >= iter->head_page->size) { BUG_ON(iter->head_page == cpu_buffer->tail_page); - rb_inc_page(cpu_buffer, &iter->head_page); - rb_reset_iter_read_page(iter); + rb_inc_iter(iter); return; } @@ -1344,6 +1389,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; + struct buffer_page *reader; if (!cpu_isset(cpu, buffer->cpumask)) return NULL; @@ -1351,25 +1397,26 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) cpu_buffer = buffer->buffers[cpu]; again: - if (rb_per_cpu_empty(cpu_buffer)) + reader = rb_get_reader_page(cpu_buffer); + if (!reader) return NULL; - event = rb_head_event(cpu_buffer); + event = rb_reader_event(cpu_buffer); switch (event->type) { case RINGBUF_TYPE_PADDING: - rb_inc_page(cpu_buffer, &cpu_buffer->head_page); - rb_reset_read_page(cpu_buffer); - goto again; + WARN_ON(1); + rb_advance_reader(cpu_buffer); + return NULL; case RINGBUF_TYPE_TIME_EXTEND: /* Internal data, OK to advance */ - rb_advance_head(cpu_buffer); + rb_advance_reader(cpu_buffer); goto again; case RINGBUF_TYPE_TIME_STAMP: /* FIXME: not implemented */ - rb_advance_head(cpu_buffer); + rb_advance_reader(cpu_buffer); goto again; case RINGBUF_TYPE_DATA: @@ -1415,8 +1462,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) switch (event->type) { case RINGBUF_TYPE_PADDING: - rb_inc_page(cpu_buffer, &iter->head_page); - rb_reset_iter_read_page(iter); + rb_inc_iter(iter); goto again; case RINGBUF_TYPE_TIME_EXTEND: @@ -1465,7 +1511,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) return NULL; cpu_buffer = buffer->buffers[cpu]; - rb_advance_head(cpu_buffer); + rb_advance_reader(cpu_buffer); return event; } @@ -1487,6 +1533,7 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_iter *iter; + unsigned long flags; if (!cpu_isset(cpu, buffer->cpumask)) return NULL; @@ -1502,11 +1549,9 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu) atomic_inc(&cpu_buffer->record_disabled); synchronize_sched(); - spin_lock(&cpu_buffer->lock); - iter->head = cpu_buffer->head; - iter->head_page = cpu_buffer->head_page; - rb_reset_iter_read_page(iter); - spin_unlock(&cpu_buffer->lock); + spin_lock_irqsave(&cpu_buffer->lock, flags); + ring_buffer_iter_reset(iter); + spin_unlock_irqrestore(&cpu_buffer->lock, flags); return iter; } @@ -1562,10 +1607,14 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) { cpu_buffer->head_page = list_entry(cpu_buffer->pages.next, struct buffer_page, list); - cpu_buffer->tail_page - = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + cpu_buffer->head_page->size = 0; + cpu_buffer->tail_page = cpu_buffer->head_page; + cpu_buffer->tail_page->size = 0; + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + cpu_buffer->reader_page->size = 0; + + cpu_buffer->head = cpu_buffer->tail = cpu_buffer->reader = 0; - cpu_buffer->head = cpu_buffer->tail = 0; cpu_buffer->overrun = 0; cpu_buffer->entries = 0; } @@ -1583,13 +1632,11 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) if (!cpu_isset(cpu, buffer->cpumask)) return; - local_irq_save(flags); - spin_lock(&cpu_buffer->lock); + spin_lock_irqsave(&cpu_buffer->lock, flags); rb_reset_cpu(cpu_buffer); - spin_unlock(&cpu_buffer->lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&cpu_buffer->lock, flags); } /** @@ -1598,15 +1645,10 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) */ void ring_buffer_reset(struct ring_buffer *buffer) { - unsigned long flags; int cpu; - ring_buffer_lock(buffer, &flags); - for_each_buffer_cpu(buffer, cpu) - rb_reset_cpu(buffer->buffers[cpu]); - - ring_buffer_unlock(buffer, flags); + ring_buffer_reset_cpu(buffer, cpu); } /** diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6a1c76b..b542f88 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -42,6 +42,20 @@ unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; unsigned long __read_mostly tracing_thresh; +static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled); + +static inline void ftrace_disable_cpu(void) +{ + preempt_disable(); + local_inc(&__get_cpu_var(ftrace_cpu_disabled)); +} + +static inline void ftrace_enable_cpu(void) +{ + local_dec(&__get_cpu_var(ftrace_cpu_disabled)); + preempt_enable(); +} + static cpumask_t __read_mostly tracing_buffer_mask; #define for_each_tracing_cpu(cpu) \ @@ -406,7 +420,9 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) tr->buffer = max_tr.buffer; max_tr.buffer = buf; + ftrace_disable_cpu(); ring_buffer_reset(tr->buffer); + ftrace_enable_cpu(); __update_max_tr(tr, tsk, cpu); __raw_spin_unlock(&ftrace_max_lock); @@ -428,9 +444,13 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) WARN_ON_ONCE(!irqs_disabled()); __raw_spin_lock(&ftrace_max_lock); + ftrace_disable_cpu(); + ring_buffer_reset(max_tr.buffer); ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); + ftrace_enable_cpu(); + WARN_ON_ONCE(ret); __update_max_tr(tr, tsk, cpu); @@ -543,7 +563,9 @@ void unregister_tracer(struct tracer *type) void tracing_reset(struct trace_array *tr, int cpu) { + ftrace_disable_cpu(); ring_buffer_reset_cpu(tr->buffer, cpu); + ftrace_enable_cpu(); } #define SAVED_CMDLINES 128 @@ -654,6 +676,10 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, struct ftrace_entry *entry; unsigned long irq_flags; + /* If we are reading the ring buffer, don't trace */ + if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) + return; + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq_flags); if (!event) @@ -870,8 +896,14 @@ enum trace_file_type { static void trace_iterator_increment(struct trace_iterator *iter, int cpu) { + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); + iter->idx++; - ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + if (iter->buffer_iter[iter->cpu]) + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + + ftrace_enable_cpu(); } static struct trace_entry * @@ -880,9 +912,19 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) struct ring_buffer_event *event; struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; - event = ring_buffer_iter_peek(buf_iter, ts); + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); + + if (buf_iter) + event = ring_buffer_iter_peek(buf_iter, ts); + else + event = ring_buffer_peek(iter->tr->buffer, cpu, ts); + + ftrace_enable_cpu(); + return event ? ring_buffer_event_data(event) : NULL; } + static struct trace_entry * __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { @@ -938,7 +980,10 @@ static void *find_next_entry_inc(struct trace_iterator *iter) static void trace_consume(struct trace_iterator *iter) { + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); + ftrace_enable_cpu(); } static void *s_next(struct seq_file *m, void *v, loff_t *pos) @@ -991,10 +1036,14 @@ static void *s_start(struct seq_file *m, loff_t *pos) iter->cpu = 0; iter->idx = -1; + ftrace_disable_cpu(); + for_each_tracing_cpu(cpu) { ring_buffer_iter_reset(iter->buffer_iter[cpu]); } + ftrace_enable_cpu(); + for (p = iter; p && l < *pos; p = s_next(m, p, &l)) ; @@ -1242,7 +1291,16 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) cont = (struct trace_field_cont *)ent; if (ok) ok = (trace_seq_printf(s, "%s", cont->buf) > 0); - ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + + ftrace_disable_cpu(); + + if (iter->buffer_iter[iter->cpu]) + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + else + ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL); + + ftrace_enable_cpu(); + ent = peek_next_entry(iter, iter->cpu, NULL); } while (ent && ent->type == TRACE_CONT); @@ -1683,9 +1741,15 @@ static int trace_empty(struct trace_iterator *iter) int cpu; for_each_tracing_cpu(cpu) { - if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) - return 0; + if (iter->buffer_iter[cpu]) { + if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) + return 0; + } else { + if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) + return 0; + } } + return TRACE_TYPE_HANDLED; } @@ -1776,8 +1840,10 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) iter->pos = -1; for_each_tracing_cpu(cpu) { + iter->buffer_iter[cpu] = ring_buffer_read_start(iter->tr->buffer, cpu); + if (!iter->buffer_iter[cpu]) goto fail_buffer; } @@ -2341,7 +2407,6 @@ static atomic_t tracing_reader; static int tracing_open_pipe(struct inode *inode, struct file *filp) { struct trace_iterator *iter; - int cpu; if (tracing_disabled) return -ENODEV; @@ -2362,38 +2427,17 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) iter->trace = current_trace; filp->private_data = iter; - for_each_tracing_cpu(cpu) { - iter->buffer_iter[cpu] = - ring_buffer_read_start(iter->tr->buffer, cpu); - if (!iter->buffer_iter[cpu]) - goto fail_buffer; - } - if (iter->trace->pipe_open) iter->trace->pipe_open(iter); mutex_unlock(&trace_types_lock); return 0; - - fail_buffer: - for_each_tracing_cpu(cpu) { - if (iter->buffer_iter[cpu]) - ring_buffer_read_finish(iter->buffer_iter[cpu]); - } - mutex_unlock(&trace_types_lock); - - return -ENOMEM; } static int tracing_release_pipe(struct inode *inode, struct file *file) { struct trace_iterator *iter = file->private_data; - int cpu; - for_each_tracing_cpu(cpu) { - if (iter->buffer_iter[cpu]) - ring_buffer_read_finish(iter->buffer_iter[cpu]); - } kfree(iter); atomic_dec(&tracing_reader); @@ -2429,7 +2473,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; - unsigned long flags; #ifdef CONFIG_FTRACE int ftrace_save; #endif @@ -2528,7 +2571,6 @@ waitagain: ftrace_enabled = 0; #endif smp_wmb(); - ring_buffer_lock(iter->tr->buffer, &flags); while (find_next_entry_inc(iter) != NULL) { enum print_line_t ret; @@ -2547,7 +2589,6 @@ waitagain: break; } - ring_buffer_unlock(iter->tr->buffer, flags); #ifdef CONFIG_FTRACE ftrace_enabled = ftrace_save; #endif @@ -3010,8 +3051,8 @@ void ftrace_dump(void) static struct trace_iterator iter; static cpumask_t mask; static int dump_ran; - unsigned long flags, irq_flags; - int cnt = 0; + unsigned long flags; + int cnt = 0, cpu; /* only one dump */ spin_lock_irqsave(&ftrace_dump_lock, flags); @@ -3023,6 +3064,10 @@ void ftrace_dump(void) /* No turning back! */ ftrace_kill_atomic(); + for_each_tracing_cpu(cpu) { + atomic_inc(&global_trace.data[cpu]->disabled); + } + printk(KERN_TRACE "Dumping ftrace buffer:\n"); iter.tr = &global_trace; @@ -3037,8 +3082,6 @@ void ftrace_dump(void) cpus_clear(mask); - ring_buffer_lock(iter.tr->buffer, &irq_flags); - while (!trace_empty(&iter)) { if (!cnt) @@ -3066,8 +3109,6 @@ void ftrace_dump(void) else printk(KERN_TRACE "---------------------------------\n"); - ring_buffer_unlock(iter.tr->buffer, irq_flags); - out: spin_unlock_irqrestore(&ftrace_dump_lock, flags); } -- cgit v1.1 From 797d3712a9dd75c720558612be05f42c031a7bb5 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 30 Sep 2008 18:13:45 +0200 Subject: tracing/ftrace: adapt mmiotrace to the new type of print_line, fix Correct the value's type of trace_empty function Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b542f88..c163406 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1750,7 +1750,7 @@ static int trace_empty(struct trace_iterator *iter) } } - return TRACE_TYPE_HANDLED; + return 1; } static enum print_line_t print_trace_line(struct trace_iterator *iter) -- cgit v1.1 From 7104f300c5a69b46dda00d898034dd05c9f21739 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Oct 2008 10:52:51 -0400 Subject: ftrace: type cast filter+verifier The mmiotrace map had a bug that would typecast the entry from the trace to the wrong type. That is a known danger of C typecasts, there's absolutely zero checking done on them. Help that problem a bit by using a GCC extension to implement a type filter that restricts the types that a trace record can be cast into, and by adding a dynamic check (in debug mode) to verify the type of the entry. This patch adds a macro to assign all entries of ftrace using the type of the variable and checking the entry id. The typecasts are now done in the macro for only those types that it knows about, which should be all the types that are allowed to be read from the tracer. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 85 +++++++++++++++++++++++++++++------------- kernel/trace/trace.h | 42 +++++++++++++++++++++ kernel/trace/trace_mmiotrace.c | 14 +++++-- 3 files changed, 112 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c163406..948f7d8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1350,7 +1350,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) } switch (entry->type) { case TRACE_FN: { - struct ftrace_entry *field = (struct ftrace_entry *)entry; + struct ftrace_entry *field; + + trace_assign_type(field, entry); seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_puts(s, " ("); @@ -1363,8 +1365,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) } case TRACE_CTX: case TRACE_WAKE: { - struct ctx_switch_entry *field = - (struct ctx_switch_entry *)entry; + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); T = field->next_state < sizeof(state_to_char) ? state_to_char[field->next_state] : 'X'; @@ -1384,7 +1387,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) break; } case TRACE_SPECIAL: { - struct special_entry *field = (struct special_entry *)entry; + struct special_entry *field; + + trace_assign_type(field, entry); trace_seq_printf(s, "# %ld %ld %ld\n", field->arg1, @@ -1393,7 +1398,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) break; } case TRACE_STACK: { - struct stack_entry *field = (struct stack_entry *)entry; + struct stack_entry *field; + + trace_assign_type(field, entry); for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) @@ -1404,7 +1411,9 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) break; } case TRACE_PRINT: { - struct print_entry *field = (struct print_entry *)entry; + struct print_entry *field; + + trace_assign_type(field, entry); seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_printf(s, ": %s", field->buf); @@ -1454,7 +1463,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) switch (entry->type) { case TRACE_FN: { - struct ftrace_entry *field = (struct ftrace_entry *)entry; + struct ftrace_entry *field; + + trace_assign_type(field, entry); ret = seq_print_ip_sym(s, field->ip, sym_flags); if (!ret) @@ -1480,8 +1491,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) } case TRACE_CTX: case TRACE_WAKE: { - struct ctx_switch_entry *field = - (struct ctx_switch_entry *)entry; + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); S = field->prev_state < sizeof(state_to_char) ? state_to_char[field->prev_state] : 'X'; @@ -1501,7 +1513,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) break; } case TRACE_SPECIAL: { - struct special_entry *field = (struct special_entry *)entry; + struct special_entry *field; + + trace_assign_type(field, entry); ret = trace_seq_printf(s, "# %ld %ld %ld\n", field->arg1, @@ -1512,7 +1526,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) break; } case TRACE_STACK: { - struct stack_entry *field = (struct stack_entry *)entry; + struct stack_entry *field; + + trace_assign_type(field, entry); for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) { @@ -1531,7 +1547,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) break; } case TRACE_PRINT: { - struct print_entry *field = (struct print_entry *)entry; + struct print_entry *field; + + trace_assign_type(field, entry); seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_printf(s, ": %s", field->buf); @@ -1562,7 +1580,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter) switch (entry->type) { case TRACE_FN: { - struct ftrace_entry *field = (struct ftrace_entry *)entry; + struct ftrace_entry *field; + + trace_assign_type(field, entry); ret = trace_seq_printf(s, "%x %x\n", field->ip, @@ -1573,8 +1593,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter) } case TRACE_CTX: case TRACE_WAKE: { - struct ctx_switch_entry *field = - (struct ctx_switch_entry *)entry; + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); S = field->prev_state < sizeof(state_to_char) ? state_to_char[field->prev_state] : 'X'; @@ -1596,7 +1617,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter) } case TRACE_SPECIAL: case TRACE_STACK: { - struct special_entry *field = (struct special_entry *)entry; + struct special_entry *field; + + trace_assign_type(field, entry); ret = trace_seq_printf(s, "# %ld %ld %ld\n", field->arg1, @@ -1607,7 +1630,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter) break; } case TRACE_PRINT: { - struct print_entry *field = (struct print_entry *)entry; + struct print_entry *field; + + trace_assign_type(field, entry); trace_seq_printf(s, "# %lx %s", field->ip, field->buf); if (entry->flags & TRACE_FLAG_CONT) @@ -1648,7 +1673,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter) switch (entry->type) { case TRACE_FN: { - struct ftrace_entry *field = (struct ftrace_entry *)entry; + struct ftrace_entry *field; + + trace_assign_type(field, entry); SEQ_PUT_HEX_FIELD_RET(s, field->ip); SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip); @@ -1656,8 +1683,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter) } case TRACE_CTX: case TRACE_WAKE: { - struct ctx_switch_entry *field = - (struct ctx_switch_entry *)entry; + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); S = field->prev_state < sizeof(state_to_char) ? state_to_char[field->prev_state] : 'X'; @@ -1676,7 +1704,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter) } case TRACE_SPECIAL: case TRACE_STACK: { - struct special_entry *field = (struct special_entry *)entry; + struct special_entry *field; + + trace_assign_type(field, entry); SEQ_PUT_HEX_FIELD_RET(s, field->arg1); SEQ_PUT_HEX_FIELD_RET(s, field->arg2); @@ -1705,15 +1735,18 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter) switch (entry->type) { case TRACE_FN: { - struct ftrace_entry *field = (struct ftrace_entry *)entry; + struct ftrace_entry *field; + + trace_assign_type(field, entry); SEQ_PUT_FIELD_RET(s, field->ip); SEQ_PUT_FIELD_RET(s, field->parent_ip); break; } case TRACE_CTX: { - struct ctx_switch_entry *field = - (struct ctx_switch_entry *)entry; + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); SEQ_PUT_FIELD_RET(s, field->prev_pid); SEQ_PUT_FIELD_RET(s, field->prev_prio); @@ -1725,7 +1758,9 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter) } case TRACE_SPECIAL: case TRACE_STACK: { - struct special_entry *field = (struct special_entry *)entry; + struct special_entry *field; + + trace_assign_type(field, entry); SEQ_PUT_FIELD_RET(s, field->arg1); SEQ_PUT_FIELD_RET(s, field->arg2); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index a921ba5..f02042d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -177,6 +177,48 @@ struct trace_array { struct trace_array_cpu *data[NR_CPUS]; }; +#define FTRACE_CMP_TYPE(var, type) \ + __builtin_types_compatible_p(typeof(var), type *) + +#undef IF_ASSIGN +#define IF_ASSIGN(var, entry, etype, id) \ + if (FTRACE_CMP_TYPE(var, etype)) { \ + var = (typeof(var))(entry); \ + WARN_ON(id && (entry)->type != id); \ + break; \ + } + +/* Will cause compile errors if type is not found. */ +extern void __ftrace_bad_type(void); + +/* + * The trace_assign_type is a verifier that the entry type is + * the same as the type being assigned. To add new types simply + * add a line with the following format: + * + * IF_ASSIGN(var, ent, type, id); + * + * Where "type" is the trace type that includes the trace_entry + * as the "ent" item. And "id" is the trace identifier that is + * used in the trace_type enum. + * + * If the type can have more than one id, then use zero. + */ +#define trace_assign_type(var, ent) \ + do { \ + IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ + IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ + IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \ + IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ + IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ + IF_ASSIGN(var, ent, struct special_entry, 0); \ + IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ + TRACE_MMIO_RW); \ + IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ + TRACE_MMIO_MAP); \ + IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \ + __ftrace_bad_type(); \ + } while (0) /* Return values for print_line callback */ enum print_line_t { diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 1a266aa..0e819f4 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -178,15 +178,17 @@ print_out: static enum print_line_t mmio_print_rw(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct trace_mmiotrace_rw *field = - (struct trace_mmiotrace_rw *)entry; - struct mmiotrace_rw *rw = &field->rw; + struct trace_mmiotrace_rw *field; + struct mmiotrace_rw *rw; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; + trace_assign_type(field, entry); + rw = &field->rw; + switch (rw->opcode) { case MMIO_READ: ret = trace_seq_printf(s, @@ -222,13 +224,17 @@ static enum print_line_t mmio_print_rw(struct trace_iterator *iter) static enum print_line_t mmio_print_map(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_map *m = (struct mmiotrace_map *)entry; + struct trace_mmiotrace_map *field; + struct mmiotrace_map *m; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret; + trace_assign_type(field, entry); + m = &field->map; + switch (m->opcode) { case MMIO_PROBE: ret = trace_seq_printf(s, -- cgit v1.1 From e4c2ce82ca2710e17cb4df8eb2b249fa2eb5af30 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Oct 2008 11:14:54 -0400 Subject: ring_buffer: allocate buffer page pointer The current method of overlaying the page frame as the buffer page pointer can be very dangerous and limits our ability to do other things with a page from the buffer, like send it off to disk. This patch allocates the buffer_page instead of overlaying the page's page frame. The use of the buffer_page has hardly changed due to this. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 54 +++++++++++++++++++++++++++------------------- 1 file changed, 32 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9631abf..9814571 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -115,16 +115,10 @@ void *ring_buffer_event_data(struct ring_buffer_event *event) * Thanks to Peter Zijlstra for suggesting this idea. */ struct buffer_page { - union { - struct { - unsigned long flags; /* mandatory */ - atomic_t _count; /* mandatory */ - u64 time_stamp; /* page time stamp */ - unsigned size; /* size of page data */ - struct list_head list; /* list of free pages */ - }; - struct page page; - }; + u64 time_stamp; /* page time stamp */ + unsigned size; /* size of page data */ + struct list_head list; /* list of free pages */ + void *page; /* Actual data page */ }; /* @@ -133,9 +127,9 @@ struct buffer_page { */ static inline void free_buffer_page(struct buffer_page *bpage) { - reset_page_mapcount(&bpage->page); - bpage->page.mapping = NULL; - __free_page(&bpage->page); + if (bpage->page) + __free_page(bpage->page); + kfree(bpage); } /* @@ -237,11 +231,16 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned i; for (i = 0; i < nr_pages; i++) { + page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!page) + goto free_pages; + list_add(&page->list, &pages); + addr = __get_free_page(GFP_KERNEL); if (!addr) goto free_pages; - page = (struct buffer_page *)virt_to_page(addr); - list_add(&page->list, &pages); + page->page = (void *)addr; } list_splice(&pages, head); @@ -262,6 +261,7 @@ static struct ring_buffer_per_cpu * rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; + struct buffer_page *page; unsigned long addr; int ret; @@ -275,10 +275,17 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) spin_lock_init(&cpu_buffer->lock); INIT_LIST_HEAD(&cpu_buffer->pages); + page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!page) + goto fail_free_buffer; + + cpu_buffer->reader_page = page; addr = __get_free_page(GFP_KERNEL); if (!addr) - goto fail_free_buffer; - cpu_buffer->reader_page = (struct buffer_page *)virt_to_page(addr); + goto fail_free_reader; + page->page = (void *)addr; + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); cpu_buffer->reader_page->size = 0; @@ -523,11 +530,16 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) for_each_buffer_cpu(buffer, cpu) { for (i = 0; i < new_pages; i++) { + page = kzalloc_node(ALIGN(sizeof(*page), + cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!page) + goto free_pages; + list_add(&page->list, &pages); addr = __get_free_page(GFP_KERNEL); if (!addr) goto free_pages; - page = (struct buffer_page *)virt_to_page(addr); - list_add(&page->list, &pages); + page->page = (void *)addr; } } @@ -567,9 +579,7 @@ static inline int rb_null_event(struct ring_buffer_event *event) static inline void *rb_page_index(struct buffer_page *page, unsigned index) { - void *addr = page_address(&page->page); - - return addr + index; + return page->page + index; } static inline struct ring_buffer_event * -- cgit v1.1 From 38697053fa006411224a1790e2adb8216440ab0f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 1 Oct 2008 13:14:09 -0400 Subject: ftrace: preempt disable over interrupt disable With the new ring buffer infrastructure in ftrace, I'm trying to make ftrace a little more light weight. This patch converts a lot of the local_irq_save/restore into preempt_disable/enable. The original preempt count in a lot of cases has to be sent in as a parameter so that it can be recorded correctly. Some places were recording it incorrectly before anyway. This is also laying the ground work to make ftrace a little bit more reentrant, and remove all locking. The function tracers must still protect from reentrancy. Note: All the function tracers must be careful when using preempt_disable. It must do the following: resched = need_resched(); preempt_disable_notrace(); [...] if (resched) preempt_enable_no_resched_notrace(); else preempt_enable_notrace(); The reason is that if this function traces schedule() itself, the preempt_enable_notrace() will cause a schedule, which will lead us into a recursive failure. If we needed to reschedule before calling preempt_disable, we should have already scheduled. Since we did not, this is most likely that we should not and are probably inside a schedule function. If resched was not set, we still need to catch the need resched flag being set when preemption was off and the if case at the end will catch that for us. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 123 +++++++++++++++++++------------------- kernel/trace/trace.h | 13 ++-- kernel/trace/trace_boot.c | 2 +- kernel/trace/trace_irqsoff.c | 13 ++-- kernel/trace/trace_mmiotrace.c | 4 +- kernel/trace/trace_sched_switch.c | 9 ++- kernel/trace/trace_sched_wakeup.c | 13 +++- 7 files changed, 97 insertions(+), 80 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 948f7d8..1cd2e81 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -652,12 +652,10 @@ void tracing_record_cmdline(struct task_struct *tsk) } void -tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) +tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, + int pc) { struct task_struct *tsk = current; - unsigned long pc; - - pc = preempt_count(); entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; @@ -670,7 +668,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) void trace_function(struct trace_array *tr, struct trace_array_cpu *data, - unsigned long ip, unsigned long parent_ip, unsigned long flags) + unsigned long ip, unsigned long parent_ip, unsigned long flags, + int pc) { struct ring_buffer_event *event; struct ftrace_entry *entry; @@ -685,7 +684,7 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, flags); + tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_FN; entry->ip = ip; entry->parent_ip = parent_ip; @@ -694,16 +693,17 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, void ftrace(struct trace_array *tr, struct trace_array_cpu *data, - unsigned long ip, unsigned long parent_ip, unsigned long flags) + unsigned long ip, unsigned long parent_ip, unsigned long flags, + int pc) { if (likely(!atomic_read(&data->disabled))) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); } -void __trace_stack(struct trace_array *tr, - struct trace_array_cpu *data, - unsigned long flags, - int skip) +static void ftrace_trace_stack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags, + int skip, int pc) { struct ring_buffer_event *event; struct stack_entry *entry; @@ -718,7 +718,7 @@ void __trace_stack(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, flags); + tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_STACK; memset(&entry->caller, 0, sizeof(entry->caller)); @@ -732,9 +732,18 @@ void __trace_stack(struct trace_array *tr, ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } -void -__trace_special(void *__tr, void *__data, - unsigned long arg1, unsigned long arg2, unsigned long arg3) +void __trace_stack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags, + int skip) +{ + ftrace_trace_stack(tr, data, flags, skip, preempt_count()); +} + +static void +ftrace_trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3, + int pc) { struct ring_buffer_event *event; struct trace_array_cpu *data = __data; @@ -747,23 +756,30 @@ __trace_special(void *__tr, void *__data, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0); + tracing_generic_entry_update(&entry->ent, 0, pc); entry->ent.type = TRACE_SPECIAL; entry->arg1 = arg1; entry->arg2 = arg2; entry->arg3 = arg3; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - __trace_stack(tr, data, irq_flags, 4); + ftrace_trace_stack(tr, data, irq_flags, 4, pc); trace_wake_up(); } void +__trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count()); +} + +void tracing_sched_switch_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *prev, struct task_struct *next, - unsigned long flags) + unsigned long flags, int pc) { struct ring_buffer_event *event; struct ctx_switch_entry *entry; @@ -774,7 +790,7 @@ tracing_sched_switch_trace(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, flags); + tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_CTX; entry->prev_pid = prev->pid; entry->prev_prio = prev->prio; @@ -784,7 +800,7 @@ tracing_sched_switch_trace(struct trace_array *tr, entry->next_state = next->state; entry->next_cpu = task_cpu(next); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - __trace_stack(tr, data, flags, 5); + ftrace_trace_stack(tr, data, flags, 5, pc); } void @@ -792,7 +808,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *wakee, struct task_struct *curr, - unsigned long flags) + unsigned long flags, int pc) { struct ring_buffer_event *event; struct ctx_switch_entry *entry; @@ -803,7 +819,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, flags); + tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_WAKE; entry->prev_pid = curr->pid; entry->prev_prio = curr->prio; @@ -813,7 +829,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry->next_state = wakee->state; entry->next_cpu = task_cpu(wakee); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); - __trace_stack(tr, data, flags, 6); + ftrace_trace_stack(tr, data, flags, 6, pc); trace_wake_up(); } @@ -823,23 +839,24 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; - unsigned long flags; long disabled; int cpu; + int pc; if (tracing_disabled || !tr->ctrl) return; - local_irq_save(flags); + pc = preempt_count(); + preempt_disable_notrace(); cpu = raw_smp_processor_id(); data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - __trace_special(tr, data, arg1, arg2, arg3); + ftrace_trace_special(tr, data, arg1, arg2, arg3, pc); atomic_dec(&data->disabled); - local_irq_restore(flags); + preempt_enable_notrace(); } #ifdef CONFIG_FTRACE @@ -850,7 +867,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) struct trace_array_cpu *data; unsigned long flags; long disabled; - int cpu; + int cpu, resched; + int pc; if (unlikely(!ftrace_function_enabled)) return; @@ -858,16 +876,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) if (skip_trace(ip)) return; - local_irq_save(flags); + pc = preempt_count(); + resched = need_resched(); + preempt_disable_notrace(); + local_save_flags(flags); cpu = raw_smp_processor_id(); data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); atomic_dec(&data->disabled); - local_irq_restore(flags); + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); } static struct ftrace_ops trace_ops __read_mostly = @@ -2508,9 +2532,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; -#ifdef CONFIG_FTRACE - int ftrace_save; -#endif ssize_t sret; /* return any leftover data */ @@ -2593,20 +2614,6 @@ waitagain: offsetof(struct trace_iterator, seq)); iter->pos = -1; - /* - * We need to stop all tracing on all CPUS to read the - * the next buffer. This is a bit expensive, but is - * not done often. We fill all what we can read, - * and then release the locks again. - */ - - local_irq_disable(); -#ifdef CONFIG_FTRACE - ftrace_save = ftrace_enabled; - ftrace_enabled = 0; -#endif - smp_wmb(); - while (find_next_entry_inc(iter) != NULL) { enum print_line_t ret; int len = iter->seq.len; @@ -2624,11 +2631,6 @@ waitagain: break; } -#ifdef CONFIG_FTRACE - ftrace_enabled = ftrace_save; -#endif - local_irq_enable(); - /* Now copy what we have to the user */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); if (iter->seq.readpos >= iter->seq.len) @@ -2960,12 +2962,13 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) struct print_entry *entry; unsigned long flags, irq_flags; long disabled; - int cpu, len = 0, size; + int cpu, len = 0, size, pc; if (!tr->ctrl || tracing_disabled) return 0; - local_irq_save(flags); + pc = preempt_count(); + preempt_disable_notrace(); cpu = raw_smp_processor_id(); data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); @@ -2973,7 +2976,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) if (unlikely(disabled != 1)) goto out; - spin_lock(&trace_buf_lock); + spin_lock_irqsave(&trace_buf_lock, flags); len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); len = min(len, TRACE_BUF_SIZE-1); @@ -2984,7 +2987,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) if (!event) goto out_unlock; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, flags); + tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_PRINT; entry->ip = ip; @@ -2993,11 +2996,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) ring_buffer_unlock_commit(tr->buffer, event, irq_flags); out_unlock: - spin_unlock(&trace_buf_lock); + spin_unlock_irqrestore(&trace_buf_lock, flags); out: atomic_dec(&data->disabled); - local_irq_restore(flags); + preempt_enable_notrace(); return len; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f02042d..f1f9957 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -288,35 +288,36 @@ void init_tracer_sysprof_debugfs(struct dentry *d_tracer); struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data); void tracing_generic_entry_update(struct trace_entry *entry, - unsigned long flags); + unsigned long flags, + int pc); void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, - unsigned long flags); + unsigned long flags, int pc); void tracing_sched_switch_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *prev, struct task_struct *next, - unsigned long flags); + unsigned long flags, int pc); void tracing_record_cmdline(struct task_struct *tsk); void tracing_sched_wakeup_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *wakee, struct task_struct *cur, - unsigned long flags); + unsigned long flags, int pc); void trace_special(struct trace_array *tr, struct trace_array_cpu *data, unsigned long arg1, unsigned long arg2, - unsigned long arg3); + unsigned long arg3, int pc); void trace_function(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, - unsigned long flags); + unsigned long flags, int pc); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 43bde20..f2dac6f 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -95,7 +95,7 @@ void trace_boot(struct boot_trace *it) if (!event) goto out; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0); + tracing_generic_entry_update(&entry->ent, 0, 0); entry->ent.type = TRACE_BOOT; entry->initcall = *it; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 37ad494..f925dbbf 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -95,7 +95,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); atomic_dec(&data->disabled); } @@ -130,6 +130,7 @@ check_critical_timing(struct trace_array *tr, unsigned long latency, t0, t1; cycle_t T0, T1, delta; unsigned long flags; + int pc; /* * usecs conversion is slow so we try to delay the conversion @@ -144,13 +145,15 @@ check_critical_timing(struct trace_array *tr, if (!report_latency(delta)) goto out; + pc = preempt_count(); + spin_lock_irqsave(&max_trace_lock, flags); /* check if we are still the max latency */ if (!report_latency(delta)) goto out_unlock; - trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc); latency = nsecs_to_usecs(delta); @@ -174,7 +177,7 @@ out: data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); tracing_reset(tr, cpu); - trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc); } static inline void @@ -207,7 +210,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) local_save_flags(flags); - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); per_cpu(tracing_cpu, cpu) = 1; @@ -241,7 +244,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) atomic_inc(&data->disabled); local_save_flags(flags); - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); check_critical_timing(tr, data, parent_ip ? : ip, cpu); data->critical_start = 0; atomic_dec(&data->disabled); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 0e819f4..f284846 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -324,7 +324,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0); + tracing_generic_entry_update(&entry->ent, 0, preempt_count()); entry->ent.type = TRACE_MMIO_RW; entry->rw = *rw; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); @@ -352,7 +352,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr, if (!event) return; entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0); + tracing_generic_entry_update(&entry->ent, 0, preempt_count()); entry->ent.type = TRACE_MMIO_MAP; entry->map = *map; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index e0b06db..c7fa08a 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -26,6 +26,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, unsigned long flags; long disabled; int cpu; + int pc; if (!atomic_read(&sched_ref)) return; @@ -36,13 +37,14 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, if (!tracer_enabled) return; + pc = preempt_count(); local_irq_save(flags); cpu = raw_smp_processor_id(); data = ctx_trace->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - tracing_sched_switch_trace(ctx_trace, data, prev, next, flags); + tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc); atomic_dec(&data->disabled); local_irq_restore(flags); @@ -54,11 +56,12 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) struct trace_array_cpu *data; unsigned long flags; long disabled; - int cpu; + int cpu, pc; if (!likely(tracer_enabled)) return; + pc = preempt_count(); tracing_record_cmdline(current); local_irq_save(flags); @@ -68,7 +71,7 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) if (likely(disabled == 1)) tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, - flags); + flags, pc); atomic_dec(&data->disabled); local_irq_restore(flags); diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 01e75e0..fe4a252 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -44,10 +44,12 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) long disabled; int resched; int cpu; + int pc; if (likely(!wakeup_task)) return; + pc = preempt_count(); resched = need_resched(); preempt_disable_notrace(); @@ -70,7 +72,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) if (task_cpu(wakeup_task) != cpu) goto unlock; - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); unlock: __raw_spin_unlock(&wakeup_lock); @@ -121,6 +123,7 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, unsigned long flags; long disabled; int cpu; + int pc; tracing_record_cmdline(prev); @@ -139,6 +142,8 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, if (next != wakeup_task) return; + pc = preempt_count(); + /* The task we are waiting for is waking up */ data = wakeup_trace->data[wakeup_cpu]; @@ -155,7 +160,7 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, if (unlikely(!tracer_enabled || next != wakeup_task)) goto out_unlock; - trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags); + trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags, pc); /* * usecs conversion is slow so we try to delay the conversion @@ -220,6 +225,7 @@ probe_wakeup(struct rq *rq, struct task_struct *p) int cpu = smp_processor_id(); unsigned long flags; long disabled; + int pc; if (likely(!tracer_enabled)) return; @@ -232,6 +238,7 @@ probe_wakeup(struct rq *rq, struct task_struct *p) p->prio >= current->prio) return; + pc = preempt_count(); disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); if (unlikely(disabled != 1)) goto out; @@ -256,7 +263,7 @@ probe_wakeup(struct rq *rq, struct task_struct *p) wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu], - CALLER_ADDR1, CALLER_ADDR2, flags); + CALLER_ADDR1, CALLER_ADDR2, flags, pc); out_locked: __raw_spin_unlock(&wakeup_lock); -- cgit v1.1 From 77ae11f63befb7fc41ec256f1fcb72ca7e4160d5 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 2 Oct 2008 11:04:14 +0200 Subject: ring-buffer: fix build error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit fix: kernel/trace/ring_buffer.c: In function ‘rb_allocate_pages’: kernel/trace/ring_buffer.c:235: error: ‘cpu’ undeclared (first use in this function) kernel/trace/ring_buffer.c:235: error: (Each undeclared identifier is reported only once kernel/trace/ring_buffer.c:235: error: for each function it appears in.) Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9814571..54a3098 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -232,7 +232,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, for (i = 0; i < nr_pages; i++) { page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), - GFP_KERNEL, cpu_to_node(cpu)); + GFP_KERNEL, cpu_to_node(i)); if (!page) goto free_pages; list_add(&page->list, &pages); -- cgit v1.1 From cb5ab74204a6e2579d1119bf1348eb806526b12b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 2 Oct 2008 12:59:20 +0200 Subject: tracing/fastboot: change the printing of boot tracer according to bootgraph.pl Change the boot tracer printing to make it parsable for the scripts/bootgraph.pl script. We have now to output two lines for each initcall, according to the printk in do_one_initcall() in init/main.c We need now the call's time and the return's time. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index f2dac6f..7c15f3e 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -52,16 +52,24 @@ static enum print_line_t initcall_print_line(struct trace_iterator *iter) struct trace_boot *field = (struct trace_boot *)entry; struct boot_trace *it = &field->initcall; struct trace_seq *s = &iter->seq; + struct timespec calltime = ktime_to_timespec(it->calltime); + struct timespec rettime = ktime_to_timespec(it->rettime); if (entry->type == TRACE_BOOT) { - ret = trace_seq_printf(s, "%pF called from %i " - "returned %d after %lld msecs\n", - it->func, it->caller, it->result, - it->duration); - if (ret) - return TRACE_TYPE_HANDLED; - else + ret = trace_seq_printf(s, "[%5ld.%06ld] calling %pF @ %i\n", + calltime.tv_sec, + calltime.tv_nsec, + it->func, it->caller); + if (!ret) return TRACE_TYPE_PARTIAL_LINE; + ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %pF " + "returned %d after %lld msecs\n", + rettime.tv_sec, + rettime.tv_nsec, + it->func, it->result, it->duration); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; } return TRACE_TYPE_UNHANDLED; } -- cgit v1.1 From 5601020feb0c3010e9e3e0131e9697ac6a06777b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 2 Oct 2008 13:26:05 +0200 Subject: tracing/fastboot: get the initcall name before it disappears After some initcall traces, some initcall names may be inconsistent. That's because these functions will disappear from the .init section and also their name from the symbols table. So we have to copy the name of the function in a buffer large enough during the trace appending. It is not costly for the ring_buffer because the number of initcall entries is commonly not really large. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 7c15f3e..b9dc2c0 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "trace.h" @@ -56,17 +57,19 @@ static enum print_line_t initcall_print_line(struct trace_iterator *iter) struct timespec rettime = ktime_to_timespec(it->rettime); if (entry->type == TRACE_BOOT) { - ret = trace_seq_printf(s, "[%5ld.%06ld] calling %pF @ %i\n", + ret = trace_seq_printf(s, "[%5ld.%06ld] calling %s @ %i\n", calltime.tv_sec, calltime.tv_nsec, it->func, it->caller); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %pF " + + ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %s " "returned %d after %lld msecs\n", rettime.tv_sec, rettime.tv_nsec, it->func, it->result, it->duration); + if (!ret) return TRACE_TYPE_PARTIAL_LINE; return TRACE_TYPE_HANDLED; @@ -83,8 +86,7 @@ struct tracer boot_tracer __read_mostly = .print_line = initcall_print_line, }; - -void trace_boot(struct boot_trace *it) +void trace_boot(struct boot_trace *it, initcall_t fn) { struct ring_buffer_event *event; struct trace_boot *entry; @@ -95,6 +97,10 @@ void trace_boot(struct boot_trace *it) if (!trace_boot_enabled) return; + /* Get its name now since this function could + * disappear because it is in the .init section. + */ + sprint_symbol(it->func, (unsigned long)fn); preempt_disable(); data = tr->data[smp_processor_id()]; -- cgit v1.1 From aa1e0e3bcf95ce684d005bedb16e5d4559455685 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 2 Oct 2008 19:18:09 -0400 Subject: ring_buffer: map to cpu not page My original patch had a compile bug when NUMA was configured. I referenced cpu when it should have been cpu_buffer->cpu. Ingo quickly fixed this bug by replacing cpu with 'i' because that was the loop counter. Unfortunately, the 'i' was the counter of pages, not CPUs. This caused a crash when the number of pages allocated for the buffers exceeded the number of pages, which would usually be the case. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 54a3098..6b8dac0 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -232,7 +232,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, for (i = 0; i < nr_pages; i++) { page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), - GFP_KERNEL, cpu_to_node(i)); + GFP_KERNEL, cpu_to_node(cpu_buffer->cpu)); if (!page) goto free_pages; list_add(&page->list, &pages); -- cgit v1.1 From 6450c1d3213e27b0dcbf34cce7ad1ae74244c520 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 2 Oct 2008 19:23:04 -0400 Subject: ftrace: move pc counter in irqtrace The assigning of the pc counter is in the wrong spot in the check_critical_timing function. The pc variable is used in the out jump. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_irqsoff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index f925dbbf..a7db7f0 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -142,11 +142,11 @@ check_critical_timing(struct trace_array *tr, local_save_flags(flags); + pc = preempt_count(); + if (!report_latency(delta)) goto out; - pc = preempt_count(); - spin_lock_irqsave(&max_trace_lock, flags); /* check if we are still the max latency */ -- cgit v1.1 From 097d036a2f25eecc42435c57e010aaf4a2eed2d9 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 3 Oct 2008 15:39:21 +0200 Subject: tracing/fastboot: only trace non-module initcalls At this time, only built-in initcalls interest us. We can't really produce a relevant graph if we include the modules initcall too. I had good results after this patch (see svg in attachment). Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index b9dc2c0..a7efe35 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -22,11 +22,16 @@ void start_boot_trace(void) trace_boot_enabled = 1; } -void stop_boot_trace(struct trace_array *tr) +void stop_boot_trace(void) { trace_boot_enabled = 0; } +void reset_boot_trace(struct trace_array *tr) +{ + stop_boot_trace(); +} + static void boot_trace_init(struct trace_array *tr) { int cpu; @@ -43,7 +48,7 @@ static void boot_trace_ctrl_update(struct trace_array *tr) if (tr->ctrl) start_boot_trace(); else - stop_boot_trace(tr); + stop_boot_trace(); } static enum print_line_t initcall_print_line(struct trace_iterator *iter) @@ -81,7 +86,7 @@ struct tracer boot_tracer __read_mostly = { .name = "initcall", .init = boot_trace_init, - .reset = stop_boot_trace, + .reset = reset_boot_trace, .ctrl_update = boot_trace_ctrl_update, .print_line = initcall_print_line, }; -- cgit v1.1 From 6f807acd27734197b11d42829d3cbb9c0937b572 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 4 Oct 2008 02:00:58 -0400 Subject: ring-buffer: move page indexes into page headers Remove the global head and tail indexes and move them into the page header. Each page will now keep track of where the last write and read was made. We also rename the head and tail to read and write for better clarification. This patch is needed for future enhancements to move the ring buffer to a lockless solution. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 75 +++++++++++++++++++++++++--------------------- 1 file changed, 41 insertions(+), 34 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6b8dac0..09d4f0d 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -117,6 +117,8 @@ void *ring_buffer_event_data(struct ring_buffer_event *event) struct buffer_page { u64 time_stamp; /* page time stamp */ unsigned size; /* size of page data */ + unsigned write; /* index for next write */ + unsigned read; /* index for next read */ struct list_head list; /* list of free pages */ void *page; /* Actual data page */ }; @@ -153,11 +155,8 @@ struct ring_buffer_per_cpu { spinlock_t lock; struct lock_class_key lock_key; struct list_head pages; - unsigned long head; /* read from head */ - unsigned long tail; /* write to tail */ - unsigned long reader; - struct buffer_page *head_page; - struct buffer_page *tail_page; + struct buffer_page *head_page; /* read from head */ + struct buffer_page *tail_page; /* write to tail */ struct buffer_page *reader_page; unsigned long overrun; unsigned long entries; @@ -566,10 +565,11 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) { - return (cpu_buffer->reader == cpu_buffer->reader_page->size && + return cpu_buffer->reader_page->read == cpu_buffer->reader_page->size && (cpu_buffer->tail_page == cpu_buffer->reader_page || (cpu_buffer->tail_page == cpu_buffer->head_page && - cpu_buffer->head == cpu_buffer->tail))); + cpu_buffer->head_page->read == + cpu_buffer->tail_page->write)); } static inline int rb_null_event(struct ring_buffer_event *event) @@ -577,7 +577,7 @@ static inline int rb_null_event(struct ring_buffer_event *event) return event->type == RINGBUF_TYPE_PADDING; } -static inline void *rb_page_index(struct buffer_page *page, unsigned index) +static inline void *__rb_page_index(struct buffer_page *page, unsigned index) { return page->page + index; } @@ -585,15 +585,21 @@ static inline void *rb_page_index(struct buffer_page *page, unsigned index) static inline struct ring_buffer_event * rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer) { - return rb_page_index(cpu_buffer->reader_page, - cpu_buffer->reader); + return __rb_page_index(cpu_buffer->reader_page, + cpu_buffer->reader_page->read); +} + +static inline struct ring_buffer_event * +rb_head_event(struct ring_buffer_per_cpu *cpu_buffer) +{ + return __rb_page_index(cpu_buffer->head_page, + cpu_buffer->head_page->read); } static inline struct ring_buffer_event * rb_iter_head_event(struct ring_buffer_iter *iter) { - return rb_page_index(iter->head_page, - iter->head); + return __rb_page_index(iter->head_page, iter->head); } /* @@ -610,7 +616,7 @@ static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer) for (head = 0; head < rb_head_size(cpu_buffer); head += rb_event_length(event)) { - event = rb_page_index(cpu_buffer->head_page, head); + event = __rb_page_index(cpu_buffer->head_page, head); BUG_ON(rb_null_event(event)); /* Only count data entries */ if (event->type != RINGBUF_TYPE_DATA) @@ -640,13 +646,13 @@ rb_add_stamp(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) static void rb_reset_head_page(struct ring_buffer_per_cpu *cpu_buffer) { - cpu_buffer->head = 0; + cpu_buffer->head_page->read = 0; } static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp; - cpu_buffer->reader = 0; + cpu_buffer->reader_page->read = 0; } static inline void rb_inc_iter(struct ring_buffer_iter *iter) @@ -743,9 +749,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer *buffer = cpu_buffer->buffer; struct ring_buffer_event *event; - /* No locking needed for tail page */ tail_page = cpu_buffer->tail_page; - tail = cpu_buffer->tail; + tail = cpu_buffer->tail_page->write; if (tail + length > BUF_PAGE_SIZE) { struct buffer_page *next_page = tail_page; @@ -774,7 +779,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, } if (tail != BUF_PAGE_SIZE) { - event = rb_page_index(tail_page, tail); + event = __rb_page_index(tail_page, tail); /* page padding */ event->type = RINGBUF_TYPE_PADDING; } @@ -784,14 +789,14 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, tail_page->size = 0; tail = 0; cpu_buffer->tail_page = tail_page; - cpu_buffer->tail = tail; + cpu_buffer->tail_page->write = tail; rb_add_stamp(cpu_buffer, ts); spin_unlock(&cpu_buffer->lock); } BUG_ON(tail + length > BUF_PAGE_SIZE); - event = rb_page_index(tail_page, tail); + event = __rb_page_index(tail_page, tail); rb_update_event(event, type, length); return event; @@ -823,12 +828,12 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, return -1; /* check to see if we went to the next page */ - if (cpu_buffer->tail) { + if (cpu_buffer->tail_page->write) { /* Still on same page, update timestamp */ event->time_delta = *delta & TS_MASK; event->array[0] = *delta >> TS_SHIFT; /* commit the time event */ - cpu_buffer->tail += + cpu_buffer->tail_page->write += rb_event_length(event); cpu_buffer->write_stamp = *ts; *delta = 0; @@ -846,7 +851,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, ts = ring_buffer_time_stamp(cpu_buffer->cpu); - if (cpu_buffer->tail) { + if (cpu_buffer->tail_page->write) { delta = ts - cpu_buffer->write_stamp; if (test_time_stamp(delta)) { @@ -868,7 +873,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, return NULL; /* If the reserve went to the next page, our delta is zero */ - if (!cpu_buffer->tail) + if (!cpu_buffer->tail_page->write) delta = 0; event->time_delta = delta; @@ -933,8 +938,8 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event) { - cpu_buffer->tail += rb_event_length(event); - cpu_buffer->tail_page->size = cpu_buffer->tail; + cpu_buffer->tail_page->write += rb_event_length(event); + cpu_buffer->tail_page->size = cpu_buffer->tail_page->write; cpu_buffer->write_stamp += event->time_delta; cpu_buffer->entries++; } @@ -1178,10 +1183,10 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter) /* Iterator usage is expected to have record disabled */ if (list_empty(&cpu_buffer->reader_page->list)) { iter->head_page = cpu_buffer->head_page; - iter->head = cpu_buffer->head; + iter->head = cpu_buffer->head_page->read; } else { iter->head_page = cpu_buffer->reader_page; - iter->head = cpu_buffer->reader; + iter->head = cpu_buffer->reader_page->read; } if (iter->head) iter->read_stamp = cpu_buffer->read_stamp; @@ -1200,7 +1205,7 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter) cpu_buffer = iter->cpu_buffer; return iter->head_page == cpu_buffer->tail_page && - iter->head == cpu_buffer->tail; + iter->head == cpu_buffer->tail_page->write; } static void @@ -1277,11 +1282,11 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) reader = cpu_buffer->reader_page; /* If there's more to read, return this page */ - if (cpu_buffer->reader < reader->size) + if (cpu_buffer->reader_page->read < reader->size) goto out; /* Never should we have an index greater than the size */ - WARN_ON(cpu_buffer->reader > reader->size); + WARN_ON(cpu_buffer->reader_page->read > reader->size); /* check if we caught up to the tail */ reader = NULL; @@ -1342,7 +1347,7 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer) rb_update_read_stamp(cpu_buffer, event); length = rb_event_length(event); - cpu_buffer->reader += length; + cpu_buffer->reader_page->read += length; } static void rb_advance_iter(struct ring_buffer_iter *iter) @@ -1373,7 +1378,7 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) * at the tail of the buffer. */ BUG_ON((iter->head_page == cpu_buffer->tail_page) && - (iter->head + length > cpu_buffer->tail)); + (iter->head + length > cpu_buffer->tail_page->write)); rb_update_iter_read_stamp(iter, event); @@ -1623,7 +1628,9 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) INIT_LIST_HEAD(&cpu_buffer->reader_page->list); cpu_buffer->reader_page->size = 0; - cpu_buffer->head = cpu_buffer->tail = cpu_buffer->reader = 0; + cpu_buffer->head_page->read = 0; + cpu_buffer->tail_page->write = 0; + cpu_buffer->reader_page->read = 0; cpu_buffer->overrun = 0; cpu_buffer->entries = 0; -- cgit v1.1 From bf41a158cacba6ca5fc6407a54e7ad8ce1567e2e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 4 Oct 2008 02:00:59 -0400 Subject: ring-buffer: make reentrant This patch replaces the local_irq_save/restore with preempt_disable/ enable. This allows for interrupts to enter while recording. To write to the ring buffer, you must reserve data, and then commit it. During this time, an interrupt may call a trace function that will also record into the buffer before the commit is made. The interrupt will reserve its entry after the first entry, even though the first entry did not finish yet. The time stamp delta of the interrupt entry will be zero, since in the view of the trace, the interrupt happened during the first field anyway. Locking still takes place when the tail/write moves from one page to the next. The reader always takes the locks. A new page pointer is added, called the commit. The write/tail will always point to the end of all entries. The commit field will point to the last committed entry. Only this commit entry may update the write time stamp. The reader can only go up to the commit. It cannot go past it. If a lot of interrupts come in during a commit that fills up the buffer, and it happens to make it all the way around the buffer back to the commit, then a warning is printed and new events will be dropped. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 487 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 374 insertions(+), 113 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 09d4f0d..94af1fe 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -116,8 +116,8 @@ void *ring_buffer_event_data(struct ring_buffer_event *event) */ struct buffer_page { u64 time_stamp; /* page time stamp */ - unsigned size; /* size of page data */ - unsigned write; /* index for next write */ + local_t write; /* index for next write */ + local_t commit; /* write commited index */ unsigned read; /* index for next read */ struct list_head list; /* list of free pages */ void *page; /* Actual data page */ @@ -157,6 +157,7 @@ struct ring_buffer_per_cpu { struct list_head pages; struct buffer_page *head_page; /* read from head */ struct buffer_page *tail_page; /* write to tail */ + struct buffer_page *commit_page; /* commited pages */ struct buffer_page *reader_page; unsigned long overrun; unsigned long entries; @@ -185,12 +186,32 @@ struct ring_buffer_iter { u64 read_stamp; }; -#define RB_WARN_ON(buffer, cond) \ - if (unlikely(cond)) { \ - atomic_inc(&buffer->record_disabled); \ - WARN_ON(1); \ - return -1; \ - } +#define RB_WARN_ON(buffer, cond) \ + do { \ + if (unlikely(cond)) { \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + } \ + } while (0) + +#define RB_WARN_ON_RET(buffer, cond) \ + do { \ + if (unlikely(cond)) { \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + return -1; \ + } \ + } while (0) + +#define RB_WARN_ON_ONCE(buffer, cond) \ + do { \ + static int once; \ + if (unlikely(cond) && !once) { \ + once++; \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + } \ + } while (0) /** * check_pages - integrity check of buffer pages @@ -204,22 +225,19 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) struct list_head *head = &cpu_buffer->pages; struct buffer_page *page, *tmp; - RB_WARN_ON(cpu_buffer, head->next->prev != head); - RB_WARN_ON(cpu_buffer, head->prev->next != head); + RB_WARN_ON_RET(cpu_buffer, head->next->prev != head); + RB_WARN_ON_RET(cpu_buffer, head->prev->next != head); list_for_each_entry_safe(page, tmp, head, list) { - RB_WARN_ON(cpu_buffer, page->list.next->prev != &page->list); - RB_WARN_ON(cpu_buffer, page->list.prev->next != &page->list); + RB_WARN_ON_RET(cpu_buffer, + page->list.next->prev != &page->list); + RB_WARN_ON_RET(cpu_buffer, + page->list.prev->next != &page->list); } return 0; } -static unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer) -{ - return cpu_buffer->head_page->size; -} - static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) { @@ -286,7 +304,6 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) page->page = (void *)addr; INIT_LIST_HEAD(&cpu_buffer->reader_page->list); - cpu_buffer->reader_page->size = 0; ret = rb_allocate_pages(cpu_buffer, buffer->pages); if (ret < 0) @@ -294,8 +311,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) cpu_buffer->head_page = list_entry(cpu_buffer->pages.next, struct buffer_page, list); - cpu_buffer->tail_page - = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page; return cpu_buffer; @@ -563,15 +579,6 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) return -ENOMEM; } -static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) -{ - return cpu_buffer->reader_page->read == cpu_buffer->reader_page->size && - (cpu_buffer->tail_page == cpu_buffer->reader_page || - (cpu_buffer->tail_page == cpu_buffer->head_page && - cpu_buffer->head_page->read == - cpu_buffer->tail_page->write)); -} - static inline int rb_null_event(struct ring_buffer_event *event) { return event->type == RINGBUF_TYPE_PADDING; @@ -602,6 +609,33 @@ rb_iter_head_event(struct ring_buffer_iter *iter) return __rb_page_index(iter->head_page, iter->head); } +static inline unsigned rb_page_write(struct buffer_page *bpage) +{ + return local_read(&bpage->write); +} + +static inline unsigned rb_page_commit(struct buffer_page *bpage) +{ + return local_read(&bpage->commit); +} + +/* Size is determined by what has been commited */ +static inline unsigned rb_page_size(struct buffer_page *bpage) +{ + return rb_page_commit(bpage); +} + +static inline unsigned +rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer) +{ + return rb_page_commit(cpu_buffer->commit_page); +} + +static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer) +{ + return rb_page_commit(cpu_buffer->head_page); +} + /* * When the tail hits the head and the buffer is in overwrite mode, * the head jumps to the next page and all content on the previous @@ -637,16 +671,76 @@ static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer, *page = list_entry(p, struct buffer_page, list); } -static inline void -rb_add_stamp(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) +static inline unsigned +rb_event_index(struct ring_buffer_event *event) { - cpu_buffer->tail_page->time_stamp = *ts; - cpu_buffer->write_stamp = *ts; + unsigned long addr = (unsigned long)event; + + return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); } -static void rb_reset_head_page(struct ring_buffer_per_cpu *cpu_buffer) +static inline int +rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) { - cpu_buffer->head_page->read = 0; + unsigned long addr = (unsigned long)event; + unsigned long index; + + index = rb_event_index(event); + addr &= PAGE_MASK; + + return cpu_buffer->commit_page->page == (void *)addr && + rb_commit_index(cpu_buffer) == index; +} + +static inline void +rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + unsigned long addr = (unsigned long)event; + unsigned long index; + + index = rb_event_index(event); + addr &= PAGE_MASK; + + while (cpu_buffer->commit_page->page != (void *)addr) { + RB_WARN_ON(cpu_buffer, + cpu_buffer->commit_page == cpu_buffer->tail_page); + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + rb_inc_page(cpu_buffer, &cpu_buffer->commit_page); + cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp; + } + + /* Now set the commit to the event's index */ + local_set(&cpu_buffer->commit_page->commit, index); +} + +static inline void +rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) +{ + /* + * We only race with interrupts and NMIs on this CPU. + * If we own the commit event, then we can commit + * all others that interrupted us, since the interruptions + * are in stack format (they finish before they come + * back to us). This allows us to do a simple loop to + * assign the commit to the tail. + */ + while (cpu_buffer->commit_page != cpu_buffer->tail_page) { + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + rb_inc_page(cpu_buffer, &cpu_buffer->commit_page); + cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp; + /* add barrier to keep gcc from optimizing too much */ + barrier(); + } + while (rb_commit_index(cpu_buffer) != + rb_page_write(cpu_buffer->commit_page)) { + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + barrier(); + } } static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer) @@ -745,61 +839,120 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, unsigned type, unsigned long length, u64 *ts) { struct buffer_page *tail_page, *head_page, *reader_page; - unsigned long tail; + unsigned long tail, write; struct ring_buffer *buffer = cpu_buffer->buffer; struct ring_buffer_event *event; + unsigned long flags; tail_page = cpu_buffer->tail_page; - tail = cpu_buffer->tail_page->write; + write = local_add_return(length, &tail_page->write); + tail = write - length; - if (tail + length > BUF_PAGE_SIZE) { + /* See if we shot pass the end of this buffer page */ + if (write > BUF_PAGE_SIZE) { struct buffer_page *next_page = tail_page; - spin_lock(&cpu_buffer->lock); + spin_lock_irqsave(&cpu_buffer->lock, flags); + rb_inc_page(cpu_buffer, &next_page); head_page = cpu_buffer->head_page; reader_page = cpu_buffer->reader_page; /* we grabbed the lock before incrementing */ - WARN_ON(next_page == reader_page); + RB_WARN_ON(cpu_buffer, next_page == reader_page); + + /* + * If for some reason, we had an interrupt storm that made + * it all the way around the buffer, bail, and warn + * about it. + */ + if (unlikely(next_page == cpu_buffer->commit_page)) { + WARN_ON_ONCE(1); + goto out_unlock; + } if (next_page == head_page) { if (!(buffer->flags & RB_FL_OVERWRITE)) { - spin_unlock(&cpu_buffer->lock); - return NULL; + /* reset write */ + if (tail <= BUF_PAGE_SIZE) + local_set(&tail_page->write, tail); + goto out_unlock; } - /* count overflows */ - rb_update_overflow(cpu_buffer); + /* tail_page has not moved yet? */ + if (tail_page == cpu_buffer->tail_page) { + /* count overflows */ + rb_update_overflow(cpu_buffer); + + rb_inc_page(cpu_buffer, &head_page); + cpu_buffer->head_page = head_page; + cpu_buffer->head_page->read = 0; + } + } - rb_inc_page(cpu_buffer, &head_page); - cpu_buffer->head_page = head_page; - rb_reset_head_page(cpu_buffer); + /* + * If the tail page is still the same as what we think + * it is, then it is up to us to update the tail + * pointer. + */ + if (tail_page == cpu_buffer->tail_page) { + local_set(&next_page->write, 0); + local_set(&next_page->commit, 0); + cpu_buffer->tail_page = next_page; + + /* reread the time stamp */ + *ts = ring_buffer_time_stamp(cpu_buffer->cpu); + cpu_buffer->tail_page->time_stamp = *ts; } - if (tail != BUF_PAGE_SIZE) { + /* + * The actual tail page has moved forward. + */ + if (tail < BUF_PAGE_SIZE) { + /* Mark the rest of the page with padding */ event = __rb_page_index(tail_page, tail); - /* page padding */ event->type = RINGBUF_TYPE_PADDING; } - tail_page->size = tail; - tail_page = next_page; - tail_page->size = 0; - tail = 0; - cpu_buffer->tail_page = tail_page; - cpu_buffer->tail_page->write = tail; - rb_add_stamp(cpu_buffer, ts); - spin_unlock(&cpu_buffer->lock); + if (tail <= BUF_PAGE_SIZE) + /* Set the write back to the previous setting */ + local_set(&tail_page->write, tail); + + /* + * If this was a commit entry that failed, + * increment that too + */ + if (tail_page == cpu_buffer->commit_page && + tail == rb_commit_index(cpu_buffer)) { + rb_set_commit_to_write(cpu_buffer); + } + + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + + /* fail and let the caller try again */ + return ERR_PTR(-EAGAIN); } - BUG_ON(tail + length > BUF_PAGE_SIZE); + /* We reserved something on the buffer */ + + BUG_ON(write > BUF_PAGE_SIZE); event = __rb_page_index(tail_page, tail); rb_update_event(event, type, length); + /* + * If this is a commit and the tail is zero, then update + * this page's time stamp. + */ + if (!tail && rb_is_commit(cpu_buffer, event)) + cpu_buffer->commit_page->time_stamp = *ts; + return event; + + out_unlock: + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + return NULL; } static int @@ -808,6 +961,7 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, { struct ring_buffer_event *event; static int once; + int ret; if (unlikely(*delta > (1ULL << 59) && !once++)) { printk(KERN_WARNING "Delta way too big! %llu" @@ -825,21 +979,38 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, RB_LEN_TIME_EXTEND, ts); if (!event) - return -1; + return -EBUSY; - /* check to see if we went to the next page */ - if (cpu_buffer->tail_page->write) { - /* Still on same page, update timestamp */ - event->time_delta = *delta & TS_MASK; - event->array[0] = *delta >> TS_SHIFT; - /* commit the time event */ - cpu_buffer->tail_page->write += - rb_event_length(event); + if (PTR_ERR(event) == -EAGAIN) + return -EAGAIN; + + /* Only a commited time event can update the write stamp */ + if (rb_is_commit(cpu_buffer, event)) { + /* + * If this is the first on the page, then we need to + * update the page itself, and just put in a zero. + */ + if (rb_event_index(event)) { + event->time_delta = *delta & TS_MASK; + event->array[0] = *delta >> TS_SHIFT; + } else { + cpu_buffer->commit_page->time_stamp = *ts; + event->time_delta = 0; + event->array[0] = 0; + } cpu_buffer->write_stamp = *ts; - *delta = 0; + /* let the caller know this was the commit */ + ret = 1; + } else { + /* Darn, this is just wasted space */ + event->time_delta = 0; + event->array[0] = 0; + ret = 0; } - return 0; + *delta = 0; + + return ret; } static struct ring_buffer_event * @@ -848,32 +1019,69 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, { struct ring_buffer_event *event; u64 ts, delta; + int commit = 0; + again: ts = ring_buffer_time_stamp(cpu_buffer->cpu); - if (cpu_buffer->tail_page->write) { + /* + * Only the first commit can update the timestamp. + * Yes there is a race here. If an interrupt comes in + * just after the conditional and it traces too, then it + * will also check the deltas. More than one timestamp may + * also be made. But only the entry that did the actual + * commit will be something other than zero. + */ + if (cpu_buffer->tail_page == cpu_buffer->commit_page && + rb_page_write(cpu_buffer->tail_page) == + rb_commit_index(cpu_buffer)) { + delta = ts - cpu_buffer->write_stamp; + /* make sure this delta is calculated here */ + barrier(); + + /* Did the write stamp get updated already? */ + if (unlikely(ts < cpu_buffer->write_stamp)) + goto again; + if (test_time_stamp(delta)) { - int ret; - ret = rb_add_time_stamp(cpu_buffer, &ts, &delta); - if (ret < 0) + commit = rb_add_time_stamp(cpu_buffer, &ts, &delta); + + if (commit == -EBUSY) return NULL; + + if (commit == -EAGAIN) + goto again; + + RB_WARN_ON(cpu_buffer, commit < 0); } - } else { - spin_lock(&cpu_buffer->lock); - rb_add_stamp(cpu_buffer, &ts); - spin_unlock(&cpu_buffer->lock); + } else + /* Non commits have zero deltas */ delta = 0; - } event = __rb_reserve_next(cpu_buffer, type, length, &ts); - if (!event) + if (PTR_ERR(event) == -EAGAIN) + goto again; + + if (!event) { + if (unlikely(commit)) + /* + * Ouch! We needed a timestamp and it was commited. But + * we didn't get our event reserved. + */ + rb_set_commit_to_write(cpu_buffer); return NULL; + } - /* If the reserve went to the next page, our delta is zero */ - if (!cpu_buffer->tail_page->write) + /* + * If the timestamp was commited, make the commit our entry + * now so that we will update it when needed. + */ + if (commit) + rb_set_commit_event(cpu_buffer, event); + else if (!rb_is_commit(cpu_buffer, event)) delta = 0; event->time_delta = delta; @@ -881,6 +1089,8 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, return event; } +static DEFINE_PER_CPU(int, rb_need_resched); + /** * ring_buffer_lock_reserve - reserve a part of the buffer * @buffer: the ring buffer to reserve from @@ -904,12 +1114,15 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; - int cpu; + int cpu, resched; if (atomic_read(&buffer->record_disabled)) return NULL; - local_irq_save(*flags); + /* If we are tracing schedule, we don't want to recurse */ + resched = need_resched(); + preempt_disable_notrace(); + cpu = raw_smp_processor_id(); if (!cpu_isset(cpu, buffer->cpumask)) @@ -922,26 +1135,42 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, length = rb_calculate_event_length(length); if (length > BUF_PAGE_SIZE) - return NULL; + goto out; event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length); if (!event) goto out; + /* + * Need to store resched state on this cpu. + * Only the first needs to. + */ + + if (preempt_count() == 1) + per_cpu(rb_need_resched, cpu) = resched; + return event; out: - local_irq_restore(*flags); + if (resched) + preempt_enable_notrace(); + else + preempt_enable_notrace(); return NULL; } static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event) { - cpu_buffer->tail_page->write += rb_event_length(event); - cpu_buffer->tail_page->size = cpu_buffer->tail_page->write; - cpu_buffer->write_stamp += event->time_delta; cpu_buffer->entries++; + + /* Only process further if we own the commit */ + if (!rb_is_commit(cpu_buffer, event)) + return; + + cpu_buffer->write_stamp += event->time_delta; + + rb_set_commit_to_write(cpu_buffer); } /** @@ -965,7 +1194,16 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer, rb_commit(cpu_buffer, event); - local_irq_restore(flags); + /* + * Only the last preempt count needs to restore preemption. + */ + if (preempt_count() == 1) { + if (per_cpu(rb_need_resched, cpu)) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); + } else + preempt_enable_no_resched_notrace(); return 0; } @@ -989,15 +1227,17 @@ int ring_buffer_write(struct ring_buffer *buffer, { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; - unsigned long event_length, flags; + unsigned long event_length; void *body; int ret = -EBUSY; - int cpu; + int cpu, resched; if (atomic_read(&buffer->record_disabled)) return -EBUSY; - local_irq_save(flags); + resched = need_resched(); + preempt_disable_notrace(); + cpu = raw_smp_processor_id(); if (!cpu_isset(cpu, buffer->cpumask)) @@ -1022,11 +1262,26 @@ int ring_buffer_write(struct ring_buffer *buffer, ret = 0; out: - local_irq_restore(flags); + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); return ret; } +static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct buffer_page *reader = cpu_buffer->reader_page; + struct buffer_page *head = cpu_buffer->head_page; + struct buffer_page *commit = cpu_buffer->commit_page; + + return reader->read == rb_page_commit(reader) && + (commit == reader || + (commit == head && + head->read == rb_page_commit(commit))); +} + /** * ring_buffer_record_disable - stop all writes into the buffer * @buffer: The ring buffer to stop writes to. @@ -1204,8 +1459,8 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter) cpu_buffer = iter->cpu_buffer; - return iter->head_page == cpu_buffer->tail_page && - iter->head == cpu_buffer->tail_page->write; + return iter->head_page == cpu_buffer->commit_page && + iter->head == rb_commit_index(cpu_buffer); } static void @@ -1282,15 +1537,16 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) reader = cpu_buffer->reader_page; /* If there's more to read, return this page */ - if (cpu_buffer->reader_page->read < reader->size) + if (cpu_buffer->reader_page->read < rb_page_size(reader)) goto out; /* Never should we have an index greater than the size */ - WARN_ON(cpu_buffer->reader_page->read > reader->size); + RB_WARN_ON(cpu_buffer, + cpu_buffer->reader_page->read > rb_page_size(reader)); /* check if we caught up to the tail */ reader = NULL; - if (cpu_buffer->tail_page == cpu_buffer->reader_page) + if (cpu_buffer->commit_page == cpu_buffer->reader_page) goto out; /* @@ -1301,7 +1557,9 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) reader = cpu_buffer->head_page; cpu_buffer->reader_page->list.next = reader->list.next; cpu_buffer->reader_page->list.prev = reader->list.prev; - cpu_buffer->reader_page->size = 0; + + local_set(&cpu_buffer->reader_page->write, 0); + local_set(&cpu_buffer->reader_page->commit, 0); /* Make the reader page now replace the head */ reader->list.prev->next = &cpu_buffer->reader_page->list; @@ -1313,7 +1571,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) */ cpu_buffer->head_page = cpu_buffer->reader_page; - if (cpu_buffer->tail_page != reader) + if (cpu_buffer->commit_page != reader) rb_inc_page(cpu_buffer, &cpu_buffer->head_page); /* Finally update the reader page to the new head */ @@ -1363,8 +1621,8 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) /* * Check if we are at the end of the buffer. */ - if (iter->head >= iter->head_page->size) { - BUG_ON(iter->head_page == cpu_buffer->tail_page); + if (iter->head >= rb_page_size(iter->head_page)) { + BUG_ON(iter->head_page == cpu_buffer->commit_page); rb_inc_iter(iter); return; } @@ -1377,16 +1635,16 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) * This should not be called to advance the header if we are * at the tail of the buffer. */ - BUG_ON((iter->head_page == cpu_buffer->tail_page) && - (iter->head + length > cpu_buffer->tail_page->write)); + BUG_ON((iter->head_page == cpu_buffer->commit_page) && + (iter->head + length > rb_commit_index(cpu_buffer))); rb_update_iter_read_stamp(iter, event); iter->head += length; /* check for end of page padding */ - if ((iter->head >= iter->head_page->size) && - (iter->head_page != cpu_buffer->tail_page)) + if ((iter->head >= rb_page_size(iter->head_page)) && + (iter->head_page != cpu_buffer->commit_page)) rb_advance_iter(iter); } @@ -1420,7 +1678,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) switch (event->type) { case RINGBUF_TYPE_PADDING: - WARN_ON(1); + RB_WARN_ON(cpu_buffer, 1); rb_advance_reader(cpu_buffer); return NULL; @@ -1622,14 +1880,17 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) { cpu_buffer->head_page = list_entry(cpu_buffer->pages.next, struct buffer_page, list); - cpu_buffer->head_page->size = 0; - cpu_buffer->tail_page = cpu_buffer->head_page; - cpu_buffer->tail_page->size = 0; - INIT_LIST_HEAD(&cpu_buffer->reader_page->list); - cpu_buffer->reader_page->size = 0; + local_set(&cpu_buffer->head_page->write, 0); + local_set(&cpu_buffer->head_page->commit, 0); cpu_buffer->head_page->read = 0; - cpu_buffer->tail_page->write = 0; + + cpu_buffer->tail_page = cpu_buffer->head_page; + cpu_buffer->commit_page = cpu_buffer->head_page; + + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + local_set(&cpu_buffer->reader_page->write, 0); + local_set(&cpu_buffer->reader_page->commit, 0); cpu_buffer->reader_page->read = 0; cpu_buffer->overrun = 0; -- cgit v1.1 From 3ea2e6d71aafe35b8aaf89ed711a283815acfae6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 4 Oct 2008 02:01:00 -0400 Subject: ftrace: make some tracers reentrant Now that the ring buffer is reentrant, some of the ftrace tracers (sched_swich, debugging traces) can also be reentrant. Note: Never make the function tracer reentrant, that can cause recursion problems all over the kernel. The function tracer must disable reentrancy. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 10 ++-------- kernel/trace/trace_sched_switch.c | 10 ++-------- 2 files changed, 4 insertions(+), 16 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1cd2e81..caa4051 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -839,7 +839,6 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; - long disabled; int cpu; int pc; @@ -850,12 +849,10 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) preempt_disable_notrace(); cpu = raw_smp_processor_id(); data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) + if (likely(!atomic_read(&data->disabled))) ftrace_trace_special(tr, data, arg1, arg2, arg3, pc); - atomic_dec(&data->disabled); preempt_enable_notrace(); } @@ -2961,7 +2958,6 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) struct trace_array_cpu *data; struct print_entry *entry; unsigned long flags, irq_flags; - long disabled; int cpu, len = 0, size, pc; if (!tr->ctrl || tracing_disabled) @@ -2971,9 +2967,8 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) preempt_disable_notrace(); cpu = raw_smp_processor_id(); data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (unlikely(disabled != 1)) + if (unlikely(atomic_read(&data->disabled))) goto out; spin_lock_irqsave(&trace_buf_lock, flags); @@ -2999,7 +2994,6 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) spin_unlock_irqrestore(&trace_buf_lock, flags); out: - atomic_dec(&data->disabled); preempt_enable_notrace(); return len; diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index c7fa08a..b8f56be 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -24,7 +24,6 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, { struct trace_array_cpu *data; unsigned long flags; - long disabled; int cpu; int pc; @@ -41,12 +40,10 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, local_irq_save(flags); cpu = raw_smp_processor_id(); data = ctx_trace->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) + if (likely(!atomic_read(&data->disabled))) tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } @@ -55,7 +52,6 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) { struct trace_array_cpu *data; unsigned long flags; - long disabled; int cpu, pc; if (!likely(tracer_enabled)) @@ -67,13 +63,11 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) local_irq_save(flags); cpu = raw_smp_processor_id(); data = ctx_trace->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) + if (likely(!atomic_read(&data->disabled))) tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } -- cgit v1.1 From c2931e05ec5965597cbfb79ad332d4a29aeceb23 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 4 Oct 2008 22:04:44 +0200 Subject: ftrace: return an error when setting a nonexistent tracer When one try to set a nonexistent tracer, no error is returned as if the name of the tracer was correct. We should return -EINVAL. Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index caa4051..78d5661 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2381,9 +2381,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, struct tracer *t; char buf[max_tracer_type_len+1]; int i; + size_t ret; if (cnt > max_tracer_type_len) cnt = max_tracer_type_len; + ret = cnt; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; @@ -2399,7 +2401,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, if (strcmp(t->name, buf) == 0) break; } - if (!t || t == current_trace) + if (!t) { + ret = -EINVAL; + goto out; + } + if (t == current_trace) goto out; if (current_trace && current_trace->reset) @@ -2412,9 +2418,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&trace_types_lock); - filp->f_pos += cnt; + if (ret == cnt) + filp->f_pos += cnt; - return cnt; + return ret; } static ssize_t -- cgit v1.1 From 8a5d900cca57115326bc5b9e7f3bac980986c2c8 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sat, 4 Oct 2008 13:42:27 -0700 Subject: tracing/fastboot: fix printk format typo in boot tracer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When printing nanoseconds, the right printk format string is %09 not %06... Signed-off-by: Arjan van de Ven Acked-by: Frédéric Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace_boot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index a7efe35..d0a5e50 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -62,14 +62,14 @@ static enum print_line_t initcall_print_line(struct trace_iterator *iter) struct timespec rettime = ktime_to_timespec(it->rettime); if (entry->type == TRACE_BOOT) { - ret = trace_seq_printf(s, "[%5ld.%06ld] calling %s @ %i\n", + ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", calltime.tv_sec, calltime.tv_nsec, it->func, it->caller); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %s " + ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " "returned %d after %lld msecs\n", rettime.tv_sec, rettime.tv_nsec, -- cgit v1.1 From 2fbc474901933c8f0c09b0280dfbb6780cb8bd60 Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Wed, 8 Oct 2008 16:51:49 -0700 Subject: ftrace: fix hex output mode of ftrace Fix the output of ftrace in hex mode as the hi/lo nibbles are output in reverse order. Without this patch, the output of ftrace is: raw mode : 6474 0 141531612444 0 140 + 6402 120 S hex mode : 000091a4 00000000 000000023f1f50c1 00000000 c8 000000b2 00009120 87 ffff00c8 00000035 There is an inversion on ouput hex(6474) is 194a [based on a patch by Philippe Reynes ] Signed-off-by: Harvey Harrison Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 78d5661..36cbb87 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -336,14 +336,12 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len) } #define HEX_CHARS 17 -static const char hex2asc[] = "0123456789abcdef"; static int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) { unsigned char hex[HEX_CHARS]; unsigned char *data = mem; - unsigned char byte; int i, j; BUG_ON(len >= HEX_CHARS); @@ -353,10 +351,8 @@ trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) #else for (i = len-1, j = 0; i >= 0; i--) { #endif - byte = data[i]; - - hex[j++] = hex2asc[byte & 0x0f]; - hex[j++] = hex2asc[byte >> 4]; + hex[j++] = hex_asc_hi(data[i]); + hex[j++] = hex_asc_lo(data[i]); } hex[j++] = ' '; -- cgit v1.1 From ad0a3b68114e8f3c25ac0045b45a2838f23e3b3a Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Wed, 8 Oct 2008 17:44:55 -0700 Subject: trace: add build-time check to avoid overrunning hex buffer Remove the runtime BUG_ON and change to a compile-time check in the macro that calls the hex format routine [Noticed by Joe Perches] Signed-off-by: Harvey Harrison Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 36cbb87..d345d64 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -335,7 +335,8 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len) return len; } -#define HEX_CHARS 17 +#define MAX_MEMHEX_BYTES 8 +#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1) static int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) @@ -344,8 +345,6 @@ trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) unsigned char *data = mem; int i, j; - BUG_ON(len >= HEX_CHARS); - #ifdef __BIG_ENDIAN for (i = 0, j = 0; i < len; i++) { #else @@ -1668,6 +1667,7 @@ do { \ #define SEQ_PUT_HEX_FIELD_RET(s, x) \ do { \ + BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \ if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \ return 0; \ } while (0) -- cgit v1.1 From 4519d9e54dcd273975ad0adebad2a08c20428029 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 14 Oct 2008 14:15:43 +0200 Subject: tracing/stacktrace: improve help text Improve the help text that is displayed for CONFIG_STACK_TRACER. Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 396aea1..11fd03a 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -141,8 +141,17 @@ config STACK_TRACER select FTRACE select STACKTRACE help - This tracer records the max stack of the kernel, and displays - it in debugfs/tracing/stack_trace + This special tracer records the maximum stack footprint of the + kernel and displays it in debugfs/tracing/stack_trace. + + This tracer works by hooking into every function call that the + kernel executes, and keeping a maximum stack depth value and + stack-trace saved. Because this logic has to execute in every + kernel function, all the time, this option can slow down the + kernel measurably and is generally intended for kernel + developers only. + + Say N if unsure. config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" -- cgit v1.1 From 98d9c66ab07471006fd7910cb16453581c41a3e7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 14 Oct 2008 14:27:20 +0200 Subject: tracing/fastboot: improve help text Improve the help text of the boot tracer. Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 11fd03a..1cb3e1f 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -127,12 +127,17 @@ config BOOT_TRACER select TRACING help This tracer helps developers to optimize boot times: it records - the timings of the initcalls. Its aim is to be parsed by the - /scripts/bootgraph.pl tool to produce pretty graphics about - boot inefficiencies, giving a visual representation of the - delays during initcalls. Note that tracers self tests can't - be enabled if this tracer is selected since only one tracer - should touch the tracing buffer at a time. + the timings of the initcalls and traces key events and the identity + of tasks that can cause boot delays, such as context-switches. + + Its aim is to be parsed by the /scripts/bootgraph.pl tool to + produce pretty graphics about boot inefficiencies, giving a visual + representation of the delays during initcalls - but the raw + /debug/tracing/trace text output is readable too. + + ( Note that tracing self tests can't be enabled if this tracer is + selected, because the self-tests are an initcall as well and that + would invalidate the boot trace. ) config STACK_TRACER bool "Trace max stack" -- cgit v1.1 From 8cd162ce230b154e564a1285bb5f89fcf73f0dce Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 15 Oct 2008 20:37:23 +0200 Subject: sched: only update rq->clock while holding rq->lock Vatsa noticed rq->clock going funny and tracked it down to an update_rq_clock() outside a rq->lock section. This is a problem because things like double_rq_lock() update the rq->clock value for both rqs. Therefore disabling interrupts isn't strong enough. Reported-by: Srivatsa Vaddagiri Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 6f23059..c530b84 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4441,12 +4441,8 @@ need_resched_nonpreemptible: if (sched_feat(HRTICK)) hrtick_clear(rq); - /* - * Do the rq-clock update outside the rq lock: - */ - local_irq_disable(); + spin_lock_irq(&rq->lock); update_rq_clock(rq); - spin_lock(&rq->lock); clear_tsk_need_resched(prev); if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { -- cgit v1.1 From 85c0f90978bf50596dbd23854648020f1f9b5bfd Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:49:47 -0700 Subject: irq: introduce nr_irqs at this point nr_irqs is equal NR_IRQS convert a few easy users from NR_IRQS to dynamic nr_irqs. v2: according to Eric, we need to take care of arch without generic_hardirqs Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/autoprobe.c | 10 +++++----- kernel/irq/chip.c | 20 ++++++++++---------- kernel/irq/handle.c | 3 ++- kernel/irq/manage.c | 16 ++++++++-------- kernel/irq/proc.c | 2 +- kernel/irq/resend.c | 4 ++-- kernel/irq/spurious.c | 4 ++-- 7 files changed, 30 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index 533068c..c689e98 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -38,7 +38,7 @@ unsigned long probe_irq_on(void) * something may have generated an irq long ago and we want to * flush such a longstanding irq before considering it as spurious. */ - for (i = NR_IRQS-1; i > 0; i--) { + for (i = nr_irqs-1; i > 0; i--) { desc = irq_desc + i; spin_lock_irq(&desc->lock); @@ -68,7 +68,7 @@ unsigned long probe_irq_on(void) * (we must startup again here because if a longstanding irq * happened in the previous stage, it may have masked itself) */ - for (i = NR_IRQS-1; i > 0; i--) { + for (i = nr_irqs-1; i > 0; i--) { desc = irq_desc + i; spin_lock_irq(&desc->lock); @@ -89,7 +89,7 @@ unsigned long probe_irq_on(void) * Now filter out any obviously spurious interrupts */ mask = 0; - for (i = 0; i < NR_IRQS; i++) { + for (i = 0; i < nr_irqs; i++) { unsigned int status; desc = irq_desc + i; @@ -130,7 +130,7 @@ unsigned int probe_irq_mask(unsigned long val) int i; mask = 0; - for (i = 0; i < NR_IRQS; i++) { + for (i = 0; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; unsigned int status; @@ -173,7 +173,7 @@ int probe_irq_off(unsigned long val) { int i, irq_found = 0, nr_irqs = 0; - for (i = 0; i < NR_IRQS; i++) { + for (i = 0; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; unsigned int status; diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 5203a59..bba66e0 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -27,7 +27,7 @@ void dynamic_irq_init(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; } @@ -60,7 +60,7 @@ void dynamic_irq_cleanup(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); return; } @@ -92,7 +92,7 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq); return -EINVAL; } @@ -121,7 +121,7 @@ int set_irq_type(unsigned int irq, unsigned int type) unsigned long flags; int ret = -ENXIO; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; } @@ -149,7 +149,7 @@ int set_irq_data(unsigned int irq, void *data) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); return -EINVAL; @@ -175,7 +175,7 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); return -EINVAL; @@ -201,7 +201,7 @@ int set_irq_chip_data(unsigned int irq, void *data) struct irq_desc *desc = irq_desc + irq; unsigned long flags; - if (irq >= NR_IRQS || !desc->chip) { + if (irq >= nr_irqs || !desc->chip) { printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); return -EINVAL; } @@ -545,7 +545,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to install type control for IRQ%d\n", irq); return; @@ -610,7 +610,7 @@ void __init set_irq_noprobe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq); return; @@ -628,7 +628,7 @@ void __init set_irq_probe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= NR_IRQS) { + if (irq >= nr_irqs) { printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq); return; diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index f4c8a03..e9d022c 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -47,6 +47,7 @@ handle_bad_irq(unsigned int irq, struct irq_desc *desc) * * Controller mappings for all interrupt sources: */ +int nr_irqs = NR_IRQS; struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { [0 ... NR_IRQS-1] = { .status = IRQ_DISABLED, @@ -265,7 +266,7 @@ void early_init_irq_lock_class(void) { int i; - for (i = 0; i < NR_IRQS; i++) + for (i = 0; i < nr_irqs; i++) lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class); } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index d363f32..d5a4333 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -34,7 +34,7 @@ void synchronize_irq(unsigned int irq) struct irq_desc *desc = irq_desc + irq; unsigned int status; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return; do { @@ -143,7 +143,7 @@ void disable_irq_nosync(unsigned int irq) struct irq_desc *desc = irq_desc + irq; unsigned long flags; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return; spin_lock_irqsave(&desc->lock, flags); @@ -171,7 +171,7 @@ void disable_irq(unsigned int irq) { struct irq_desc *desc = irq_desc + irq; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return; disable_irq_nosync(irq); @@ -214,7 +214,7 @@ void enable_irq(unsigned int irq) struct irq_desc *desc = irq_desc + irq; unsigned long flags; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return; spin_lock_irqsave(&desc->lock, flags); @@ -290,7 +290,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) { struct irqaction *action; - if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST) + if (irq >= nr_irqs || irq_desc[irq].status & IRQ_NOREQUEST) return 0; action = irq_desc[irq].action; @@ -356,7 +356,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) int shared = 0; int ret; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return -EINVAL; if (desc->chip == &no_irq_chip) @@ -515,7 +515,7 @@ void free_irq(unsigned int irq, void *dev_id) unsigned long flags; WARN_ON(in_interrupt()); - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return; desc = irq_desc + irq; @@ -630,7 +630,7 @@ int request_irq(unsigned int irq, irq_handler_t handler, */ if ((irqflags & IRQF_SHARED) && !dev_id) return -EINVAL; - if (irq >= NR_IRQS) + if (irq >= nr_irqs) return -EINVAL; if (irq_desc[irq].status & IRQ_NOREQUEST) return -EINVAL; diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index a09dd29..e5225a6 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -240,7 +240,7 @@ void init_irq_proc(void) /* * Create entries for all existing IRQs. */ - for (i = 0; i < NR_IRQS; i++) + for (i = 0; i < nr_irqs; i++) register_irq_proc(i); } diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index a804679..cba8aa5 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -33,8 +33,8 @@ static void resend_irqs(unsigned long arg) struct irq_desc *desc; int irq; - while (!bitmap_empty(irqs_resend, NR_IRQS)) { - irq = find_first_bit(irqs_resend, NR_IRQS); + while (!bitmap_empty(irqs_resend, nr_irqs)) { + irq = find_first_bit(irqs_resend, nr_irqs); clear_bit(irq, irqs_resend); desc = irq_desc + irq; local_irq_disable(); diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 19fe9d6..e26ca1e 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -91,7 +91,7 @@ static int misrouted_irq(int irq) int i; int ok = 0; - for (i = 1; i < NR_IRQS; i++) { + for (i = 1; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; if (i == irq) /* Already tried */ @@ -107,7 +107,7 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { int i; - for (i = 1; i < NR_IRQS; i++) { + for (i = 1; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; unsigned int status; -- cgit v1.1 From d60458b224d6b997a582a05cb8c4b9bed9e17a1d Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:00 -0700 Subject: irq: make irq_desc to use dyn_array Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index e9d022c..e94eeca 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -48,6 +48,36 @@ handle_bad_irq(unsigned int irq, struct irq_desc *desc) * Controller mappings for all interrupt sources: */ int nr_irqs = NR_IRQS; + +#ifdef CONFIG_HAVE_DYN_ARRAY +static struct irq_desc irq_desc_init __initdata = { + .status = IRQ_DISABLED, + .chip = &no_irq_chip, + .handle_irq = handle_bad_irq, + .depth = 1, + .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock), +#ifdef CONFIG_SMP + .affinity = CPU_MASK_ALL +#endif +}; + +static void __init init_work(void *data) +{ + struct dyn_array *da = data; + int i; + struct irq_desc *desc; + + desc = *da->name; + + for (i = 0; i < *da->nr; i++) + memcpy(&desc[i], &irq_desc_init, sizeof(struct irq_desc)); +} + +struct irq_desc *irq_desc; +DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); + +#else + struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { [0 ... NR_IRQS-1] = { .status = IRQ_DISABLED, @@ -60,6 +90,7 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { #endif } }; +#endif /* * What should we do if we get a hw irq event on an illegal vector? -- cgit v1.1 From fa42d10dd5e1ff373061c0526f272106512301f9 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 19 Aug 2008 20:50:30 -0700 Subject: irq: sparse irqs, export nr_irqs fix: Building modules, stage 2. MODPOST 458 modules ERROR: "nr_irqs" [drivers/serial/8250.ko] undefined! Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index e94eeca..6ce3bcc 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -48,6 +48,7 @@ handle_bad_irq(unsigned int irq, struct irq_desc *desc) * Controller mappings for all interrupt sources: */ int nr_irqs = NR_IRQS; +EXPORT_SYMBOL_GPL(nr_irqs); #ifdef CONFIG_HAVE_DYN_ARRAY static struct irq_desc irq_desc_init __initdata = { -- cgit v1.1 From d17a55ded3393ad3878010bb3a8243a15a8d8df5 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:01 -0700 Subject: irq: make irqs in kernel stat use per_cpu_dyn_array Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 6f23059..b9d7137 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4048,9 +4048,12 @@ static inline void idle_balance(int cpu, struct rq *rq) #endif DEFINE_PER_CPU(struct kernel_stat, kstat); - EXPORT_PER_CPU_SYMBOL(kstat); +#ifdef CONFIG_HAVE_DYN_ARRAY +DEFINE_PER_CPU_DYN_ARRAY_ADDR(per_cpu__kstat_irqs, per_cpu__kstat.irqs, sizeof(unsigned int), nr_irqs, sizeof(unsigned long), NULL); +#endif + /* * Return p->sum_exec_runtime plus any more ns on the sched_clock * that have not yet been banked in case the task is currently running. -- cgit v1.1 From 08678b0841267c1d00d771fe01548d86043d065e Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:05 -0700 Subject: generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[] add CONFIG_HAVE_SPARSE_IRQ to for use condensed array. Get rid of irq_desc[] array assumptions. Preallocate 32 irq_desc, and irq_desc() will try to get more. ( No change in functionality is expected anywhere, except the odd build failure where we missed a code site or where a crossing commit itroduces new irq_desc[] usage. ) v2: according to Eric, change get_irq_desc() to irq_desc() Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/autoprobe.c | 10 ++-- kernel/irq/chip.c | 32 +++++++----- kernel/irq/handle.c | 138 ++++++++++++++++++++++++++++++++++++++++++++----- kernel/irq/manage.c | 35 +++++++------ kernel/irq/migration.c | 14 ++--- kernel/irq/proc.c | 36 +++++++------ kernel/irq/resend.c | 2 +- kernel/irq/spurious.c | 5 +- 8 files changed, 199 insertions(+), 73 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index c689e98..c45ab71 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -39,7 +39,7 @@ unsigned long probe_irq_on(void) * flush such a longstanding irq before considering it as spurious. */ for (i = nr_irqs-1; i > 0; i--) { - desc = irq_desc + i; + desc = irq_to_desc(i); spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { @@ -69,7 +69,7 @@ unsigned long probe_irq_on(void) * happened in the previous stage, it may have masked itself) */ for (i = nr_irqs-1; i > 0; i--) { - desc = irq_desc + i; + desc = irq_to_desc(i); spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { @@ -92,7 +92,7 @@ unsigned long probe_irq_on(void) for (i = 0; i < nr_irqs; i++) { unsigned int status; - desc = irq_desc + i; + desc = irq_to_desc(i); spin_lock_irq(&desc->lock); status = desc->status; @@ -131,7 +131,7 @@ unsigned int probe_irq_mask(unsigned long val) mask = 0; for (i = 0; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc = irq_to_desc(i); unsigned int status; spin_lock_irq(&desc->lock); @@ -174,7 +174,7 @@ int probe_irq_off(unsigned long val) int i, irq_found = 0, nr_irqs = 0; for (i = 0; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc = irq_to_desc(i); unsigned int status; spin_lock_irq(&desc->lock); diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index bba66e0..76c225c 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -33,7 +33,7 @@ void dynamic_irq_init(unsigned int irq) } /* Ensure we don't have left over values from a previous use of this irq */ - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->status = IRQ_DISABLED; desc->chip = &no_irq_chip; @@ -65,7 +65,7 @@ void dynamic_irq_cleanup(unsigned int irq) return; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); if (desc->action) { spin_unlock_irqrestore(&desc->lock, flags); @@ -100,7 +100,7 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) if (!chip) chip = &no_irq_chip; - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); irq_chip_set_defaults(chip); desc->chip = chip; @@ -126,7 +126,7 @@ int set_irq_type(unsigned int irq, unsigned int type) return -ENODEV; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); if (type == IRQ_TYPE_NONE) return 0; @@ -155,7 +155,7 @@ int set_irq_data(unsigned int irq, void *data) return -EINVAL; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->handler_data = data; spin_unlock_irqrestore(&desc->lock, flags); @@ -180,7 +180,7 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) "Trying to install msi data for IRQ%d\n", irq); return -EINVAL; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->msi_desc = entry; if (entry) @@ -198,9 +198,10 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) */ int set_irq_chip_data(unsigned int irq, void *data) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc; unsigned long flags; + desc = irq_to_desc(irq); if (irq >= nr_irqs || !desc->chip) { printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); return -EINVAL; @@ -219,8 +220,9 @@ EXPORT_SYMBOL(set_irq_chip_data); */ static void default_enable(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc; + desc = irq_to_desc(irq); desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED; } @@ -237,7 +239,10 @@ static void default_disable(unsigned int irq) */ static unsigned int default_startup(unsigned int irq) { - irq_desc[irq].chip->enable(irq); + struct irq_desc *desc; + + desc = irq_to_desc(irq); + desc->chip->enable(irq); return 0; } @@ -247,8 +252,9 @@ static unsigned int default_startup(unsigned int irq) */ static void default_shutdown(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc; + desc = irq_to_desc(irq); desc->chip->mask(irq); desc->status |= IRQ_MASKED; } @@ -551,7 +557,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, return; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); if (!handle) handle = handle_bad_irq; @@ -616,7 +622,7 @@ void __init set_irq_noprobe(unsigned int irq) return; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->status |= IRQ_NOPROBE; @@ -634,7 +640,7 @@ void __init set_irq_probe(unsigned int irq) return; } - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->status &= ~IRQ_NOPROBE; diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 6ce3bcc..9fc33b3 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -18,6 +18,14 @@ #include "internals.h" +#ifdef CONFIG_TRACE_IRQFLAGS + +/* + * lockdep: we want to handle all irq_desc locks as a single lock-class: + */ +static struct lock_class_key irq_desc_lock_class; +#endif + /** * handle_bad_irq - handle spurious and unhandled irqs * @irq: the interrupt number @@ -51,7 +59,8 @@ int nr_irqs = NR_IRQS; EXPORT_SYMBOL_GPL(nr_irqs); #ifdef CONFIG_HAVE_DYN_ARRAY -static struct irq_desc irq_desc_init __initdata = { +static struct irq_desc irq_desc_init = { + .irq = -1U, .status = IRQ_DISABLED, .chip = &no_irq_chip, .handle_irq = handle_bad_irq, @@ -62,6 +71,27 @@ static struct irq_desc irq_desc_init __initdata = { #endif }; + +static void init_one_irq_desc(struct irq_desc *desc) +{ + memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); +#ifdef CONFIG_TRACE_IRQFLAGS + lockdep_set_class(&desc->lock, &irq_desc_lock_class); +#endif +} + +#ifdef CONFIG_HAVE_SPARSE_IRQ +static int nr_irq_desc = 32; + +static int __init parse_nr_irq_desc(char *arg) +{ + if (arg) + nr_irq_desc = simple_strtoul(arg, NULL, 0); + return 0; +} + +early_param("nr_irq_desc", parse_nr_irq_desc); + static void __init init_work(void *data) { struct dyn_array *da = data; @@ -71,12 +101,83 @@ static void __init init_work(void *data) desc = *da->name; for (i = 0; i < *da->nr; i++) - memcpy(&desc[i], &irq_desc_init, sizeof(struct irq_desc)); + init_one_irq_desc(&desc[i]); + + for (i = 1; i < *da->nr; i++) + desc[i-1].next = &desc[i]; } -struct irq_desc *irq_desc; +static struct irq_desc *sparse_irqs; +DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); + +extern int after_bootmem; +extern void *__alloc_bootmem_nopanic(unsigned long size, + unsigned long align, + unsigned long goal); +struct irq_desc *irq_to_desc(unsigned int irq) +{ + struct irq_desc *desc, *desc_pri; + int i; + int count = 0; + + BUG_ON(irq == -1U); + + desc_pri = desc = &sparse_irqs[0]; + while (desc) { + if (desc->irq == irq) + return desc; + + if (desc->irq == -1U) { + desc->irq = irq; + return desc; + } + desc_pri = desc; + desc = desc->next; + count++; + } + + /* + * we run out of pre-allocate ones, allocate more + */ + printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); + + if (after_bootmem) + desc = kzalloc(sizeof(struct irq_desc)*nr_irq_desc, GFP_ATOMIC); + else + desc = __alloc_bootmem_nopanic(sizeof(struct irq_desc)*nr_irq_desc, PAGE_SIZE, 0); + + if (!desc) + panic("please boot with nr_irq_desc= %d\n", count * 2); + + for (i = 0; i < nr_irq_desc; i++) + init_one_irq_desc(&desc[i]); + + for (i = 1; i < nr_irq_desc; i++) + desc[i-1].next = &desc[i]; + + desc->irq = irq; + desc_pri->next = desc; + + return desc; +} +#else +static void __init init_work(void *data) +{ + struct dyn_array *da = data; + int i; + struct irq_desc *desc; + + desc = *da->name; + + for (i = 0; i < *da->nr; i++) + init_one_irq_desc(&desc[i]); + +} +static struct irq_desc *irq_desc; DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); +#endif + #else struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { @@ -85,12 +186,23 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { .chip = &no_irq_chip, .handle_irq = handle_bad_irq, .depth = 1, - .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock), + .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock), #ifdef CONFIG_SMP .affinity = CPU_MASK_ALL #endif } }; + +#endif + +#ifndef CONFIG_HAVE_SPARSE_IRQ +struct irq_desc *irq_to_desc(unsigned int irq) +{ + if (irq < nr_irqs) + return &irq_desc[irq]; + + return NULL; +} #endif /* @@ -99,7 +211,10 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { */ static void ack_bad(unsigned int irq) { - print_irq_desc(irq, irq_desc + irq); + struct irq_desc *desc; + + desc = irq_to_desc(irq); + print_irq_desc(irq, desc); ack_bad_irq(irq); } @@ -196,7 +311,7 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) */ unsigned int __do_IRQ(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; unsigned int status; @@ -287,19 +402,16 @@ out: } #endif -#ifdef CONFIG_TRACE_IRQFLAGS - -/* - * lockdep: we want to handle all irq_desc locks as a single lock-class: - */ -static struct lock_class_key irq_desc_lock_class; +#ifdef CONFIG_TRACE_IRQFLAGS void early_init_irq_lock_class(void) { +#ifndef CONFIG_HAVE_DYN_ARRAY int i; for (i = 0; i < nr_irqs; i++) lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class); +#endif } - #endif + diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index d5a4333..b5943e9 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -31,7 +31,7 @@ cpumask_t irq_default_affinity = CPU_MASK_ALL; */ void synchronize_irq(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); unsigned int status; if (irq >= nr_irqs) @@ -64,7 +64,7 @@ EXPORT_SYMBOL(synchronize_irq); */ int irq_can_set_affinity(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || !desc->chip->set_affinity) @@ -81,7 +81,7 @@ int irq_can_set_affinity(unsigned int irq) */ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); if (!desc->chip->set_affinity) return -EINVAL; @@ -111,14 +111,16 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) int irq_select_affinity(unsigned int irq) { cpumask_t mask; + struct irq_desc *desc; if (!irq_can_set_affinity(irq)) return 0; cpus_and(mask, cpu_online_map, irq_default_affinity); - irq_desc[irq].affinity = mask; - irq_desc[irq].chip->set_affinity(irq, mask); + desc = irq_to_desc(irq); + desc->affinity = mask; + desc->chip->set_affinity(irq, mask); set_balance_irq_affinity(irq, mask); return 0; @@ -140,7 +142,7 @@ int irq_select_affinity(unsigned int irq) */ void disable_irq_nosync(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; if (irq >= nr_irqs) @@ -169,7 +171,7 @@ EXPORT_SYMBOL(disable_irq_nosync); */ void disable_irq(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); if (irq >= nr_irqs) return; @@ -211,7 +213,7 @@ static void __enable_irq(struct irq_desc *desc, unsigned int irq) */ void enable_irq(unsigned int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; if (irq >= nr_irqs) @@ -225,7 +227,7 @@ EXPORT_SYMBOL(enable_irq); static int set_irq_wake_real(unsigned int irq, unsigned int on) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); int ret = -ENXIO; if (desc->chip->set_wake) @@ -248,7 +250,7 @@ static int set_irq_wake_real(unsigned int irq, unsigned int on) */ int set_irq_wake(unsigned int irq, unsigned int on) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; int ret = 0; @@ -288,12 +290,13 @@ EXPORT_SYMBOL(set_irq_wake); */ int can_request_irq(unsigned int irq, unsigned long irqflags) { + struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; - if (irq >= nr_irqs || irq_desc[irq].status & IRQ_NOREQUEST) + if (irq >= nr_irqs || desc->status & IRQ_NOREQUEST) return 0; - action = irq_desc[irq].action; + action = desc->action; if (action) if (irqflags & action->flags & IRQF_SHARED) action = NULL; @@ -349,7 +352,7 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, */ int setup_irq(unsigned int irq, struct irqaction *new) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); struct irqaction *old, **p; const char *old_name = NULL; unsigned long flags; @@ -518,7 +521,7 @@ void free_irq(unsigned int irq, void *dev_id) if (irq >= nr_irqs) return; - desc = irq_desc + irq; + desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); p = &desc->action; for (;;) { @@ -615,6 +618,7 @@ int request_irq(unsigned int irq, irq_handler_t handler, { struct irqaction *action; int retval; + struct irq_desc *desc; #ifdef CONFIG_LOCKDEP /* @@ -632,7 +636,8 @@ int request_irq(unsigned int irq, irq_handler_t handler, return -EINVAL; if (irq >= nr_irqs) return -EINVAL; - if (irq_desc[irq].status & IRQ_NOREQUEST) + desc = irq_to_desc(irq); + if (desc->status & IRQ_NOREQUEST) return -EINVAL; if (!handler) return -EINVAL; diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 77b7acc..90b920d 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -3,18 +3,18 @@ void set_pending_irq(unsigned int irq, cpumask_t mask) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; spin_lock_irqsave(&desc->lock, flags); desc->status |= IRQ_MOVE_PENDING; - irq_desc[irq].pending_mask = mask; + desc->pending_mask = mask; spin_unlock_irqrestore(&desc->lock, flags); } void move_masked_irq(int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); cpumask_t tmp; if (likely(!(desc->status & IRQ_MOVE_PENDING))) @@ -30,7 +30,7 @@ void move_masked_irq(int irq) desc->status &= ~IRQ_MOVE_PENDING; - if (unlikely(cpus_empty(irq_desc[irq].pending_mask))) + if (unlikely(cpus_empty(desc->pending_mask))) return; if (!desc->chip->set_affinity) @@ -38,7 +38,7 @@ void move_masked_irq(int irq) assert_spin_locked(&desc->lock); - cpus_and(tmp, irq_desc[irq].pending_mask, cpu_online_map); + cpus_and(tmp, desc->pending_mask, cpu_online_map); /* * If there was a valid mask to work with, please @@ -55,12 +55,12 @@ void move_masked_irq(int irq) if (likely(!cpus_empty(tmp))) { desc->chip->set_affinity(irq,tmp); } - cpus_clear(irq_desc[irq].pending_mask); + cpus_clear(desc->pending_mask); } void move_native_irq(int irq) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); if (likely(!(desc->status & IRQ_MOVE_PENDING))) return; diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index e5225a6..c2f356c 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -19,7 +19,7 @@ static struct proc_dir_entry *root_irq_dir; static int irq_affinity_proc_show(struct seq_file *m, void *v) { - struct irq_desc *desc = irq_desc + (long)m->private; + struct irq_desc *desc = irq_to_desc((long)m->private); cpumask_t *mask = &desc->affinity; #ifdef CONFIG_GENERIC_PENDING_IRQ @@ -43,7 +43,7 @@ static ssize_t irq_affinity_proc_write(struct file *file, cpumask_t new_value; int err; - if (!irq_desc[irq].chip->set_affinity || no_irq_affinity || + if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity || irq_balancing_disabled(irq)) return -EIO; @@ -132,20 +132,20 @@ static const struct file_operations default_affinity_proc_fops = { static int irq_spurious_read(char *page, char **start, off_t off, int count, int *eof, void *data) { - struct irq_desc *d = &irq_desc[(long) data]; + struct irq_desc *desc = irq_to_desc((long) data); return sprintf(page, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n", - d->irq_count, - d->irqs_unhandled, - jiffies_to_msecs(d->last_unhandled)); + desc->irq_count, + desc->irqs_unhandled, + jiffies_to_msecs(desc->last_unhandled)); } #define MAX_NAMELEN 128 static int name_unique(unsigned int irq, struct irqaction *new_action) { - struct irq_desc *desc = irq_desc + irq; + struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; unsigned long flags; int ret = 1; @@ -165,8 +165,9 @@ static int name_unique(unsigned int irq, struct irqaction *new_action) void register_handler_proc(unsigned int irq, struct irqaction *action) { char name [MAX_NAMELEN]; + struct irq_desc *desc = irq_to_desc(irq); - if (!irq_desc[irq].dir || action->dir || !action->name || + if (!desc->dir || action->dir || !action->name || !name_unique(irq, action)) return; @@ -174,7 +175,7 @@ void register_handler_proc(unsigned int irq, struct irqaction *action) snprintf(name, MAX_NAMELEN, "%s", action->name); /* create /proc/irq/1234/handler/ */ - action->dir = proc_mkdir(name, irq_desc[irq].dir); + action->dir = proc_mkdir(name, desc->dir); } #undef MAX_NAMELEN @@ -185,25 +186,24 @@ void register_irq_proc(unsigned int irq) { char name [MAX_NAMELEN]; struct proc_dir_entry *entry; + struct irq_desc *desc = irq_to_desc(irq); - if (!root_irq_dir || - (irq_desc[irq].chip == &no_irq_chip) || - irq_desc[irq].dir) + if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir) return; memset(name, 0, MAX_NAMELEN); sprintf(name, "%d", irq); /* create /proc/irq/1234 */ - irq_desc[irq].dir = proc_mkdir(name, root_irq_dir); + desc->dir = proc_mkdir(name, root_irq_dir); #ifdef CONFIG_SMP /* create /proc/irq//smp_affinity */ - proc_create_data("smp_affinity", 0600, irq_desc[irq].dir, + proc_create_data("smp_affinity", 0600, desc->dir, &irq_affinity_proc_fops, (void *)(long)irq); #endif - entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir); + entry = create_proc_entry("spurious", 0444, desc->dir); if (entry) { entry->data = (void *)(long)irq; entry->read_proc = irq_spurious_read; @@ -214,8 +214,10 @@ void register_irq_proc(unsigned int irq) void unregister_handler_proc(unsigned int irq, struct irqaction *action) { - if (action->dir) - remove_proc_entry(action->dir->name, irq_desc[irq].dir); + if (action->dir) { + struct irq_desc *desc = irq_to_desc(irq); + remove_proc_entry(action->dir->name, desc->dir); + } } void register_default_affinity_proc(void) diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index cba8aa5..89c7117 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -36,7 +36,7 @@ static void resend_irqs(unsigned long arg) while (!bitmap_empty(irqs_resend, nr_irqs)) { irq = find_first_bit(irqs_resend, nr_irqs); clear_bit(irq, irqs_resend); - desc = irq_desc + irq; + desc = irq_to_desc(irq); local_irq_disable(); desc->handle_irq(irq, desc); local_irq_enable(); diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index e26ca1e..b5d9060 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -92,11 +92,12 @@ static int misrouted_irq(int irq) int ok = 0; for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc; if (i == irq) /* Already tried */ continue; + desc = irq_to_desc(i); if (try_one_irq(i, desc)) ok = 1; } @@ -108,7 +109,7 @@ static void poll_spurious_irqs(unsigned long dummy) { int i; for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc = irq_to_desc(i); unsigned int status; /* Racy but it doesn't matter */ -- cgit v1.1 From 3bf52a4df3ccd25d4154797977c556a2a8b3bc1e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 19 Aug 2008 20:50:29 -0700 Subject: irq: sparse irqs, fix IRQ auto-probe crash fix: [ 10.631533] calling yenta_socket_init+0x0/0x20 [ 10.631533] Yenta: CardBus bridge found at 0000:15:00.0 [17aa:2012] [ 10.631533] Yenta: Using INTVAL to route CSC interrupts to PCI [ 10.631533] Yenta: Routing CardBus interrupts to PCI [ 10.631533] Yenta TI: socket 0000:15:00.0, mfunc 0x01d01002, devctl 0x64 [ 10.731599] BUG: unable to handle kernel NULL pointer dereference at 00000040 [ 10.731838] IP: [] _spin_lock_irq+0xf/0x20 [ 10.732221] *pde = 00000000 [ 10.732741] Oops: 0002 [#1] SMP [ 10.733453] [ 10.734253] Pid: 1, comm: swapper Tainted: G W (2.6.27-rc3-tip-00173-gd7eaa4f-dirty #1) [ 10.735188] EIP: 0060:[] EFLAGS: 00010002 CPU: 0 [ 10.735523] EIP is at _spin_lock_irq+0xf/0x20 [ 10.735523] EAX: 00000040 EBX: 00000000 ECX: f6e04c90 EDX: 00000100 [ 10.735523] ESI: 000000df EDI: f6e04c90 EBP: f7867df0 ESP: f7867df0 [ 10.735523] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 10.735523] Process swapper (pid: 1, ti=f7867000 task=f7870000 task.ti=f7867000) [ 10.735523] Stack: f7867e04 c0155fbd 00000000 00000000 f6e04c90 f7867e5c c0c6e319 c0f6a074 [ 10.735523] f6e04c90 000017aa 00002012 c112b648 f791f240 c112b5e0 f7867e44 c010440b [ 10.735523] f791f240 f791f29c c112b8ec f791f240 00000000 f7867e5c c048f893 03c0b648 [ 10.735523] Call Trace: [ 10.735523] [] ? probe_irq_on+0x3d/0x140 [ 10.735523] [] ? yenta_probe+0x529/0x640 [ 10.735523] [] ? mcount_call+0x5/0xa [ 10.735523] [] ? pci_match_device+0xa3/0xb0 [ 10.735523] [] ? pci_device_probe+0x5e/0x80 [ 10.735523] [] ? driver_probe_device+0x83/0x180 [ 10.735523] [] ? __driver_attach+0x74/0x80 [ 10.735523] [] ? bus_for_each_dev+0x49/0x70 [ 10.735523] [] ? driver_attach+0x1e/0x20 [ 10.735523] [] ? __driver_attach+0x0/0x80 [ 10.735523] [] ? bus_add_driver+0x1a3/0x220 [ 10.735523] [] ? pci_device_remove+0x0/0x40 [ 10.735523] [] ? driver_register+0x54/0x130 [ 10.735523] [] ? __pci_register_driver+0x4f/0x90 [ 10.735523] [] ? yenta_socket_init+0x19/0x20 [ 10.735523] [] ? do_one_initcall+0x35/0x160 [ 10.735523] [] ? yenta_socket_init+0x0/0x20 [ 10.735523] [] ? __queue_work+0x36/0x50 [ 10.735523] [] ? queue_work_on+0x3d/0x50 [ 10.735523] [] ? kernel_init+0x148/0x210 [ 10.735523] [] ? kernel_init+0x0/0x210 [ 10.735523] [] ? kernel_thread_helper+0x7/0x10 [ 10.735523] ======================= [ 10.735523] Code: 10 38 f2 74 06 f3 90 8a 10 eb f6 5d 89 c8 c3 8d b6 00 00 00 00 8d bc 27 00 00 00 00 55 89 e5 e8 a4 e8 46 ff fa ba 00 01 00 00 90 <66> 0f c1 10 38 f2 74 06 f3 90 8a 10 eb f6 5d c3 90 55 89 e5 53 as auto-probing wants to iterate over existing irqs. Signed-off-by: Ingo Molnar --- kernel/irq/autoprobe.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel') diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index c45ab71..b3a5549 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -40,6 +40,8 @@ unsigned long probe_irq_on(void) */ for (i = nr_irqs-1; i > 0; i--) { desc = irq_to_desc(i); + if (!desc) + continue; spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { @@ -70,6 +72,8 @@ unsigned long probe_irq_on(void) */ for (i = nr_irqs-1; i > 0; i--) { desc = irq_to_desc(i); + if (!desc) + continue; spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { @@ -93,6 +97,8 @@ unsigned long probe_irq_on(void) unsigned int status; desc = irq_to_desc(i); + if (!desc) + continue; spin_lock_irq(&desc->lock); status = desc->status; @@ -134,6 +140,8 @@ unsigned int probe_irq_mask(unsigned long val) struct irq_desc *desc = irq_to_desc(i); unsigned int status; + if (!desc) + continue; spin_lock_irq(&desc->lock); status = desc->status; @@ -177,6 +185,8 @@ int probe_irq_off(unsigned long val) struct irq_desc *desc = irq_to_desc(i); unsigned int status; + if (!desc) + continue; spin_lock_irq(&desc->lock); status = desc->status; -- cgit v1.1 From 7f95ec9e4c12fd067febfd57532da1166d75d858 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:09 -0700 Subject: x86: move kstat_irqs from kstat to irq_desc based on Eric's patch ... together mold it with dyn_array for irq_desc, will allcate kstat_irqs for nr_irq_desc alltogether if needed. -- at that point nr_cpus is known already. v2: make sure system without generic_hardirqs works they don't have irq_desc v3: fix merging v4: [mingo@elte.hu] fix typo [ mingo@elte.hu ] irq: build fix fix: arch/x86/xen/spinlock.c: In function 'xen_spin_lock_slow': arch/x86/xen/spinlock.c:90: error: 'struct kernel_stat' has no member named 'irqs' Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 15 +++------ kernel/irq/handle.c | 97 ++++++++++++++++++++++++++++++++++++++--------------- kernel/sched.c | 5 +-- 3 files changed, 76 insertions(+), 41 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 76c225c..2aa3d4b2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -312,14 +312,13 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc) { struct irqaction *action; irqreturn_t action_ret; - const unsigned int cpu = smp_processor_id(); spin_lock(&desc->lock); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); - kstat_cpu(cpu).irqs[irq]++; + kstat_irqs_this_cpu(desc)++; action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) @@ -351,7 +350,6 @@ out_unlock: void handle_level_irq(unsigned int irq, struct irq_desc *desc) { - unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; @@ -361,7 +359,7 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); - kstat_cpu(cpu).irqs[irq]++; + kstat_irqs_this_cpu(desc)++; /* * If its disabled or no action available @@ -399,7 +397,6 @@ out_unlock: void handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) { - unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; @@ -409,7 +406,7 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) goto out; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); - kstat_cpu(cpu).irqs[irq]++; + kstat_irqs_this_cpu(desc)++; /* * If its disabled or no action available @@ -458,8 +455,6 @@ out: void handle_edge_irq(unsigned int irq, struct irq_desc *desc) { - const unsigned int cpu = smp_processor_id(); - spin_lock(&desc->lock); desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); @@ -476,7 +471,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc) goto out_unlock; } - kstat_cpu(cpu).irqs[irq]++; + kstat_irqs_this_cpu(desc)++; /* Start handling the irq */ desc->chip->ack(irq); @@ -531,7 +526,7 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc) { irqreturn_t action_ret; - kstat_this_cpu.irqs[irq]++; + kstat_irqs_this_cpu(desc)++; if (desc->chip->ack) desc->chip->ack(irq); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 9fc33b3..1f34699 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -37,7 +37,7 @@ void handle_bad_irq(unsigned int irq, struct irq_desc *desc) { print_irq_desc(irq, desc); - kstat_this_cpu.irqs[irq]++; + kstat_irqs_this_cpu(desc)++; ack_bad_irq(irq); } @@ -80,17 +80,38 @@ static void init_one_irq_desc(struct irq_desc *desc) #endif } -#ifdef CONFIG_HAVE_SPARSE_IRQ -static int nr_irq_desc = 32; +extern int after_bootmem; +extern void *__alloc_bootmem_nopanic(unsigned long size, + unsigned long align, + unsigned long goal); -static int __init parse_nr_irq_desc(char *arg) +static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) { - if (arg) - nr_irq_desc = simple_strtoul(arg, NULL, 0); - return 0; + unsigned long bytes, total_bytes; + char *ptr; + int i; + unsigned long phys; + + /* Compute how many bytes we need per irq and allocate them */ + bytes = nr * sizeof(unsigned int); + total_bytes = bytes * nr_desc; + if (after_bootmem) + ptr = kzalloc(total_bytes, GFP_ATOMIC); + else + ptr = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); + + if (!ptr) + panic(" can not allocate kstat_irqs\n"); + + phys = __pa(ptr); + printk(KERN_DEBUG "kstat_irqs ==> [%#lx - %#lx]\n", phys, phys + total_bytes); + + for (i = 0; i < nr_desc; i++) { + desc[i].kstat_irqs = (unsigned int *)ptr; + ptr += bytes; + } } -early_param("nr_irq_desc", parse_nr_irq_desc); static void __init init_work(void *data) { @@ -100,25 +121,44 @@ static void __init init_work(void *data) desc = *da->name; - for (i = 0; i < *da->nr; i++) + for (i = 0; i < *da->nr; i++) { init_one_irq_desc(&desc[i]); +#ifndef CONFIG_HAVE_SPARSE_IRQ + desc[i].irq = i; +#endif + } +#ifdef CONFIG_HAVE_SPARSE_IRQ for (i = 1; i < *da->nr; i++) desc[i-1].next = &desc[i]; +#endif + + /* init kstat_irqs, nr_cpu_ids is ready already */ + init_kstat_irqs(desc, *da->nr, nr_cpu_ids); } +#ifdef CONFIG_HAVE_SPARSE_IRQ +static int nr_irq_desc = 32; + +static int __init parse_nr_irq_desc(char *arg) +{ + if (arg) + nr_irq_desc = simple_strtoul(arg, NULL, 0); + return 0; +} + +early_param("nr_irq_desc", parse_nr_irq_desc); + static struct irq_desc *sparse_irqs; DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); -extern int after_bootmem; -extern void *__alloc_bootmem_nopanic(unsigned long size, - unsigned long align, - unsigned long goal); struct irq_desc *irq_to_desc(unsigned int irq) { struct irq_desc *desc, *desc_pri; int i; int count = 0; + unsigned long phys; + unsigned long total_bytes; BUG_ON(irq == -1U); @@ -141,38 +181,34 @@ struct irq_desc *irq_to_desc(unsigned int irq) */ printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); + total_bytes = sizeof(struct irq_desc) * nr_irq_desc; if (after_bootmem) - desc = kzalloc(sizeof(struct irq_desc)*nr_irq_desc, GFP_ATOMIC); + desc = kzalloc(total_bytes, GFP_ATOMIC); else - desc = __alloc_bootmem_nopanic(sizeof(struct irq_desc)*nr_irq_desc, PAGE_SIZE, 0); + desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); if (!desc) panic("please boot with nr_irq_desc= %d\n", count * 2); + phys = __pa(desc); + printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes); + for (i = 0; i < nr_irq_desc; i++) init_one_irq_desc(&desc[i]); for (i = 1; i < nr_irq_desc; i++) desc[i-1].next = &desc[i]; + /* init kstat_irqs, nr_cpu_ids is ready already */ + init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids); + desc->irq = irq; desc_pri->next = desc; return desc; } #else -static void __init init_work(void *data) -{ - struct dyn_array *da = data; - int i; - struct irq_desc *desc; - - desc = *da->name; - for (i = 0; i < *da->nr; i++) - init_one_irq_desc(&desc[i]); - -} static struct irq_desc *irq_desc; DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); @@ -315,7 +351,7 @@ unsigned int __do_IRQ(unsigned int irq) struct irqaction *action; unsigned int status; - kstat_this_cpu.irqs[irq]++; + kstat_irqs_this_cpu(desc)++; if (CHECK_IRQ_PER_CPU(desc->status)) { irqreturn_t action_ret; @@ -415,3 +451,10 @@ void early_init_irq_lock_class(void) } #endif +unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) +{ + struct irq_desc *desc = irq_to_desc(irq); + return desc->kstat_irqs[cpu]; +} +EXPORT_SYMBOL(kstat_irqs_cpu); + diff --git a/kernel/sched.c b/kernel/sched.c index b9d7137..6f23059 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4048,11 +4048,8 @@ static inline void idle_balance(int cpu, struct rq *rq) #endif DEFINE_PER_CPU(struct kernel_stat, kstat); -EXPORT_PER_CPU_SYMBOL(kstat); -#ifdef CONFIG_HAVE_DYN_ARRAY -DEFINE_PER_CPU_DYN_ARRAY_ADDR(per_cpu__kstat_irqs, per_cpu__kstat.irqs, sizeof(unsigned int), nr_irqs, sizeof(unsigned long), NULL); -#endif +EXPORT_PER_CPU_SYMBOL(kstat); /* * Return p->sum_exec_runtime plus any more ns on the sched_clock -- cgit v1.1 From 9059d8fa4a3a9153da53da890039f7f956cc9d19 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:10 -0700 Subject: irq: add irq_desc_without_new add an irq_desc accessor that will not allocate any sparse entry but returns failure if there's no entry present. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 1f34699..8e55dbe 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -112,7 +112,6 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) } } - static void __init init_work(void *data) { struct dyn_array *da = data; @@ -149,9 +148,27 @@ static int __init parse_nr_irq_desc(char *arg) early_param("nr_irq_desc", parse_nr_irq_desc); -static struct irq_desc *sparse_irqs; +struct irq_desc *sparse_irqs; DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); +struct irq_desc *__irq_to_desc(unsigned int irq) +{ + struct irq_desc *desc; + + BUG_ON(irq == -1U); + + desc = &sparse_irqs[0]; + while (desc) { + if (desc->irq == irq) + return desc; + + if (desc->irq == -1U) + return NULL; + + desc = desc->next; + } + return NULL; +} struct irq_desc *irq_to_desc(unsigned int irq) { struct irq_desc *desc, *desc_pri; @@ -208,8 +225,7 @@ struct irq_desc *irq_to_desc(unsigned int irq) return desc; } #else - -static struct irq_desc *irq_desc; +struct irq_desc *irq_desc; DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); #endif @@ -239,6 +255,10 @@ struct irq_desc *irq_to_desc(unsigned int irq) return NULL; } +struct irq_desc *__irq_to_desc(unsigned int irq) +{ + return irq_to_desc(irq); +} #endif /* -- cgit v1.1 From 2c6927a38f65b53b62f86158fba29a068c4e8b6a Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:11 -0700 Subject: irq: replace loop with nr_irqs with for_each_irq_desc There are a handful of loops that go from 0 to nr_irqs and use get_irq_desc() on them. These would allocate all the irq_desc entries, regardless of the need for them. Use the smarter for_each_irq_desc() iterator that will only iterate over the present ones. v2: make sure arch without GENERIC_HARDIRQS work too Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/internals.h | 4 ++-- kernel/irq/manage.c | 2 +- kernel/irq/proc.c | 10 +++++----- 3 files changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 422dd00..c9767e6 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -14,11 +14,11 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, unsigned long flags); #ifdef CONFIG_PROC_FS -extern void register_irq_proc(unsigned int irq); +extern void register_irq_proc(unsigned int irq, struct irq_desc *desc); extern void register_handler_proc(unsigned int irq, struct irqaction *action); extern void unregister_handler_proc(unsigned int irq, struct irqaction *action); #else -static inline void register_irq_proc(unsigned int irq) { } +static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { } static inline void register_handler_proc(unsigned int irq, struct irqaction *action) { } static inline void unregister_handler_proc(unsigned int irq, diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index b5943e9..5070f55 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -478,7 +478,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) spin_unlock_irqrestore(&desc->lock, flags); new->irq = irq; - register_irq_proc(irq); + register_irq_proc(irq, desc); new->dir = NULL; register_handler_proc(irq, new); diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index c2f356c..bc0993d 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -182,11 +182,10 @@ void register_handler_proc(unsigned int irq, struct irqaction *action) #define MAX_NAMELEN 10 -void register_irq_proc(unsigned int irq) +void register_irq_proc(unsigned int irq, struct irq_desc *desc) { char name [MAX_NAMELEN]; struct proc_dir_entry *entry; - struct irq_desc *desc = irq_to_desc(irq); if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir) return; @@ -230,7 +229,8 @@ void register_default_affinity_proc(void) void init_irq_proc(void) { - int i; + unsigned int irq; + struct irq_desc *desc; /* create /proc/irq */ root_irq_dir = proc_mkdir("irq", NULL); @@ -242,7 +242,7 @@ void init_irq_proc(void) /* * Create entries for all existing IRQs. */ - for (i = 0; i < nr_irqs; i++) - register_irq_proc(i); + for_each_irq_desc(irq, desc) + register_irq_proc(irq, desc); } -- cgit v1.1 From 7d94f7ca401dd7f445fda9a971a48aa5427b3e55 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:14 -0700 Subject: irq: remove >= nr_irqs checking with config_have_sparse_irq remove irq limit checks - nr_irqs is dynamic and we expand anytime. v2: fix checking about result irq_cfg_without_new, so could use msi again v3: use irq_desc_without_new to check irq is valid Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 49 +++++++++++++++++++++++++++---------------------- kernel/irq/manage.c | 43 +++++++++++++++++++++++++++---------------- 2 files changed, 54 insertions(+), 38 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 2aa3d4b2..a4bb0da 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -27,13 +27,13 @@ void dynamic_irq_init(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = irq_to_desc(irq); + if (!desc) { WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; } /* Ensure we don't have left over values from a previous use of this irq */ - desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->status = IRQ_DISABLED; desc->chip = &no_irq_chip; @@ -60,12 +60,12 @@ void dynamic_irq_cleanup(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); return; } - desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); if (desc->action) { spin_unlock_irqrestore(&desc->lock, flags); @@ -92,7 +92,8 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq); return -EINVAL; } @@ -121,12 +122,12 @@ int set_irq_type(unsigned int irq, unsigned int type) unsigned long flags; int ret = -ENXIO; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; } - desc = irq_to_desc(irq); if (type == IRQ_TYPE_NONE) return 0; @@ -149,13 +150,13 @@ int set_irq_data(unsigned int irq, void *data) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); return -EINVAL; } - desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); desc->handler_data = data; spin_unlock_irqrestore(&desc->lock, flags); @@ -175,12 +176,13 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); return -EINVAL; } - desc = irq_to_desc(irq); + spin_lock_irqsave(&desc->lock, flags); desc->msi_desc = entry; if (entry) @@ -201,8 +203,14 @@ int set_irq_chip_data(unsigned int irq, void *data) struct irq_desc *desc; unsigned long flags; - desc = irq_to_desc(irq); - if (irq >= nr_irqs || !desc->chip) { + desc = __irq_to_desc(irq); + if (!desc) { + printk(KERN_ERR + "Trying to install chip data for IRQ%d\n", irq); + return -EINVAL; + } + + if (!desc->chip) { printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); return -EINVAL; } @@ -546,14 +554,13 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to install type control for IRQ%d\n", irq); return; } - desc = irq_to_desc(irq); - if (!handle) handle = handle_bad_irq; else if (desc->chip == &no_irq_chip) { @@ -611,14 +618,13 @@ void __init set_irq_noprobe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq); return; } - desc = irq_to_desc(irq); - spin_lock_irqsave(&desc->lock, flags); desc->status |= IRQ_NOPROBE; spin_unlock_irqrestore(&desc->lock, flags); @@ -629,14 +635,13 @@ void __init set_irq_probe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) { + desc = __irq_to_desc(irq); + if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq); return; } - desc = irq_to_desc(irq); - spin_lock_irqsave(&desc->lock, flags); desc->status &= ~IRQ_NOPROBE; spin_unlock_irqrestore(&desc->lock, flags); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 5070f55..c0b4d4d 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -31,10 +31,10 @@ cpumask_t irq_default_affinity = CPU_MASK_ALL; */ void synchronize_irq(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc = __irq_to_desc(irq); unsigned int status; - if (irq >= nr_irqs) + if (!desc) return; do { @@ -142,10 +142,11 @@ int irq_select_affinity(unsigned int irq) */ void disable_irq_nosync(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) + desc = __irq_to_desc(irq); + if (!desc) return; spin_lock_irqsave(&desc->lock, flags); @@ -171,9 +172,10 @@ EXPORT_SYMBOL(disable_irq_nosync); */ void disable_irq(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc; - if (irq >= nr_irqs) + desc = __irq_to_desc(irq); + if (!desc) return; disable_irq_nosync(irq); @@ -213,10 +215,11 @@ static void __enable_irq(struct irq_desc *desc, unsigned int irq) */ void enable_irq(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc; unsigned long flags; - if (irq >= nr_irqs) + desc = __irq_to_desc(irq); + if (!desc) return; spin_lock_irqsave(&desc->lock, flags); @@ -290,10 +293,14 @@ EXPORT_SYMBOL(set_irq_wake); */ int can_request_irq(unsigned int irq, unsigned long irqflags) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc; struct irqaction *action; - if (irq >= nr_irqs || desc->status & IRQ_NOREQUEST) + desc = __irq_to_desc(irq); + if (!desc) + return 0; + + if (desc->status & IRQ_NOREQUEST) return 0; action = desc->action; @@ -352,14 +359,15 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, */ int setup_irq(unsigned int irq, struct irqaction *new) { - struct irq_desc *desc = irq_to_desc(irq); + struct irq_desc *desc; struct irqaction *old, **p; const char *old_name = NULL; unsigned long flags; int shared = 0; int ret; - if (irq >= nr_irqs) + desc = __irq_to_desc(irq); + if (!desc) return -EINVAL; if (desc->chip == &no_irq_chip) @@ -518,10 +526,11 @@ void free_irq(unsigned int irq, void *dev_id) unsigned long flags; WARN_ON(in_interrupt()); - if (irq >= nr_irqs) + + desc = __irq_to_desc(irq); + if (!desc) return; - desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); p = &desc->action; for (;;) { @@ -634,9 +643,11 @@ int request_irq(unsigned int irq, irq_handler_t handler, */ if ((irqflags & IRQF_SHARED) && !dev_id) return -EINVAL; - if (irq >= nr_irqs) + + desc = __irq_to_desc(irq); + if (!desc) return -EINVAL; - desc = irq_to_desc(irq); + if (desc->status & IRQ_NOREQUEST) return -EINVAL; if (!handler) -- cgit v1.1 From 46926b67fc663d357a1a8174328998a9e49da0b8 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:15 -0700 Subject: generic: add irq_desc in function in parameter So we could remove some duplicated calling to irq_desc v2: make sure irq_desc in init/main.c is not used without generic_hardirqs Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 8e55dbe..e1d787e 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -197,6 +197,21 @@ struct irq_desc *irq_to_desc(unsigned int irq) * we run out of pre-allocate ones, allocate more */ printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); + { + /* double check if some one mess up the list */ + struct irq_desc *desc; + int count = 0; + + desc = &sparse_irqs[0]; + while (desc) { + printk(KERN_DEBUG "found irq_desc for irq %d\n", desc->irq); + if (desc->next) + printk(KERN_DEBUG "found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq); + desc = desc->next; + count++; + } + printk(KERN_DEBUG "all preallocted %d\n", count); + } total_bytes = sizeof(struct irq_desc) * nr_irq_desc; if (after_bootmem) @@ -221,6 +236,21 @@ struct irq_desc *irq_to_desc(unsigned int irq) desc->irq = irq; desc_pri->next = desc; + { + /* double check if some one mess up the list */ + struct irq_desc *desc; + int count = 0; + + desc = &sparse_irqs[0]; + while (desc) { + printk(KERN_DEBUG "1 found irq_desc for irq %d\n", desc->irq); + if (desc->next) + printk(KERN_DEBUG "1 found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq); + desc = desc->next; + count++; + } + printk(KERN_DEBUG "1 all preallocted %d\n", count); + } return desc; } -- cgit v1.1 From cb5bc83225a86ca53bbb889ed8439e4fd6cf44ac Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:17 -0700 Subject: x86_64: rename irq_desc/irq_desc_alloc change names: irq_desc() ==> irq_desc_alloc __irq_desc() ==> irq_desc Also split a few of the uses in lowlevel x86 code. v2: need to check if desc is null in smp_irq_move_cleanup Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 21 +++++++++++---------- kernel/irq/handle.c | 23 +++++------------------ kernel/irq/manage.c | 16 ++++++++-------- 3 files changed, 24 insertions(+), 36 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index a4bb0da..9fc5e69 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -27,7 +27,8 @@ void dynamic_irq_init(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = irq_to_desc(irq); + /* first time to use this irq_desc */ + desc = irq_to_desc_alloc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; @@ -60,7 +61,7 @@ void dynamic_irq_cleanup(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); return; @@ -92,7 +93,7 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq); return -EINVAL; @@ -122,7 +123,7 @@ int set_irq_type(unsigned int irq, unsigned int type) unsigned long flags; int ret = -ENXIO; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; @@ -150,7 +151,7 @@ int set_irq_data(unsigned int irq, void *data) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); @@ -176,7 +177,7 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); @@ -203,7 +204,7 @@ int set_irq_chip_data(unsigned int irq, void *data) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install chip data for IRQ%d\n", irq); @@ -554,7 +555,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install type control for IRQ%d\n", irq); @@ -618,7 +619,7 @@ void __init set_irq_noprobe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq); @@ -635,7 +636,7 @@ void __init set_irq_probe(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index e1d787e..d44e351 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -151,7 +151,7 @@ early_param("nr_irq_desc", parse_nr_irq_desc); struct irq_desc *sparse_irqs; DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); -struct irq_desc *__irq_to_desc(unsigned int irq) +struct irq_desc *irq_to_desc(unsigned int irq) { struct irq_desc *desc; @@ -169,7 +169,7 @@ struct irq_desc *__irq_to_desc(unsigned int irq) } return NULL; } -struct irq_desc *irq_to_desc(unsigned int irq) +struct irq_desc *irq_to_desc_alloc(unsigned int irq) { struct irq_desc *desc, *desc_pri; int i; @@ -186,6 +186,7 @@ struct irq_desc *irq_to_desc(unsigned int irq) if (desc->irq == -1U) { desc->irq = irq; + printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); return desc; } desc_pri = desc; @@ -236,21 +237,7 @@ struct irq_desc *irq_to_desc(unsigned int irq) desc->irq = irq; desc_pri->next = desc; - { - /* double check if some one mess up the list */ - struct irq_desc *desc; - int count = 0; - - desc = &sparse_irqs[0]; - while (desc) { - printk(KERN_DEBUG "1 found irq_desc for irq %d\n", desc->irq); - if (desc->next) - printk(KERN_DEBUG "1 found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq); - desc = desc->next; - count++; - } - printk(KERN_DEBUG "1 all preallocted %d\n", count); - } + printk(KERN_DEBUG "1 found new irq_desc for irq %d and pri will be irq %d\n", desc->irq, desc_pri->irq); return desc; } @@ -285,7 +272,7 @@ struct irq_desc *irq_to_desc(unsigned int irq) return NULL; } -struct irq_desc *__irq_to_desc(unsigned int irq) +struct irq_desc *irq_to_desc_alloc(unsigned int irq) { return irq_to_desc(irq); } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index c0b4d4d..6df4921 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -31,7 +31,7 @@ cpumask_t irq_default_affinity = CPU_MASK_ALL; */ void synchronize_irq(unsigned int irq) { - struct irq_desc *desc = __irq_to_desc(irq); + struct irq_desc *desc = irq_to_desc(irq); unsigned int status; if (!desc) @@ -145,7 +145,7 @@ void disable_irq_nosync(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return; @@ -174,7 +174,7 @@ void disable_irq(unsigned int irq) { struct irq_desc *desc; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return; @@ -218,7 +218,7 @@ void enable_irq(unsigned int irq) struct irq_desc *desc; unsigned long flags; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return; @@ -296,7 +296,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) struct irq_desc *desc; struct irqaction *action; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return 0; @@ -366,7 +366,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) int shared = 0; int ret; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return -EINVAL; @@ -527,7 +527,7 @@ void free_irq(unsigned int irq, void *dev_id) WARN_ON(in_interrupt()); - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return; @@ -644,7 +644,7 @@ int request_irq(unsigned int irq, irq_handler_t handler, if ((irqflags & IRQF_SHARED) && !dev_id) return -EINVAL; - desc = __irq_to_desc(irq); + desc = irq_to_desc(irq); if (!desc) return -EINVAL; -- cgit v1.1 From 67fb283e148e9bd761f73691d3173b6eab9ba8db Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:18 -0700 Subject: irq: separate sparse_irqs from sparse_irqs_free so later don't need compare with -1U Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 115 ++++++++++++++++++++++++++++------------------------ 1 file changed, 61 insertions(+), 54 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index d44e351..6d17439 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -112,6 +112,11 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) } } +#ifdef CONFIG_HAVE_SPARSE_IRQ +static struct irq_desc *sparse_irqs_free; +struct irq_desc *sparse_irqs; +#endif + static void __init init_work(void *data) { struct dyn_array *da = data; @@ -127,13 +132,16 @@ static void __init init_work(void *data) #endif } + /* init kstat_irqs, nr_cpu_ids is ready already */ + init_kstat_irqs(desc, *da->nr, nr_cpu_ids); + #ifdef CONFIG_HAVE_SPARSE_IRQ for (i = 1; i < *da->nr; i++) desc[i-1].next = &desc[i]; -#endif - /* init kstat_irqs, nr_cpu_ids is ready already */ - init_kstat_irqs(desc, *da->nr, nr_cpu_ids); + sparse_irqs_free = sparse_irqs; + sparse_irqs = NULL; +#endif } #ifdef CONFIG_HAVE_SPARSE_IRQ @@ -148,23 +156,17 @@ static int __init parse_nr_irq_desc(char *arg) early_param("nr_irq_desc", parse_nr_irq_desc); -struct irq_desc *sparse_irqs; DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); struct irq_desc *irq_to_desc(unsigned int irq) { struct irq_desc *desc; - BUG_ON(irq == -1U); - - desc = &sparse_irqs[0]; + desc = sparse_irqs; while (desc) { if (desc->irq == irq) return desc; - if (desc->irq == -1U) - return NULL; - desc = desc->next; } return NULL; @@ -174,21 +176,12 @@ struct irq_desc *irq_to_desc_alloc(unsigned int irq) struct irq_desc *desc, *desc_pri; int i; int count = 0; - unsigned long phys; - unsigned long total_bytes; - BUG_ON(irq == -1U); - - desc_pri = desc = &sparse_irqs[0]; + desc_pri = desc = sparse_irqs; while (desc) { if (desc->irq == irq) return desc; - if (desc->irq == -1U) { - desc->irq = irq; - printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); - return desc; - } desc_pri = desc; desc = desc->next; count++; @@ -197,48 +190,62 @@ struct irq_desc *irq_to_desc_alloc(unsigned int irq) /* * we run out of pre-allocate ones, allocate more */ - printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); - { - /* double check if some one mess up the list */ - struct irq_desc *desc; - int count = 0; - - desc = &sparse_irqs[0]; - while (desc) { - printk(KERN_DEBUG "found irq_desc for irq %d\n", desc->irq); - if (desc->next) - printk(KERN_DEBUG "found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq); - desc = desc->next; - count++; - } - printk(KERN_DEBUG "all preallocted %d\n", count); - } + if (!sparse_irqs_free) { + unsigned long phys; + unsigned long total_bytes; - total_bytes = sizeof(struct irq_desc) * nr_irq_desc; - if (after_bootmem) - desc = kzalloc(total_bytes, GFP_ATOMIC); - else - desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); + printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); - if (!desc) - panic("please boot with nr_irq_desc= %d\n", count * 2); + total_bytes = sizeof(struct irq_desc) * nr_irq_desc; + if (after_bootmem) + desc = kzalloc(total_bytes, GFP_ATOMIC); + else + desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); - phys = __pa(desc); - printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes); + if (!desc) + panic("please boot with nr_irq_desc= %d\n", count * 2); - for (i = 0; i < nr_irq_desc; i++) - init_one_irq_desc(&desc[i]); + phys = __pa(desc); + printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes); - for (i = 1; i < nr_irq_desc; i++) - desc[i-1].next = &desc[i]; + for (i = 0; i < nr_irq_desc; i++) + init_one_irq_desc(&desc[i]); - /* init kstat_irqs, nr_cpu_ids is ready already */ - init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids); + for (i = 1; i < nr_irq_desc; i++) + desc[i-1].next = &desc[i]; - desc->irq = irq; - desc_pri->next = desc; - printk(KERN_DEBUG "1 found new irq_desc for irq %d and pri will be irq %d\n", desc->irq, desc_pri->irq); + /* init kstat_irqs, nr_cpu_ids is ready already */ + init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids); + sparse_irqs_free = desc; + } + + desc = sparse_irqs_free; + sparse_irqs_free = sparse_irqs_free->next; + desc->next = NULL; + if (desc_pri) + desc_pri->next = desc; + else + sparse_irqs = desc; + desc->irq = irq; + printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); +#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG + { + /* dump the results */ + struct irq_desc *desc; + unsigned long phys; + unsigned long bytes = sizeof(struct irq_desc); + unsigned int irqx; + + printk(KERN_DEBUG "=========================== %d\n", irq); + printk(KERN_DEBUG "irq_desc dump after get that for %d\n", irq); + for_each_irq_desc(irqx, desc) { + phys = __pa(desc); + printk(KERN_DEBUG "irq_desc %d ==> [%#lx - %#lx]\n", irqx, phys, phys + bytes); + } + printk(KERN_DEBUG "===========================\n"); + } +#endif return desc; } #else -- cgit v1.1 From 8b8e8c1bf7275eca859fe551dfa484134eaf013b Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:23 -0700 Subject: x86: remove irqbalance in kernel for 32 bit This has been deprecated for years, the user space irqbalanced utility works better with numa, has configurable policies, etc... Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/manage.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 6df4921..ddc95686 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -86,8 +86,6 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) if (!desc->chip->set_affinity) return -EINVAL; - set_balance_irq_affinity(irq, cpumask); - #ifdef CONFIG_GENERIC_PENDING_IRQ if (desc->status & IRQ_MOVE_PCNTXT) { unsigned long flags; @@ -122,7 +120,6 @@ int irq_select_affinity(unsigned int irq) desc->affinity = mask; desc->chip->set_affinity(irq, mask); - set_balance_irq_affinity(irq, mask); return 0; } #endif -- cgit v1.1 From e955b5398b660a204854bdff059d050b44090879 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 19 Aug 2008 20:50:37 -0700 Subject: sparseirq: fix lockdep -tip testing found this lockdep splat: [ 0.000000] Initializing CPU#0 [ 0.000000] found new irq_desc for irq 0 [ 0.000000] INFO: trying to register non-static key. [ 0.000000] the code is fine but needs lockdep annotation. [ 0.000000] turning off the locking correctness validator. [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.27-rc3-tip-00191-g98ccb89-dirty #1 [ 0.000000] [] register_lock_class+0x3d2/0x400 [ 0.000000] [] ? mcount_call+0x5/0xa [ 0.000000] [] __lock_acquire+0x22a/0x5d0 [ 0.000000] [] ? mcount_call+0x5/0xa [ 0.000000] [] lock_acquire+0x71/0xa0 [ 0.000000] [] ? set_irq_chip+0x3f/0x90 [ 0.000000] [] _spin_lock_irqsave+0x58/0x90 [ 0.000000] [] ? set_irq_chip+0x3f/0x90 [ 0.000000] [] set_irq_chip+0x3f/0x90 [ 0.000000] [] ? handle_level_irq+0x0/0xe0 [ 0.000000] [] set_irq_chip_and_handler_name+0x1a/0x40 [ 0.000000] [] init_ISA_irqs+0x51/0xa0 [ 0.000000] [] pre_intr_init_hook+0x25/0x30 [ 0.000000] [] native_init_IRQ+0x13/0x370 [ 0.000000] [] ? lock_release+0xcc/0x1d0 [ 0.000000] [] ? mcount_call+0x5/0xa [ 0.000000] [] ? __mutex_unlock_slowpath+0x92/0x110 [ 0.000000] [] ? mutex_unlock+0xd/0x10 [ 0.000000] [] ? cpu_maps_update_done+0x12/0x20 [ 0.000000] [] ? register_cpu_notifier+0x23/0x30 [ 0.000000] [] init_IRQ+0xe/0x10 [ 0.000000] [] start_kernel+0x1c5/0x340 [ 0.000000] [] ? unknown_bootoption+0x0/0x210 [ 0.000000] [] i386_start_kernel+0x6b/0x80 [ 0.000000] ======================= [ 0.000000] found new irq_desc for irq 1 [ 0.000000] found new irq_desc for irq 2 [ 0.000000] found new irq_desc for irq 3 this: static void init_one_irq_desc(struct irq_desc *desc) { memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); #ifdef CONFIG_TRACE_IRQFLAGS lockdep_set_class(&desc->lock, &irq_desc_lock_class); #endif } should be unconditional. Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 6d17439..24c83a3 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -18,13 +18,10 @@ #include "internals.h" -#ifdef CONFIG_TRACE_IRQFLAGS - /* * lockdep: we want to handle all irq_desc locks as a single lock-class: */ static struct lock_class_key irq_desc_lock_class; -#endif /** * handle_bad_irq - handle spurious and unhandled irqs @@ -75,9 +72,7 @@ static struct irq_desc irq_desc_init = { static void init_one_irq_desc(struct irq_desc *desc) { memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); -#ifdef CONFIG_TRACE_IRQFLAGS lockdep_set_class(&desc->lock, &irq_desc_lock_class); -#endif } extern int after_bootmem; -- cgit v1.1 From e89eb43863c2d9f11a3bbe766766fe646e6c50d9 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 20 Aug 2008 20:46:25 -0700 Subject: x86: sparse_irq needs spin_lock in allocations Suresh Siddha noticed that we should have a spinlock around it. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 24c83a3..d638a91 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -107,6 +107,11 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) } } +/* + * Protect the sparse_irqs_free freelist: + */ +static DEFINE_SPINLOCK(sparse_irq_lock); + #ifdef CONFIG_HAVE_SPARSE_IRQ static struct irq_desc *sparse_irqs_free; struct irq_desc *sparse_irqs; @@ -166,11 +171,13 @@ struct irq_desc *irq_to_desc(unsigned int irq) } return NULL; } + struct irq_desc *irq_to_desc_alloc(unsigned int irq) { struct irq_desc *desc, *desc_pri; - int i; + unsigned long flags; int count = 0; + int i; desc_pri = desc = sparse_irqs; while (desc) { @@ -182,6 +189,7 @@ struct irq_desc *irq_to_desc_alloc(unsigned int irq) count++; } + spin_lock_irqsave(&sparse_irq_lock, flags); /* * we run out of pre-allocate ones, allocate more */ @@ -223,6 +231,9 @@ struct irq_desc *irq_to_desc_alloc(unsigned int irq) else sparse_irqs = desc; desc->irq = irq; + + spin_unlock_irqrestore(&sparse_irq_lock, flags); + printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); #ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG { -- cgit v1.1 From 8c464a4b23ca283b414022ebc77787f3c7040fa7 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 25 Aug 2008 12:41:19 -0700 Subject: sparseirq: move kstat_irqs from kstat to irq_desc - fix fix non-sparseirq architectures. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 21 ++++++++++++++++++++- kernel/irq/handle.c | 10 ++++++++++ 2 files changed, 30 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 9fc5e69..4ef555c 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -327,7 +327,11 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc) if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) @@ -368,7 +372,11 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif /* * If its disabled or no action available @@ -415,7 +423,11 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) goto out; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif /* * If its disabled or no action available @@ -479,8 +491,11 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc) mask_ack_irq(desc, irq); goto out_unlock; } - +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif /* Start handling the irq */ desc->chip->ack(irq); @@ -535,7 +550,11 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc) { irqreturn_t action_ret; +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif if (desc->chip->ack) desc->chip->ack(irq); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index d638a91..eae6937 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -34,7 +34,11 @@ void handle_bad_irq(unsigned int irq, struct irq_desc *desc) { print_irq_desc(irq, desc); +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif ack_bad_irq(irq); } @@ -401,7 +405,11 @@ unsigned int __do_IRQ(unsigned int irq) struct irqaction *action; unsigned int status; +#ifdef CONFIG_HAVE_DYN_ARRAY kstat_irqs_this_cpu(desc)++; +#else + kstat_irqs_this_cpu(irq)++; +#endif if (CHECK_IRQ_PER_CPU(desc->status)) { irqreturn_t action_ret; @@ -501,10 +509,12 @@ void early_init_irq_lock_class(void) } #endif +#ifdef CONFIG_HAVE_DYN_ARRAY unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) { struct irq_desc *desc = irq_to_desc(irq); return desc->kstat_irqs[cpu]; } +#endif EXPORT_SYMBOL(kstat_irqs_cpu); -- cgit v1.1 From 21056830c4e5c6735f1d49453398d7186ca4e8d7 Mon Sep 17 00:00:00 2001 From: Dean Nelson Date: Fri, 5 Sep 2008 09:10:40 -0500 Subject: irq: set_irq_chip() has redundant call to irq_to_desc() Extraneous call to irq_to_desc(). Signed-off-by: Dean Nelson Cc: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 4ef555c..570d1ea 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -102,7 +102,6 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) if (!chip) chip = &no_irq_chip; - desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock, flags); irq_chip_set_defaults(chip); desc->chip = chip; -- cgit v1.1 From 932775a4ab622e3c99bd59f14cc7d96722f79501 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Fri, 5 Sep 2008 18:02:15 -0700 Subject: x86: HPET_MSI change IRQ affinity in process context when it is disabled Change the IRQ affinity in the process context when the IRQ is disabled. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Shaohua Li Signed-off-by: Ingo Molnar --- kernel/irq/manage.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ddc95686..ad2ce72 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -87,10 +87,11 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) return -EINVAL; #ifdef CONFIG_GENERIC_PENDING_IRQ - if (desc->status & IRQ_MOVE_PCNTXT) { + if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { unsigned long flags; spin_lock_irqsave(&desc->lock, flags); + desc->affinity = cpumask; desc->chip->set_affinity(irq, cpumask); spin_unlock_irqrestore(&desc->lock, flags); } else -- cgit v1.1 From e00585bb7fc3d0b601181b765a254df7ff4ea59b Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 15 Sep 2008 01:53:50 -0700 Subject: irq: fix irqpoll && sparseirq Steven Noonan reported a boot hang when using irqpoll and CONFIG_HAVE_SPARSE_IRQ=y. The irqpoll loop needs to be updated to not iterate from 1 to nr_irqs but to iterate via for_each_irq_desc(). (in the former case desc can be NULL which crashes the box) Reported-by: Steven Noonan Tested-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index b5d9060..ec5a4be 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -90,14 +90,15 @@ static int misrouted_irq(int irq) { int i; int ok = 0; + struct irq_desc *desc; - for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc; + for_each_irq_desc(i, desc) { + if (!i) + continue; if (i == irq) /* Already tried */ continue; - desc = irq_to_desc(i); if (try_one_irq(i, desc)) ok = 1; } @@ -108,10 +109,14 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { int i; - for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_to_desc(i); + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { unsigned int status; + if (!i) + continue; + /* Racy but it doesn't matter */ status = desc->status; barrier(); @@ -278,7 +283,7 @@ static int __init irqfixup_setup(char *str) __setup("irqfixup", irqfixup_setup); module_param(irqfixup, int, 0644); -MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode 2: irqpoll mode"); +MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode, 2: irqpoll mode"); static int __init irqpoll_setup(char *str) { -- cgit v1.1 From 9d98598d2fc286c8dbcd0b681168639528428db0 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 19 Sep 2008 00:12:26 -0700 Subject: sparseirq: remove some debug print out Signed-off-by: Yinghai Lu Cc: Yinghai Lu Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 18 ------------------ 1 file changed, 18 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index eae6937..710db0e 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -238,24 +238,6 @@ struct irq_desc *irq_to_desc_alloc(unsigned int irq) spin_unlock_irqrestore(&sparse_irq_lock, flags); - printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); -#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG - { - /* dump the results */ - struct irq_desc *desc; - unsigned long phys; - unsigned long bytes = sizeof(struct irq_desc); - unsigned int irqx; - - printk(KERN_DEBUG "=========================== %d\n", irq); - printk(KERN_DEBUG "irq_desc dump after get that for %d\n", irq); - for_each_irq_desc(irqx, desc) { - phys = __pa(desc); - printk(KERN_DEBUG "irq_desc %d ==> [%#lx - %#lx]\n", irqx, phys, phys + bytes); - } - printk(KERN_DEBUG "===========================\n"); - } -#endif return desc; } #else -- cgit v1.1 From 2976fe20125587c944c8df48d991c38f0891fb28 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 18 Sep 2008 16:10:48 -0700 Subject: fix warning: "x86: sparse_irq needs spin_lock in allocations" caused by commit a532e19680ada3b8579b81e67e76d3ebd19c340f Author: Yinghai Lu Date: Wed Aug 20 20:46:25 2008 -0700 x86: sparse_irq needs spin_lock in allocations Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 710db0e..7f625fb 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -111,12 +111,11 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) } } +#ifdef CONFIG_HAVE_SPARSE_IRQ /* * Protect the sparse_irqs_free freelist: */ static DEFINE_SPINLOCK(sparse_irq_lock); - -#ifdef CONFIG_HAVE_SPARSE_IRQ static struct irq_desc *sparse_irqs_free; struct irq_desc *sparse_irqs; #endif -- cgit v1.1 From aac3f2b6f6e88827432c4050ac73552f24b19de1 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 24 Sep 2008 19:04:35 -0700 Subject: x86: fix typo in irq_desc array when SPARSE_IRQ is not used, should still use irq_desc->lock Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/handle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 7f625fb..fb6bdb6 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -253,7 +253,7 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { .chip = &no_irq_chip, .handle_irq = handle_bad_irq, .depth = 1, - .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock), + .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock), #ifdef CONFIG_SMP .affinity = CPU_MASK_ALL #endif -- cgit v1.1 From c6b7674f323622d86316bf7951ad9cae1ce24642 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 15 Oct 2008 14:31:29 +0200 Subject: genirq: use inline function for irq_to_desc For the non sparse irq case an inline function is perfectly fine. Signed-off-by: Thomas Gleixner --- kernel/irq/handle.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index fb6bdb6..c19896f 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -262,20 +262,6 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { #endif -#ifndef CONFIG_HAVE_SPARSE_IRQ -struct irq_desc *irq_to_desc(unsigned int irq) -{ - if (irq < nr_irqs) - return &irq_desc[irq]; - - return NULL; -} -struct irq_desc *irq_to_desc_alloc(unsigned int irq) -{ - return irq_to_desc(irq); -} -#endif - /* * What should we do if we get a hw irq event on an illegal vector? * Each architecture has to answer this themself. -- cgit v1.1 From 2cc21ef843d4fb7da122239b644a1f6f0aca60a6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 15 Oct 2008 14:16:55 +0200 Subject: genirq: remove sparse irq code This code is not ready, but we need to rip it out instead of rebasing as we would lose the APIC/IO_APIC unification otherwise. Signed-off-by: Thomas Gleixner --- kernel/irq/handle.c | 114 ---------------------------------------------------- 1 file changed, 114 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index c19896f..f837133 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -111,15 +111,6 @@ static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) } } -#ifdef CONFIG_HAVE_SPARSE_IRQ -/* - * Protect the sparse_irqs_free freelist: - */ -static DEFINE_SPINLOCK(sparse_irq_lock); -static struct irq_desc *sparse_irqs_free; -struct irq_desc *sparse_irqs; -#endif - static void __init init_work(void *data) { struct dyn_array *da = data; @@ -130,121 +121,16 @@ static void __init init_work(void *data) for (i = 0; i < *da->nr; i++) { init_one_irq_desc(&desc[i]); -#ifndef CONFIG_HAVE_SPARSE_IRQ desc[i].irq = i; -#endif } /* init kstat_irqs, nr_cpu_ids is ready already */ init_kstat_irqs(desc, *da->nr, nr_cpu_ids); - -#ifdef CONFIG_HAVE_SPARSE_IRQ - for (i = 1; i < *da->nr; i++) - desc[i-1].next = &desc[i]; - - sparse_irqs_free = sparse_irqs; - sparse_irqs = NULL; -#endif -} - -#ifdef CONFIG_HAVE_SPARSE_IRQ -static int nr_irq_desc = 32; - -static int __init parse_nr_irq_desc(char *arg) -{ - if (arg) - nr_irq_desc = simple_strtoul(arg, NULL, 0); - return 0; -} - -early_param("nr_irq_desc", parse_nr_irq_desc); - -DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); - -struct irq_desc *irq_to_desc(unsigned int irq) -{ - struct irq_desc *desc; - - desc = sparse_irqs; - while (desc) { - if (desc->irq == irq) - return desc; - - desc = desc->next; - } - return NULL; } -struct irq_desc *irq_to_desc_alloc(unsigned int irq) -{ - struct irq_desc *desc, *desc_pri; - unsigned long flags; - int count = 0; - int i; - - desc_pri = desc = sparse_irqs; - while (desc) { - if (desc->irq == irq) - return desc; - - desc_pri = desc; - desc = desc->next; - count++; - } - - spin_lock_irqsave(&sparse_irq_lock, flags); - /* - * we run out of pre-allocate ones, allocate more - */ - if (!sparse_irqs_free) { - unsigned long phys; - unsigned long total_bytes; - - printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); - - total_bytes = sizeof(struct irq_desc) * nr_irq_desc; - if (after_bootmem) - desc = kzalloc(total_bytes, GFP_ATOMIC); - else - desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); - - if (!desc) - panic("please boot with nr_irq_desc= %d\n", count * 2); - - phys = __pa(desc); - printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes); - - for (i = 0; i < nr_irq_desc; i++) - init_one_irq_desc(&desc[i]); - - for (i = 1; i < nr_irq_desc; i++) - desc[i-1].next = &desc[i]; - - /* init kstat_irqs, nr_cpu_ids is ready already */ - init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids); - - sparse_irqs_free = desc; - } - - desc = sparse_irqs_free; - sparse_irqs_free = sparse_irqs_free->next; - desc->next = NULL; - if (desc_pri) - desc_pri->next = desc; - else - sparse_irqs = desc; - desc->irq = irq; - - spin_unlock_irqrestore(&sparse_irq_lock, flags); - - return desc; -} -#else struct irq_desc *irq_desc; DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); -#endif - #else struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { -- cgit v1.1 From ee32c9732244bde4b9b59eeac2814c23e2b71f8d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 15 Oct 2008 14:34:09 +0200 Subject: genirq: remove irq_to_desc_alloc Remove the leftover of sparseirqs. Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 570d1ea..e6f73db 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -28,7 +28,7 @@ void dynamic_irq_init(unsigned int irq) unsigned long flags; /* first time to use this irq_desc */ - desc = irq_to_desc_alloc(irq); + desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; -- cgit v1.1 From d6c88a507ef0b6afdb013cba4e7804ba7324d99a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 15 Oct 2008 15:27:23 +0200 Subject: genirq: revert dynarray Revert the dynarray changes. They need more thought and polishing. Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 30 +++----------- kernel/irq/handle.c | 114 +++++----------------------------------------------- 2 files changed, 14 insertions(+), 130 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index e6f73db..d96d6f6 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -326,11 +326,7 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc) if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) @@ -371,11 +367,7 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); /* * If its disabled or no action available @@ -422,11 +414,7 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) goto out; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); /* * If its disabled or no action available @@ -490,11 +478,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc) mask_ack_irq(desc, irq); goto out_unlock; } -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); /* Start handling the irq */ desc->chip->ack(irq); @@ -549,11 +533,7 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc) { irqreturn_t action_ret; -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); if (desc->chip->ack) desc->chip->ack(irq); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index f837133..9fe86b3 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -18,11 +18,6 @@ #include "internals.h" -/* - * lockdep: we want to handle all irq_desc locks as a single lock-class: - */ -static struct lock_class_key irq_desc_lock_class; - /** * handle_bad_irq - handle spurious and unhandled irqs * @irq: the interrupt number @@ -30,15 +25,10 @@ static struct lock_class_key irq_desc_lock_class; * * Handles spurious and unhandled IRQ's. It also prints a debugmessage. */ -void -handle_bad_irq(unsigned int irq, struct irq_desc *desc) +void handle_bad_irq(unsigned int irq, struct irq_desc *desc) { print_irq_desc(irq, desc); -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); ack_bad_irq(irq); } @@ -59,80 +49,6 @@ handle_bad_irq(unsigned int irq, struct irq_desc *desc) int nr_irqs = NR_IRQS; EXPORT_SYMBOL_GPL(nr_irqs); -#ifdef CONFIG_HAVE_DYN_ARRAY -static struct irq_desc irq_desc_init = { - .irq = -1U, - .status = IRQ_DISABLED, - .chip = &no_irq_chip, - .handle_irq = handle_bad_irq, - .depth = 1, - .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock), -#ifdef CONFIG_SMP - .affinity = CPU_MASK_ALL -#endif -}; - - -static void init_one_irq_desc(struct irq_desc *desc) -{ - memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); - lockdep_set_class(&desc->lock, &irq_desc_lock_class); -} - -extern int after_bootmem; -extern void *__alloc_bootmem_nopanic(unsigned long size, - unsigned long align, - unsigned long goal); - -static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) -{ - unsigned long bytes, total_bytes; - char *ptr; - int i; - unsigned long phys; - - /* Compute how many bytes we need per irq and allocate them */ - bytes = nr * sizeof(unsigned int); - total_bytes = bytes * nr_desc; - if (after_bootmem) - ptr = kzalloc(total_bytes, GFP_ATOMIC); - else - ptr = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); - - if (!ptr) - panic(" can not allocate kstat_irqs\n"); - - phys = __pa(ptr); - printk(KERN_DEBUG "kstat_irqs ==> [%#lx - %#lx]\n", phys, phys + total_bytes); - - for (i = 0; i < nr_desc; i++) { - desc[i].kstat_irqs = (unsigned int *)ptr; - ptr += bytes; - } -} - -static void __init init_work(void *data) -{ - struct dyn_array *da = data; - int i; - struct irq_desc *desc; - - desc = *da->name; - - for (i = 0; i < *da->nr; i++) { - init_one_irq_desc(&desc[i]); - desc[i].irq = i; - } - - /* init kstat_irqs, nr_cpu_ids is ready already */ - init_kstat_irqs(desc, *da->nr, nr_cpu_ids); -} - -struct irq_desc *irq_desc; -DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); - -#else - struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { [0 ... NR_IRQS-1] = { .status = IRQ_DISABLED, @@ -146,8 +62,6 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { } }; -#endif - /* * What should we do if we get a hw irq event on an illegal vector? * Each architecture has to answer this themself. @@ -258,11 +172,8 @@ unsigned int __do_IRQ(unsigned int irq) struct irqaction *action; unsigned int status; -#ifdef CONFIG_HAVE_DYN_ARRAY - kstat_irqs_this_cpu(desc)++; -#else - kstat_irqs_this_cpu(irq)++; -#endif + kstat_incr_irqs_this_cpu(irq, desc); + if (CHECK_IRQ_PER_CPU(desc->status)) { irqreturn_t action_ret; @@ -351,23 +262,16 @@ out: #ifdef CONFIG_TRACE_IRQFLAGS +/* + * lockdep: we want to handle all irq_desc locks as a single lock-class: + */ +static struct lock_class_key irq_desc_lock_class; + void early_init_irq_lock_class(void) { -#ifndef CONFIG_HAVE_DYN_ARRAY int i; for (i = 0; i < nr_irqs; i++) lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class); -#endif } #endif - -#ifdef CONFIG_HAVE_DYN_ARRAY -unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) -{ - struct irq_desc *desc = irq_to_desc(irq); - return desc->kstat_irqs[cpu]; -} -#endif -EXPORT_SYMBOL(kstat_irqs_cpu); - -- cgit v1.1 From d3c60047bdb03199b93497ac40bd531315d43a86 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Oct 2008 09:55:00 +0200 Subject: genirq: cleanup the sparseirq modifications Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 43 +++++++++++++------------------------------ kernel/irq/handle.c | 3 +-- kernel/irq/manage.c | 38 +++++++++++++++++++++++--------------- kernel/irq/proc.c | 1 + kernel/irq/spurious.c | 18 ++++++++++-------- 5 files changed, 48 insertions(+), 55 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index d96d6f6..4895fde 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -24,11 +24,9 @@ */ void dynamic_irq_init(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - /* first time to use this irq_desc */ - desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; @@ -58,10 +56,9 @@ void dynamic_irq_init(unsigned int irq) */ void dynamic_irq_cleanup(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); return; @@ -90,10 +87,9 @@ void dynamic_irq_cleanup(unsigned int irq) */ int set_irq_chip(unsigned int irq, struct irq_chip *chip) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq); return -EINVAL; @@ -118,11 +114,10 @@ EXPORT_SYMBOL(set_irq_chip); */ int set_irq_type(unsigned int irq, unsigned int type) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; int ret = -ENXIO; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; @@ -147,10 +142,9 @@ EXPORT_SYMBOL(set_irq_type); */ int set_irq_data(unsigned int irq, void *data) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); @@ -173,10 +167,9 @@ EXPORT_SYMBOL(set_irq_data); */ int set_irq_msi(unsigned int irq, struct msi_desc *entry) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); @@ -200,10 +193,9 @@ int set_irq_msi(unsigned int irq, struct msi_desc *entry) */ int set_irq_chip_data(unsigned int irq, void *data) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install chip data for IRQ%d\n", irq); @@ -228,9 +220,8 @@ EXPORT_SYMBOL(set_irq_chip_data); */ static void default_enable(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); - desc = irq_to_desc(irq); desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED; } @@ -247,11 +238,9 @@ static void default_disable(unsigned int irq) */ static unsigned int default_startup(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); - desc = irq_to_desc(irq); desc->chip->enable(irq); - return 0; } @@ -260,9 +249,8 @@ static unsigned int default_startup(unsigned int irq) */ static void default_shutdown(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); - desc = irq_to_desc(irq); desc->chip->mask(irq); desc->status |= IRQ_MASKED; } @@ -550,10 +538,9 @@ void __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, const char *name) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to install type control for IRQ%d\n", irq); @@ -614,13 +601,11 @@ set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip, void __init set_irq_noprobe(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq); - return; } @@ -631,13 +616,11 @@ void __init set_irq_noprobe(unsigned int irq) void __init set_irq_probe(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) { printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq); - return; } diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 9fe86b3..a69368f 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -68,9 +68,8 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { */ static void ack_bad(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); - desc = irq_to_desc(irq); print_irq_desc(irq, desc); ack_bad_irq(irq); } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ad2ce72..c498a1b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -140,10 +140,9 @@ int irq_select_affinity(unsigned int irq) */ void disable_irq_nosync(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) return; @@ -170,9 +169,8 @@ EXPORT_SYMBOL(disable_irq_nosync); */ void disable_irq(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); - desc = irq_to_desc(irq); if (!desc) return; @@ -213,10 +211,9 @@ static void __enable_irq(struct irq_desc *desc, unsigned int irq) */ void enable_irq(unsigned int irq) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - desc = irq_to_desc(irq); if (!desc) return; @@ -291,10 +288,9 @@ EXPORT_SYMBOL(set_irq_wake); */ int can_request_irq(unsigned int irq, unsigned long irqflags) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; - desc = irq_to_desc(irq); if (!desc) return 0; @@ -355,16 +351,15 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, * Internal function to register an irqaction - typically used to * allocate special interrupts that are part of the architecture. */ -int setup_irq(unsigned int irq, struct irqaction *new) +static int +__setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new) { - struct irq_desc *desc; struct irqaction *old, **p; const char *old_name = NULL; unsigned long flags; int shared = 0; int ret; - desc = irq_to_desc(irq); if (!desc) return -EINVAL; @@ -504,6 +499,20 @@ mismatch: } /** + * setup_irq - setup an interrupt + * @irq: Interrupt line to setup + * @act: irqaction for the interrupt + * + * Used to statically setup interrupts in the early boot process. + */ +int setup_irq(unsigned int irq, struct irqaction *act) +{ + struct irq_desc *desc = irq_to_desc(irq); + + return __setup_irq(irq, desc, act); +} + +/** * free_irq - free an interrupt * @irq: Interrupt line to free * @dev_id: Device identity to free @@ -519,13 +528,12 @@ mismatch: */ void free_irq(unsigned int irq, void *dev_id) { - struct irq_desc *desc; + struct irq_desc *desc = irq_to_desc(irq); struct irqaction **p; unsigned long flags; WARN_ON(in_interrupt()); - desc = irq_to_desc(irq); if (!desc) return; @@ -624,8 +632,8 @@ int request_irq(unsigned int irq, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { struct irqaction *action; - int retval; struct irq_desc *desc; + int retval; #ifdef CONFIG_LOCKDEP /* @@ -662,7 +670,7 @@ int request_irq(unsigned int irq, irq_handler_t handler, action->next = NULL; action->dev_id = dev_id; - retval = setup_irq(irq, action); + retval = __setup_irq(irq, desc, action); if (retval) kfree(action); diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index bc0993d..fac014a 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -215,6 +215,7 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action) { if (action->dir) { struct irq_desc *desc = irq_to_desc(irq); + remove_proc_entry(action->dir->name, desc->dir); } } diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index ec5a4be..dd364c1 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -26,8 +26,7 @@ static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); static int try_one_irq(int irq, struct irq_desc *desc) { struct irqaction *action; - int ok = 0; - int work = 0; /* Did we do work for a real IRQ */ + int ok = 0, work = 0; spin_lock(&desc->lock); /* Already running on another processor */ @@ -88,9 +87,8 @@ static int try_one_irq(int irq, struct irq_desc *desc) static int misrouted_irq(int irq) { - int i; - int ok = 0; struct irq_desc *desc; + int i, ok = 0; for_each_irq_desc(i, desc) { if (!i) @@ -108,8 +106,8 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { - int i; struct irq_desc *desc; + int i; for_each_irq_desc(i, desc) { unsigned int status; @@ -126,7 +124,8 @@ static void poll_spurious_irqs(unsigned long dummy) try_one_irq(i, desc); } - mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); + mod_timer(&poll_spurious_irq_timer, + jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } /* @@ -177,7 +176,9 @@ report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) } } -static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) +static inline int +try_misrouted_irq(unsigned int irq, struct irq_desc *desc, + irqreturn_t action_ret) { struct irqaction *action; @@ -253,7 +254,8 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, desc->depth++; desc->chip->disable(irq); - mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); + mod_timer(&poll_spurious_irq_timer, + jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } desc->irqs_unhandled = 0; } -- cgit v1.1 From 10e580842ec8e53dddf62e1ab1871f4906477376 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Oct 2008 14:19:04 +0200 Subject: genirq: use iterators for irq_desc loops Use for_each_irq_desc[_reverse] for all the iteration loops. Signed-off-by: Thomas Gleixner --- kernel/irq/autoprobe.c | 45 ++++++++++++--------------------------------- kernel/irq/handle.c | 5 +++-- 2 files changed, 15 insertions(+), 35 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index b3a5549..0cbff18 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -30,19 +30,16 @@ static DEFINE_MUTEX(probing_active); unsigned long probe_irq_on(void) { struct irq_desc *desc; - unsigned long mask; - unsigned int i; + unsigned long mask = 0; + unsigned int status; + int i; mutex_lock(&probing_active); /* * something may have generated an irq long ago and we want to * flush such a longstanding irq before considering it as spurious. */ - for (i = nr_irqs-1; i > 0; i--) { - desc = irq_to_desc(i); - if (!desc) - continue; - + for_each_irq_desc_reverse(i, desc) { spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { /* @@ -70,11 +67,7 @@ unsigned long probe_irq_on(void) * (we must startup again here because if a longstanding irq * happened in the previous stage, it may have masked itself) */ - for (i = nr_irqs-1; i > 0; i--) { - desc = irq_to_desc(i); - if (!desc) - continue; - + for_each_irq_desc_reverse(i, desc) { spin_lock_irq(&desc->lock); if (!desc->action && !(desc->status & IRQ_NOPROBE)) { desc->status |= IRQ_AUTODETECT | IRQ_WAITING; @@ -92,13 +85,7 @@ unsigned long probe_irq_on(void) /* * Now filter out any obviously spurious interrupts */ - mask = 0; - for (i = 0; i < nr_irqs; i++) { - unsigned int status; - - desc = irq_to_desc(i); - if (!desc) - continue; + for_each_irq_desc(i, desc) { spin_lock_irq(&desc->lock); status = desc->status; @@ -132,16 +119,11 @@ EXPORT_SYMBOL(probe_irq_on); */ unsigned int probe_irq_mask(unsigned long val) { - unsigned int mask; + unsigned int status, mask = 0; + struct irq_desc *desc; int i; - mask = 0; - for (i = 0; i < nr_irqs; i++) { - struct irq_desc *desc = irq_to_desc(i); - unsigned int status; - - if (!desc) - continue; + for_each_irq_desc(i, desc) { spin_lock_irq(&desc->lock); status = desc->status; @@ -180,13 +162,10 @@ EXPORT_SYMBOL(probe_irq_mask); int probe_irq_off(unsigned long val) { int i, irq_found = 0, nr_irqs = 0; + struct irq_desc *desc; + unsigned int status; - for (i = 0; i < nr_irqs; i++) { - struct irq_desc *desc = irq_to_desc(i); - unsigned int status; - - if (!desc) - continue; + for_each_irq_desc(i, desc) { spin_lock_irq(&desc->lock); status = desc->status; diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index a69368f..c815b42 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -268,9 +268,10 @@ static struct lock_class_key irq_desc_lock_class; void early_init_irq_lock_class(void) { + struct irq_desc *desc; int i; - for (i = 0; i < nr_irqs; i++) - lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class); + for_each_irq_desc(i, desc) + lockdep_set_class(&desc->lock, &irq_desc_lock_class); } #endif -- cgit v1.1 From 63d659d556f145d33798b8ad19ced10c254fe445 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Oct 2008 15:33:18 +0200 Subject: genirq: fix name space collision of nr_irqs in autoprobe.c probe_irq_off() is disfunctional as the local nr_irqs is referenced instead of the global one for the for_each_irq_desc() iterator. Signed-off-by: Thomas Gleixner --- kernel/irq/autoprobe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index 0cbff18..cc0f732 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -161,7 +161,7 @@ EXPORT_SYMBOL(probe_irq_mask); */ int probe_irq_off(unsigned long val) { - int i, irq_found = 0, nr_irqs = 0; + int i, irq_found = 0, nr_of_irqs = 0; struct irq_desc *desc; unsigned int status; @@ -171,9 +171,9 @@ int probe_irq_off(unsigned long val) if (status & IRQ_AUTODETECT) { if (!(status & IRQ_WAITING)) { - if (!nr_irqs) + if (!nr_of_irqs) irq_found = i; - nr_irqs++; + nr_of_irqs++; } desc->status = status & ~IRQ_AUTODETECT; desc->chip->shutdown(i); @@ -182,7 +182,7 @@ int probe_irq_off(unsigned long val) } mutex_unlock(&probing_active); - if (nr_irqs > 1) + if (nr_of_irqs > 1) irq_found = -irq_found; return irq_found; -- cgit v1.1 From c851c8676bd7ae456e9b3af8e6bb2c434eddcc75 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Fri, 17 Oct 2008 18:17:46 +0800 Subject: sched: fix the wrong mask_len If NR_CPUS isn't a multiple of 32, we get a truncated string of sched domains by catting /proc/schedstat. This is caused by the wrong mask_len. This patch fixes it. Signed-off-by: Miao Xie Cc: Signed-off-by: Ingo Molnar --- kernel/sched_stats.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 8385d43..81365b3 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -9,7 +9,7 @@ static int show_schedstat(struct seq_file *seq, void *v) { int cpu; - int mask_len = NR_CPUS/32 * 9; + int mask_len = (NR_CPUS/32 + 1) * 9; char *mask_str = kmalloc(mask_len, GFP_KERNEL); if (mask_str == NULL) -- cgit v1.1 From b968905292eaa52b25abb7b3e6c0841dac9f03ae Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 17 Oct 2008 12:58:19 +0200 Subject: sched: fix the wrong mask_len, cleanup Clean up the division in show_schedstat(). Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_stats.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 81365b3..6757925 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -9,7 +9,7 @@ static int show_schedstat(struct seq_file *seq, void *v) { int cpu; - int mask_len = (NR_CPUS/32 + 1) * 9; + int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9; char *mask_str = kmalloc(mask_len, GFP_KERNEL); if (mask_str == NULL) -- cgit v1.1 From b0aa51b999c449e5e3f9faa1ee406e052d407fe7 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 17 Oct 2008 15:33:21 +0200 Subject: sched: minor fast-path overhead reduction Greetings, 103638d added a bit of avoidable overhead to the fast-path. Use sysctl_sched_min_granularity instead of sched_slice() to restrict buddy wakeups. Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 18fd171..6708493 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -747,7 +747,7 @@ pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) struct rq *rq = rq_of(cfs_rq); u64 pair_slice = rq->clock - cfs_rq->pair_start; - if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) { + if (!cfs_rq->next || pair_slice > sysctl_sched_min_granularity) { cfs_rq->pair_start = rq->clock; return se; } -- cgit v1.1 From 719254faa17ffedc87ba0fadb9b34e535c9758d5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 17 Oct 2008 09:59:47 +0200 Subject: NOHZ: unify the nohz function calls in irq_enter() We have two separate nohz function calls in irq_enter() for no good reason. Just call a single NOHZ function from irq_enter() and call the bits in the tick code. Signed-off-by: Thomas Gleixner --- kernel/softirq.c | 10 +++------- kernel/time/tick-sched.c | 13 ++++++++++++- 2 files changed, 15 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/softirq.c b/kernel/softirq.c index 37d67aa..d410014 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -265,16 +265,12 @@ asmlinkage void do_softirq(void) */ void irq_enter(void) { -#ifdef CONFIG_NO_HZ int cpu = smp_processor_id(); + if (idle_cpu(cpu) && !in_interrupt()) - tick_nohz_stop_idle(cpu); -#endif + tick_check_idle(cpu); + __irq_enter(); -#ifdef CONFIG_NO_HZ - if (idle_cpu(cpu)) - tick_nohz_update_jiffies(); -#endif } #ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index b711ffc..fdcf3f9 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -155,7 +155,7 @@ void tick_nohz_update_jiffies(void) touch_softlockup_watchdog(); } -void tick_nohz_stop_idle(int cpu) +static void tick_nohz_stop_idle(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); @@ -559,6 +559,17 @@ static inline void tick_nohz_switch_to_nohz(void) { } #endif /* NO_HZ */ /* + * Called from irq_enter to notify about the possible interruption of idle() + */ +void tick_check_idle(int cpu) +{ +#ifdef CONFIG_NO_HZ + tick_nohz_stop_idle(cpu); + tick_nohz_update_jiffies(); +#endif +} + +/* * High resolution timer specific code */ #ifdef CONFIG_HIGH_RES_TIMERS -- cgit v1.1 From c34bec5a44e9486597d78e7a686b2f9088a0564c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 17 Oct 2008 10:04:34 +0200 Subject: NOHZ: split tick_nohz_restart_sched_tick() Split out the clock event device reprogramming. Preparatory patch. Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.c | 49 ++++++++++++++++++++++++++---------------------- 1 file changed, 27 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index fdcf3f9..7aedf43 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -377,6 +377,32 @@ ktime_t tick_nohz_get_sleep_length(void) return ts->sleep_length; } +static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) +{ + hrtimer_cancel(&ts->sched_timer); + ts->sched_timer.expires = ts->idle_tick; + + while (1) { + /* Forward the time to expire in the future */ + hrtimer_forward(&ts->sched_timer, now, tick_period); + + if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { + hrtimer_start(&ts->sched_timer, + ts->sched_timer.expires, + HRTIMER_MODE_ABS); + /* Check, if the timer was already in the past */ + if (hrtimer_active(&ts->sched_timer)) + break; + } else { + if (!tick_program_event(ts->sched_timer.expires, 0)) + break; + } + /* Update jiffies and reread time */ + tick_do_update_jiffies64(now); + now = ktime_get(); + } +} + /** * tick_nohz_restart_sched_tick - restart the idle tick from the idle task * @@ -430,28 +456,7 @@ void tick_nohz_restart_sched_tick(void) */ ts->tick_stopped = 0; ts->idle_exittime = now; - hrtimer_cancel(&ts->sched_timer); - ts->sched_timer.expires = ts->idle_tick; - - while (1) { - /* Forward the time to expire in the future */ - hrtimer_forward(&ts->sched_timer, now, tick_period); - - if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { - hrtimer_start(&ts->sched_timer, - ts->sched_timer.expires, - HRTIMER_MODE_ABS); - /* Check, if the timer was already in the past */ - if (hrtimer_active(&ts->sched_timer)) - break; - } else { - if (!tick_program_event(ts->sched_timer.expires, 0)) - break; - } - /* Update jiffies and reread time */ - tick_do_update_jiffies64(now); - now = ktime_get(); - } + tick_nohz_restart(ts, now); local_irq_enable(); } -- cgit v1.1 From fb02fbc14d17837b4b7b02dbb36142c16a7bf208 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 17 Oct 2008 10:01:23 +0200 Subject: NOHZ: restart tick device from irq_enter() We did not restart the tick device from irq_enter() to avoid double reprogramming and extra events in the return immediate to idle case. But long lasting softirqs can lead to a situation where jiffies become stale: idle() tick stopped (reprogrammed to next pending timer) halt() interrupt jiffies updated from irq_enter() interrupt handler softirq function 1 runs 20ms softirq function 2 arms a 10ms timer with a stale jiffies value jiffies updated from irq_exit() timer wheel has now an already expired timer (the one added in function 2) timer fires and timer softirq runs This was discovered when debugging a timer problem which happend only when the ath5k driver is active. The debugging proved that there is a softirq function running for more than 20ms, which is a bug by itself. To solve this we restart the tick timer right from irq_enter(), but do not go through the other functions which are necessary to return from idle when need_resched() is set. Reported-by: Elias Oltmanns Signed-off-by: Thomas Gleixner Tested-by: Elias Oltmanns --- kernel/time/tick-broadcast.c | 13 +++++++++++++ kernel/time/tick-internal.h | 2 ++ kernel/time/tick-sched.c | 31 +++++++++++++++++++++++-------- 3 files changed, 38 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index cb01cd8..f98a1b7 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -384,6 +384,19 @@ int tick_resume_broadcast_oneshot(struct clock_event_device *bc) } /* + * Called from irq_enter() when idle was interrupted to reenable the + * per cpu device. + */ +void tick_check_oneshot_broadcast(int cpu) +{ + if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) { + struct tick_device *td = &per_cpu(tick_cpu_device, cpu); + + clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT); + } +} + +/* * Handle oneshot mode broadcasting */ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev) diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 4692487..b1c05bf 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -36,6 +36,7 @@ extern void tick_broadcast_switch_to_oneshot(void); extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup); extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc); extern int tick_broadcast_oneshot_active(void); +extern void tick_check_oneshot_broadcast(int cpu); # else /* BROADCAST */ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { @@ -45,6 +46,7 @@ static inline void tick_broadcast_oneshot_control(unsigned long reason) { } static inline void tick_broadcast_switch_to_oneshot(void) { } static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { } static inline int tick_broadcast_oneshot_active(void) { return 0; } +static inline void tick_check_oneshot_broadcast(int cpu) { } # endif /* !BROADCAST */ #else /* !ONESHOT */ diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7aedf43..0581c11 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -508,10 +508,6 @@ static void tick_nohz_handler(struct clock_event_device *dev) update_process_times(user_mode(regs)); profile_tick(CPU_PROFILING); - /* Do not restart, when we are in the idle loop */ - if (ts->tick_stopped) - return; - while (tick_nohz_reprogram(ts, now)) { now = ktime_get(); tick_do_update_jiffies64(now); @@ -557,6 +553,27 @@ static void tick_nohz_switch_to_nohz(void) smp_processor_id()); } +/* + * When NOHZ is enabled and the tick is stopped, we need to kick the + * tick timer from irq_enter() so that the jiffies update is kept + * alive during long running softirqs. That's ugly as hell, but + * correctness is key even if we need to fix the offending softirq in + * the first place. + * + * Note, this is different to tick_nohz_restart. We just kick the + * timer and do not touch the other magic bits which need to be done + * when idle is left. + */ +static void tick_nohz_kick_tick(int cpu) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + + if (!ts->tick_stopped) + return; + + tick_nohz_restart(ts, ktime_get()); +} + #else static inline void tick_nohz_switch_to_nohz(void) { } @@ -568,9 +585,11 @@ static inline void tick_nohz_switch_to_nohz(void) { } */ void tick_check_idle(int cpu) { + tick_check_oneshot_broadcast(cpu); #ifdef CONFIG_NO_HZ tick_nohz_stop_idle(cpu); tick_nohz_update_jiffies(); + tick_nohz_kick_tick(cpu); #endif } @@ -627,10 +646,6 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer) profile_tick(CPU_PROFILING); } - /* Do not restart, when we are in the idle loop */ - if (ts->tick_stopped) - return HRTIMER_NORESTART; - hrtimer_forward(timer, now, tick_period); return HRTIMER_RESTART; -- cgit v1.1 From e67ef25a35b949561a9bd77693523ec94ab4a278 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Sep 2008 23:50:23 +0200 Subject: timer_list: print real timer address The current timer_list output prints the address of the on stack copy of the active hrtimer instead of the hrtimer itself. Print the address of the real timer instead. Signed-off-by: Thomas Gleixner --- kernel/time/timer_list.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index a40e20f..ec9ea6c 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -47,13 +47,14 @@ static void print_name_offset(struct seq_file *m, void *sym) } static void -print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now) +print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, + int idx, u64 now) { #ifdef CONFIG_TIMER_STATS char tmp[TASK_COMM_LEN + 1]; #endif SEQ_printf(m, " #%d: ", idx); - print_name_offset(m, timer); + print_name_offset(m, taddr); SEQ_printf(m, ", "); print_name_offset(m, timer->function); SEQ_printf(m, ", S:%02lx", timer->state); @@ -99,7 +100,7 @@ next_one: tmp = *timer; spin_unlock_irqrestore(&base->cpu_base->lock, flags); - print_timer(m, &tmp, i, now); + print_timer(m, timer, &tmp, i, now); next++; goto next_one; } -- cgit v1.1 From c5b77a3d3a716a5c61a1999d7f2a78e9c39fd1b0 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 29 Sep 2008 17:31:41 +0200 Subject: timer_list: print cpu number of clockevents device The per cpu clock events device output of timer_list lacks an association of the device to the cpu which is annoying when looking at the output of /proc/timer_list from a 128 way system. Add the CPU number info and mark the broadcast device in the device list printout. Signed-off-by: Thomas Gleixner --- kernel/time/timer_list.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index ec9ea6c..5479c6e 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -184,12 +184,16 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) #ifdef CONFIG_GENERIC_CLOCKEVENTS static void -print_tickdevice(struct seq_file *m, struct tick_device *td) +print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) { struct clock_event_device *dev = td->evtdev; SEQ_printf(m, "\n"); SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); + if (cpu < 0) + SEQ_printf(m, "Broadcast device\n"); + else + SEQ_printf(m, "Per CPU device: %d\n", cpu); SEQ_printf(m, "Clock Event Device: "); if (!dev) { @@ -223,7 +227,7 @@ static void timer_list_show_tickdevices(struct seq_file *m) int cpu; #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST - print_tickdevice(m, tick_get_broadcast_device()); + print_tickdevice(m, tick_get_broadcast_device(), -1); SEQ_printf(m, "tick_broadcast_mask: %08lx\n", tick_get_broadcast_mask()->bits[0]); #ifdef CONFIG_TICK_ONESHOT @@ -233,7 +237,7 @@ static void timer_list_show_tickdevices(struct seq_file *m) SEQ_printf(m, "\n"); #endif for_each_online_cpu(cpu) - print_tickdevice(m, tick_get_device(cpu)); + print_tickdevice(m, tick_get_device(cpu), cpu); SEQ_printf(m, "\n"); } #else -- cgit v1.1 From 870e2a284567714335d125c390366dce882d726f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 29 Sep 2008 17:41:55 +0200 Subject: timer_list: add base address to clock base The base address of a (per cpu) clock base is a useful debug info. Add it and bump the version number of timer_lists. Signed-off-by: Thomas Gleixner --- kernel/time/timer_list.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 5479c6e..f642691 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -110,6 +110,7 @@ next_one: static void print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) { + SEQ_printf(m, " .base: %p\n", base); SEQ_printf(m, " .index: %d\n", base->index); SEQ_printf(m, " .resolution: %Lu nsecs\n", @@ -249,7 +250,7 @@ static int timer_list_show(struct seq_file *m, void *v) u64 now = ktime_to_ns(ktime_get()); int cpu; - SEQ_printf(m, "Timer List Version: v0.3\n"); + SEQ_printf(m, "Timer List Version: v0.4\n"); SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); -- cgit v1.1 From e1dd7bc58578ebfcaba989608017fe5156c29c86 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 20 Oct 2008 13:33:36 +0200 Subject: hrtimers: fix docbook comments hrtimer_start() and hrtimer_start_range_ns() handle relative and absolute timers. Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 51ee90b..00e6f0a 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -946,7 +946,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) } /** - * hrtimer_start_range_ns - (re)start an relative timer on the current CPU + * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU * @timer: the timer to be added * @tim: expiry time * @delta_ns: "slack" range for the timer @@ -1022,7 +1022,7 @@ hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_n EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); /** - * hrtimer_start - (re)start an relative timer on the current CPU + * hrtimer_start - (re)start an hrtimer on the current CPU * @timer: the timer to be added * @tim: expiry time * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) -- cgit v1.1 From 643bdf68f92a8516574ed7ca3713f9334c331b8d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 20 Oct 2008 13:38:11 +0200 Subject: hrtimers: simplify hrtimer_peek_ahead_timers() Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 00e6f0a..4fc4141 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1394,22 +1394,16 @@ void hrtimer_interrupt(struct clock_event_device *dev) */ void hrtimer_peek_ahead_timers(void) { - unsigned long flags; struct tick_device *td; - struct clock_event_device *dev; + unsigned long flags; if (!hrtimer_hres_active()) return; local_irq_save(flags); td = &__get_cpu_var(tick_cpu_device); - if (!td) - goto out; - dev = td->evtdev; - if (!dev) - goto out; - hrtimer_interrupt(dev); -out: + if (td && td->evtdev) + hrtimer_interrupt(td->evtdev); local_irq_restore(flags); } -- cgit v1.1 From ffda12a17a324103e9900fa1035309811eecbfe5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 17 Oct 2008 19:27:02 +0200 Subject: sched: optimize group load balancer I noticed that tg_shares_up() unconditionally takes rq-locks for all cpus in the sched_domain. This hurts. We need the rq-locks whenever we change the weight of the per-cpu group sched entities. To allevate this a little, only change the weight when the new weight is at least shares_thresh away from the old value. This avoids the rq-lock for the top level entries, since those will never be re-weighted, and fuzzes the lower level entries a little to gain performance in semi-stable situations. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 45 +++++++++++++++++++++++++-------------------- kernel/sysctl.c | 10 ++++++++++ 2 files changed, 35 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index c530b84..11ca390 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -818,6 +818,13 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32; unsigned int sysctl_sched_shares_ratelimit = 250000; /* + * Inject some fuzzyness into changing the per-cpu group shares + * this avoids remote rq-locks at the expense of fairness. + * default: 4 + */ +unsigned int sysctl_sched_shares_thresh = 4; + +/* * period over which we measure -rt task cpu usage in us. * default: 1s */ @@ -1453,8 +1460,8 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares); * Calculate and set the cpu's group shares. */ static void -__update_group_shares_cpu(struct task_group *tg, int cpu, - unsigned long sd_shares, unsigned long sd_rq_weight) +update_group_shares_cpu(struct task_group *tg, int cpu, + unsigned long sd_shares, unsigned long sd_rq_weight) { int boost = 0; unsigned long shares; @@ -1485,19 +1492,23 @@ __update_group_shares_cpu(struct task_group *tg, int cpu, * */ shares = (sd_shares * rq_weight) / (sd_rq_weight + 1); + shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); - /* - * record the actual number of shares, not the boosted amount. - */ - tg->cfs_rq[cpu]->shares = boost ? 0 : shares; - tg->cfs_rq[cpu]->rq_weight = rq_weight; + if (abs(shares - tg->se[cpu]->load.weight) > + sysctl_sched_shares_thresh) { + struct rq *rq = cpu_rq(cpu); + unsigned long flags; - if (shares < MIN_SHARES) - shares = MIN_SHARES; - else if (shares > MAX_SHARES) - shares = MAX_SHARES; + spin_lock_irqsave(&rq->lock, flags); + /* + * record the actual number of shares, not the boosted amount. + */ + tg->cfs_rq[cpu]->shares = boost ? 0 : shares; + tg->cfs_rq[cpu]->rq_weight = rq_weight; - __set_se_shares(tg->se[cpu], shares); + __set_se_shares(tg->se[cpu], shares); + spin_unlock_irqrestore(&rq->lock, flags); + } } /* @@ -1526,14 +1537,8 @@ static int tg_shares_up(struct task_group *tg, void *data) if (!rq_weight) rq_weight = cpus_weight(sd->span) * NICE_0_LOAD; - for_each_cpu_mask(i, sd->span) { - struct rq *rq = cpu_rq(i); - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - __update_group_shares_cpu(tg, i, shares, rq_weight); - spin_unlock_irqrestore(&rq->lock, flags); - } + for_each_cpu_mask(i, sd->span) + update_group_shares_cpu(tg, i, shares, rq_weight); return 0; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 617d41e..3d804f4 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -276,6 +276,16 @@ static struct ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, + .procname = "sched_shares_thresh", + .data = &sysctl_sched_shares_thresh, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "sched_child_runs_first", .data = &sysctl_sched_child_runs_first, .maxlen = sizeof(unsigned int), -- cgit v1.1 From a4c2f00f5cb848af7a8c816426b413c8e41834df Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 17 Oct 2008 19:27:03 +0200 Subject: sched: fair scheduler should not resched rt tasks With use of ftrace Steven noticed that some RT tasks got rescheduled due to sched_fair interaction. What happens is that we reprogram the hrtick from enqueue/dequeue_fair_task() because that can change nr_running, and thus a current tasks ideal runtime. However, its possible the current task isn't a fair_sched_class task, and thus doesn't have a hrtick set to change. Fix this by wrapping those hrtick_start_fair() calls in a hrtick_update() function, which will check for the right conditions. Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6708493..0c4bcac 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -73,6 +73,8 @@ unsigned int sysctl_sched_wakeup_granularity = 5000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; +static const struct sched_class fair_sched_class; + /************************************************************** * CFS operations on generic schedulable entities: */ @@ -848,11 +850,31 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p) hrtick_start(rq, delta); } } + +/* + * called from enqueue/dequeue and updates the hrtick when the + * current task is from our class and nr_running is low enough + * to matter. + */ +static void hrtick_update(struct rq *rq) +{ + struct task_struct *curr = rq->curr; + + if (curr->sched_class != &fair_sched_class) + return; + + if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency) + hrtick_start_fair(rq, curr); +} #else /* !CONFIG_SCHED_HRTICK */ static inline void hrtick_start_fair(struct rq *rq, struct task_struct *p) { } + +static inline void hrtick_update(struct rq *rq) +{ +} #endif /* @@ -873,7 +895,7 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) wakeup = 1; } - hrtick_start_fair(rq, rq->curr); + hrtick_update(rq); } /* @@ -895,7 +917,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) sleep = 1; } - hrtick_start_fair(rq, rq->curr); + hrtick_update(rq); } /* @@ -1001,8 +1023,6 @@ static inline int wake_idle(int cpu, struct task_struct *p) #ifdef CONFIG_SMP -static const struct sched_class fair_sched_class; - #ifdef CONFIG_FAIR_GROUP_SCHED /* * effective_load() calculates the load change as seen from the root_task_group -- cgit v1.1 From f9c0b0950d5fd8c8c5af39bc061f27ea8fddcac3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 17 Oct 2008 19:27:04 +0200 Subject: sched: revert back to per-rq vruntime Vatsa rightly points out that having the runqueue weight in the vruntime calculations can cause unfairness in the face of task joins/leaves. Suppose: dv = dt * rw / w Then take 10 tasks t_n, each of similar weight. If the first will run 1 then its vruntime will increase by 10. Now, if the next 8 tasks leave after having run their 1, then the last task will get a vruntime increase of 2 after having run 1. Which will leave us with 2 tasks of equal weight and equal runtime, of which one will not be scheduled for 8/2=4 units of time. Ergo, we cannot do that and must use: dv = dt / w. This means we cannot have a global vruntime based on effective priority, but must instead go back to the vruntime per rq model we started out with. This patch was lightly tested by doing starting while loops on each nice level and observing their execution time, and a simple group scenario of 1:2:3 pinned to a single cpu. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 0c4bcac..a0aa38b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -336,7 +336,7 @@ int sched_nr_latency_handler(struct ctl_table *table, int write, #endif /* - * delta *= w / rw + * delta *= P[w / rw] */ static inline unsigned long calc_delta_weight(unsigned long delta, struct sched_entity *se) @@ -350,15 +350,13 @@ calc_delta_weight(unsigned long delta, struct sched_entity *se) } /* - * delta *= rw / w + * delta /= w */ static inline unsigned long calc_delta_fair(unsigned long delta, struct sched_entity *se) { - for_each_sched_entity(se) { - delta = calc_delta_mine(delta, - cfs_rq_of(se)->load.weight, &se->load); - } + if (unlikely(se->load.weight != NICE_0_LOAD)) + delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load); return delta; } @@ -388,26 +386,26 @@ static u64 __sched_period(unsigned long nr_running) * We calculate the wall-time slice from the period by taking a part * proportional to the weight. * - * s = p*w/rw + * s = p*P[w/rw] */ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - return calc_delta_weight(__sched_period(cfs_rq->nr_running), se); + unsigned long nr_running = cfs_rq->nr_running; + + if (unlikely(!se->on_rq)) + nr_running++; + + return calc_delta_weight(__sched_period(nr_running), se); } /* * We calculate the vruntime slice of a to be inserted task * - * vs = s*rw/w = p + * vs = s/w */ -static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se) +static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - unsigned long nr_running = cfs_rq->nr_running; - - if (!se->on_rq) - nr_running++; - - return __sched_period(nr_running); + return calc_delta_fair(sched_slice(cfs_rq, se), se); } /* @@ -629,7 +627,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) * stays open at the end. */ if (initial && sched_feat(START_DEBIT)) - vruntime += sched_vslice_add(cfs_rq, se); + vruntime += sched_vslice(cfs_rq, se); if (!initial) { /* sleeps upto a single latency don't count. */ -- cgit v1.1 From 0c4b83da58ec2e96ce9c44c211d6eac5f9dae478 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 20 Oct 2008 14:27:43 +0200 Subject: sched: disable the hrtick for now David Miller reported that hrtick update overhead has tripled the wakeup overhead on Sparc64. That is too much - disable the HRTICK feature for now by default, until a faster implementation is found. Reported-by: David Miller Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_features.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 7c9e8f4..fda0162 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -5,7 +5,7 @@ SCHED_FEAT(START_DEBIT, 1) SCHED_FEAT(AFFINE_WAKEUPS, 1) SCHED_FEAT(CACHE_HOT_BUDDY, 1) SCHED_FEAT(SYNC_WAKEUPS, 1) -SCHED_FEAT(HRTICK, 1) +SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) SCHED_FEAT(ASYM_GRAN, 1) SCHED_FEAT(LB_BIAS, 1) -- cgit v1.1 From af936a1606246a10c145feac3770f6287f483f02 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Sat, 18 Oct 2008 20:26:53 -0700 Subject: vmscan: unevictable LRU scan sysctl This patch adds a function to scan individual or all zones' unevictable lists and move any pages that have become evictable onto the respective zone's inactive list, where shrink_inactive_list() will deal with them. Adds sysctl to scan all nodes, and per node attributes to individual nodes' zones. Kosaki: If evictable page found in unevictable lru when write /proc/sys/vm/scan_unevictable_pages, print filename and file offset of these pages. [akpm@linux-foundation.org: fix one CONFIG_MMU=n build error] [kosaki.motohiro@jp.fujitsu.com: adapt vmscan-unevictable-lru-scan-sysctl.patch to new sysfs API] Signed-off-by: Lee Schermerhorn Signed-off-by: Rik van Riel Signed-off-by: KOSAKI Motohiro Signed-off-by: KOSAKI Motohiro Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 617d41e..b3cc739 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -833,6 +833,16 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif +#ifdef CONFIG_UNEVICTABLE_LRU + { + .ctl_name = CTL_UNNUMBERED, + .procname = "scan_unevictable_pages", + .data = &scan_unevictable_pages, + .maxlen = sizeof(scan_unevictable_pages), + .mode = 0644, + .proc_handler = &scan_unevictable_handler, + }, +#endif /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt -- cgit v1.1 From 8174f1503f4bf7e9a14b3fbbfdb30c6be6e29f77 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:19 -0700 Subject: container freezer: make refrigerator always available Now that the TIF_FREEZE flag is available in all architectures, extract the refrigerator() and freeze_task() from kernel/power/process.c and make it available to all. The refrigerator() can now be used in a control group subsystem implementing a control group freezer. Signed-off-by: Cedric Le Goater Signed-off-by: Matt Helsley Acked-by: Serge E. Hallyn Tested-by: Matt Helsley Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/Makefile | 1 + kernel/freezer.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++ kernel/power/Kconfig | 3 ++ kernel/power/process.c | 116 ---------------------------------------------- 4 files changed, 126 insertions(+), 116 deletions(-) create mode 100644 kernel/freezer.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 4e1d7df..e8194d1 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -24,6 +24,7 @@ CFLAGS_REMOVE_sched_clock.o = -pg CFLAGS_REMOVE_sched.o = -mno-spe -pg endif +obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o diff --git a/kernel/freezer.c b/kernel/freezer.c new file mode 100644 index 0000000..cb0931f --- /dev/null +++ b/kernel/freezer.c @@ -0,0 +1,122 @@ +/* + * kernel/freezer.c - Function to freeze a process + * + * Originally from kernel/power/process.c + */ + +#include +#include +#include +#include +#include + +/* + * freezing is complete, mark current process as frozen + */ +static inline void frozen_process(void) +{ + if (!unlikely(current->flags & PF_NOFREEZE)) { + current->flags |= PF_FROZEN; + wmb(); + } + clear_freeze_flag(current); +} + +/* Refrigerator is place where frozen processes are stored :-). */ +void refrigerator(void) +{ + /* Hmm, should we be allowed to suspend when there are realtime + processes around? */ + long save; + + task_lock(current); + if (freezing(current)) { + frozen_process(); + task_unlock(current); + } else { + task_unlock(current); + return; + } + save = current->state; + pr_debug("%s entered refrigerator\n", current->comm); + + spin_lock_irq(¤t->sighand->siglock); + recalc_sigpending(); /* We sent fake signal, clean it up */ + spin_unlock_irq(¤t->sighand->siglock); + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!frozen(current)) + break; + schedule(); + } + pr_debug("%s left refrigerator\n", current->comm); + __set_current_state(save); +} +EXPORT_SYMBOL(refrigerator); + +static void fake_signal_wake_up(struct task_struct *p) +{ + unsigned long flags; + + spin_lock_irqsave(&p->sighand->siglock, flags); + signal_wake_up(p, 0); + spin_unlock_irqrestore(&p->sighand->siglock, flags); +} + +/** + * freeze_task - send a freeze request to given task + * @p: task to send the request to + * @sig_only: if set, the request will only be sent if the task has the + * PF_FREEZER_NOSIG flag unset + * Return value: 'false', if @sig_only is set and the task has + * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise + * + * The freeze request is sent by setting the tasks's TIF_FREEZE flag and + * either sending a fake signal to it or waking it up, depending on whether + * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task + * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its + * TIF_FREEZE flag will not be set. + */ +bool freeze_task(struct task_struct *p, bool sig_only) +{ + /* + * We first check if the task is freezing and next if it has already + * been frozen to avoid the race with frozen_process() which first marks + * the task as frozen and next clears its TIF_FREEZE. + */ + if (!freezing(p)) { + rmb(); + if (frozen(p)) + return false; + + if (!sig_only || should_send_signal(p)) + set_freeze_flag(p); + else + return false; + } + + if (should_send_signal(p)) { + if (!signal_pending(p)) + fake_signal_wake_up(p); + } else if (sig_only) { + return false; + } else { + wake_up_state(p, TASK_INTERRUPTIBLE); + } + + return true; +} + +void cancel_freezing(struct task_struct *p) +{ + unsigned long flags; + + if (freezing(p)) { + pr_debug(" clean up: %s\n", p->comm); + clear_freeze_flag(p); + spin_lock_irqsave(&p->sighand->siglock, flags); + recalc_sigpending_and_wake(p); + spin_unlock_irqrestore(&p->sighand->siglock, flags); + } +} diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index dcd165f..ebdd7f5 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -85,6 +85,9 @@ config PM_SLEEP depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y +config FREEZER + def_bool PM_SLEEP + config SUSPEND bool "Suspend to RAM and standby" depends on PM && ARCH_SUSPEND_POSSIBLE diff --git a/kernel/power/process.c b/kernel/power/process.c index 278946a..444cea8 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -28,121 +28,6 @@ static inline int freezeable(struct task_struct * p) return 1; } -/* - * freezing is complete, mark current process as frozen - */ -static inline void frozen_process(void) -{ - if (!unlikely(current->flags & PF_NOFREEZE)) { - current->flags |= PF_FROZEN; - wmb(); - } - clear_freeze_flag(current); -} - -/* Refrigerator is place where frozen processes are stored :-). */ -void refrigerator(void) -{ - /* Hmm, should we be allowed to suspend when there are realtime - processes around? */ - long save; - - task_lock(current); - if (freezing(current)) { - frozen_process(); - task_unlock(current); - } else { - task_unlock(current); - return; - } - save = current->state; - pr_debug("%s entered refrigerator\n", current->comm); - - spin_lock_irq(¤t->sighand->siglock); - recalc_sigpending(); /* We sent fake signal, clean it up */ - spin_unlock_irq(¤t->sighand->siglock); - - for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!frozen(current)) - break; - schedule(); - } - pr_debug("%s left refrigerator\n", current->comm); - __set_current_state(save); -} - -static void fake_signal_wake_up(struct task_struct *p) -{ - unsigned long flags; - - spin_lock_irqsave(&p->sighand->siglock, flags); - signal_wake_up(p, 0); - spin_unlock_irqrestore(&p->sighand->siglock, flags); -} - -static inline bool should_send_signal(struct task_struct *p) -{ - return !(p->flags & PF_FREEZER_NOSIG); -} - -/** - * freeze_task - send a freeze request to given task - * @p: task to send the request to - * @sig_only: if set, the request will only be sent if the task has the - * PF_FREEZER_NOSIG flag unset - * Return value: 'false', if @sig_only is set and the task has - * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise - * - * The freeze request is sent by setting the tasks's TIF_FREEZE flag and - * either sending a fake signal to it or waking it up, depending on whether - * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task - * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its - * TIF_FREEZE flag will not be set. - */ -static bool freeze_task(struct task_struct *p, bool sig_only) -{ - /* - * We first check if the task is freezing and next if it has already - * been frozen to avoid the race with frozen_process() which first marks - * the task as frozen and next clears its TIF_FREEZE. - */ - if (!freezing(p)) { - rmb(); - if (frozen(p)) - return false; - - if (!sig_only || should_send_signal(p)) - set_freeze_flag(p); - else - return false; - } - - if (should_send_signal(p)) { - if (!signal_pending(p)) - fake_signal_wake_up(p); - } else if (sig_only) { - return false; - } else { - wake_up_state(p, TASK_INTERRUPTIBLE); - } - - return true; -} - -static void cancel_freezing(struct task_struct *p) -{ - unsigned long flags; - - if (freezing(p)) { - pr_debug(" clean up: %s\n", p->comm); - clear_freeze_flag(p); - spin_lock_irqsave(&p->sighand->siglock, flags); - recalc_sigpending_and_wake(p); - spin_unlock_irqrestore(&p->sighand->siglock, flags); - } -} - static int try_to_freeze_tasks(bool sig_only) { struct task_struct *g, *p; @@ -264,4 +149,3 @@ void thaw_processes(void) printk("done.\n"); } -EXPORT_SYMBOL(refrigerator); -- cgit v1.1 From dc52ddc0e6f45b04780b26fc0813509f8e798c42 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:21 -0700 Subject: container freezer: implement freezer cgroup subsystem This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater Signed-off-by: Matt Helsley Acked-by: Serge E. Hallyn Tested-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/Kconfig.freezer | 2 + kernel/Makefile | 1 + kernel/cgroup_freezer.c | 366 ++++++++++++++++++++++++++++++++++++++++++++++++ kernel/freezer.c | 32 +++++ kernel/power/Kconfig | 3 - 5 files changed, 401 insertions(+), 3 deletions(-) create mode 100644 kernel/Kconfig.freezer create mode 100644 kernel/cgroup_freezer.c (limited to 'kernel') diff --git a/kernel/Kconfig.freezer b/kernel/Kconfig.freezer new file mode 100644 index 0000000..a3bb4cb --- /dev/null +++ b/kernel/Kconfig.freezer @@ -0,0 +1,2 @@ +config FREEZER + def_bool PM_SLEEP || CGROUP_FREEZER diff --git a/kernel/Makefile b/kernel/Makefile index e8194d1..066550a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o +obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c new file mode 100644 index 0000000..b08722d --- /dev/null +++ b/kernel/cgroup_freezer.c @@ -0,0 +1,366 @@ +/* + * cgroup_freezer.c - control group freezer subsystem + * + * Copyright IBM Corporation, 2007 + * + * Author : Cedric Le Goater + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include +#include +#include +#include +#include +#include + +enum freezer_state { + STATE_RUNNING = 0, + STATE_FREEZING, + STATE_FROZEN, +}; + +struct freezer { + struct cgroup_subsys_state css; + enum freezer_state state; + spinlock_t lock; /* protects _writes_ to state */ +}; + +static inline struct freezer *cgroup_freezer( + struct cgroup *cgroup) +{ + return container_of( + cgroup_subsys_state(cgroup, freezer_subsys_id), + struct freezer, css); +} + +static inline struct freezer *task_freezer(struct task_struct *task) +{ + return container_of(task_subsys_state(task, freezer_subsys_id), + struct freezer, css); +} + +int cgroup_frozen(struct task_struct *task) +{ + struct freezer *freezer; + enum freezer_state state; + + task_lock(task); + freezer = task_freezer(task); + state = freezer->state; + task_unlock(task); + + return state == STATE_FROZEN; +} + +/* + * cgroups_write_string() limits the size of freezer state strings to + * CGROUP_LOCAL_BUFFER_SIZE + */ +static const char *freezer_state_strs[] = { + "RUNNING", + "FREEZING", + "FROZEN", +}; + +/* + * State diagram + * Transitions are caused by userspace writes to the freezer.state file. + * The values in parenthesis are state labels. The rest are edge labels. + * + * (RUNNING) --FROZEN--> (FREEZING) --FROZEN--> (FROZEN) + * ^ ^ | | + * | \_______RUNNING_______/ | + * \_____________________________RUNNING___________/ + */ + +struct cgroup_subsys freezer_subsys; + +/* Locks taken and their ordering + * ------------------------------ + * css_set_lock + * cgroup_mutex (AKA cgroup_lock) + * task->alloc_lock (AKA task_lock) + * freezer->lock + * task->sighand->siglock + * + * cgroup code forces css_set_lock to be taken before task->alloc_lock + * + * freezer_create(), freezer_destroy(): + * cgroup_mutex [ by cgroup core ] + * + * can_attach(): + * cgroup_mutex + * + * cgroup_frozen(): + * task->alloc_lock (to get task's cgroup) + * + * freezer_fork() (preserving fork() performance means can't take cgroup_mutex): + * task->alloc_lock (to get task's cgroup) + * freezer->lock + * sighand->siglock (if the cgroup is freezing) + * + * freezer_read(): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * + * freezer_write() (freeze): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * sighand->siglock + * + * freezer_write() (unfreeze): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * task->alloc_lock (to prevent races with freeze_task()) + * sighand->siglock + */ +static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss, + struct cgroup *cgroup) +{ + struct freezer *freezer; + + freezer = kzalloc(sizeof(struct freezer), GFP_KERNEL); + if (!freezer) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&freezer->lock); + freezer->state = STATE_RUNNING; + return &freezer->css; +} + +static void freezer_destroy(struct cgroup_subsys *ss, + struct cgroup *cgroup) +{ + kfree(cgroup_freezer(cgroup)); +} + + +static int freezer_can_attach(struct cgroup_subsys *ss, + struct cgroup *new_cgroup, + struct task_struct *task) +{ + struct freezer *freezer; + int retval = 0; + + /* + * The call to cgroup_lock() in the freezer.state write method prevents + * a write to that file racing against an attach, and hence the + * can_attach() result will remain valid until the attach completes. + */ + freezer = cgroup_freezer(new_cgroup); + if (freezer->state == STATE_FROZEN) + retval = -EBUSY; + return retval; +} + +static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) +{ + struct freezer *freezer; + + task_lock(task); + freezer = task_freezer(task); + task_unlock(task); + + BUG_ON(freezer->state == STATE_FROZEN); + spin_lock_irq(&freezer->lock); + /* Locking avoids race with FREEZING -> RUNNING transitions. */ + if (freezer->state == STATE_FREEZING) + freeze_task(task, true); + spin_unlock_irq(&freezer->lock); +} + +/* + * caller must hold freezer->lock + */ +static void check_if_frozen(struct cgroup *cgroup, + struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + unsigned int nfrozen = 0, ntotal = 0; + + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + ntotal++; + /* + * Task is frozen or will freeze immediately when next it gets + * woken + */ + if (frozen(task) || + (task_is_stopped_or_traced(task) && freezing(task))) + nfrozen++; + } + + /* + * Transition to FROZEN when no new tasks can be added ensures + * that we never exist in the FROZEN state while there are unfrozen + * tasks. + */ + if (nfrozen == ntotal) + freezer->state = STATE_FROZEN; + cgroup_iter_end(cgroup, &it); +} + +static int freezer_read(struct cgroup *cgroup, struct cftype *cft, + struct seq_file *m) +{ + struct freezer *freezer; + enum freezer_state state; + + if (!cgroup_lock_live_group(cgroup)) + return -ENODEV; + + freezer = cgroup_freezer(cgroup); + spin_lock_irq(&freezer->lock); + state = freezer->state; + if (state == STATE_FREEZING) { + /* We change from FREEZING to FROZEN lazily if the cgroup was + * only partially frozen when we exitted write. */ + check_if_frozen(cgroup, freezer); + state = freezer->state; + } + spin_unlock_irq(&freezer->lock); + cgroup_unlock(); + + seq_puts(m, freezer_state_strs[state]); + seq_putc(m, '\n'); + return 0; +} + +static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + unsigned int num_cant_freeze_now = 0; + + freezer->state = STATE_FREEZING; + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + if (!freeze_task(task, true)) + continue; + if (task_is_stopped_or_traced(task) && freezing(task)) + /* + * The freeze flag is set so these tasks will + * immediately go into the fridge upon waking. + */ + continue; + if (!freezing(task) && !freezer_should_skip(task)) + num_cant_freeze_now++; + } + cgroup_iter_end(cgroup, &it); + + return num_cant_freeze_now ? -EBUSY : 0; +} + +static int unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + int do_wake; + + task_lock(task); + do_wake = __thaw_process(task); + task_unlock(task); + if (do_wake) + wake_up_process(task); + } + cgroup_iter_end(cgroup, &it); + freezer->state = STATE_RUNNING; + + return 0; +} + +static int freezer_change_state(struct cgroup *cgroup, + enum freezer_state goal_state) +{ + struct freezer *freezer; + int retval = 0; + + freezer = cgroup_freezer(cgroup); + spin_lock_irq(&freezer->lock); + check_if_frozen(cgroup, freezer); /* may update freezer->state */ + if (goal_state == freezer->state) + goto out; + switch (freezer->state) { + case STATE_RUNNING: + retval = try_to_freeze_cgroup(cgroup, freezer); + break; + case STATE_FREEZING: + if (goal_state == STATE_FROZEN) { + /* Userspace is retrying after + * "/bin/echo FROZEN > freezer.state" returned -EBUSY */ + retval = try_to_freeze_cgroup(cgroup, freezer); + break; + } + /* state == FREEZING and goal_state == RUNNING, so unfreeze */ + case STATE_FROZEN: + retval = unfreeze_cgroup(cgroup, freezer); + break; + default: + break; + } +out: + spin_unlock_irq(&freezer->lock); + + return retval; +} + +static int freezer_write(struct cgroup *cgroup, + struct cftype *cft, + const char *buffer) +{ + int retval; + enum freezer_state goal_state; + + if (strcmp(buffer, freezer_state_strs[STATE_RUNNING]) == 0) + goal_state = STATE_RUNNING; + else if (strcmp(buffer, freezer_state_strs[STATE_FROZEN]) == 0) + goal_state = STATE_FROZEN; + else + return -EIO; + + if (!cgroup_lock_live_group(cgroup)) + return -ENODEV; + retval = freezer_change_state(cgroup, goal_state); + cgroup_unlock(); + return retval; +} + +static struct cftype files[] = { + { + .name = "state", + .read_seq_string = freezer_read, + .write_string = freezer_write, + }, +}; + +static int freezer_populate(struct cgroup_subsys *ss, struct cgroup *cgroup) +{ + return cgroup_add_files(cgroup, ss, files, ARRAY_SIZE(files)); +} + +struct cgroup_subsys freezer_subsys = { + .name = "freezer", + .create = freezer_create, + .destroy = freezer_destroy, + .populate = freezer_populate, + .subsys_id = freezer_subsys_id, + .can_attach = freezer_can_attach, + .attach = NULL, + .fork = freezer_fork, + .exit = NULL, +}; diff --git a/kernel/freezer.c b/kernel/freezer.c index cb0931f..ba6248b 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -120,3 +120,35 @@ void cancel_freezing(struct task_struct *p) spin_unlock_irqrestore(&p->sighand->siglock, flags); } } + +/* + * Wake up a frozen process + * + * task_lock() is needed to prevent the race with refrigerator() which may + * occur if the freezing of tasks fails. Namely, without the lock, if the + * freezing of tasks failed, thaw_tasks() might have run before a task in + * refrigerator() could call frozen_process(), in which case the task would be + * frozen and no one would thaw it. + */ +int __thaw_process(struct task_struct *p) +{ + if (frozen(p)) { + p->flags &= ~PF_FROZEN; + return 1; + } + clear_freeze_flag(p); + return 0; +} + +int thaw_process(struct task_struct *p) +{ + task_lock(p); + if (__thaw_process(p) == 1) { + task_unlock(p); + wake_up_process(p); + return 1; + } + task_unlock(p); + return 0; +} +EXPORT_SYMBOL(thaw_process); diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index ebdd7f5..dcd165f 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -85,9 +85,6 @@ config PM_SLEEP depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y -config FREEZER - def_bool PM_SLEEP - config SUSPEND bool "Suspend to RAM and standby" depends on PM && ARCH_SUSPEND_POSSIBLE -- cgit v1.1 From 5a06915c6df9b89cda5ddb3f8cce5f9a6be534d2 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:22 -0700 Subject: container freezer: skip frozen cgroups during power management resume When a system is resumed after a suspend, it will also unfreeze frozen cgroups. This patchs modifies the resume sequence to skip the tasks which are part of a frozen control group. Signed-off-by: Cedric Le Goater Signed-off-by: Matt Helsley Acked-by: Serge E. Hallyn Tested-by: Matt Helsley Acked-by: Rafael J. Wysocki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/process.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/power/process.c b/kernel/power/process.c index 444cea8..ca63401 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -135,6 +135,9 @@ static void thaw_tasks(bool nosig_only) if (nosig_only && should_send_signal(p)) continue; + if (cgroup_frozen(p)) + continue; + thaw_process(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); -- cgit v1.1 From 957a4eeaf4af614ab0fc4c09a22593d6ab233f5b Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:22 -0700 Subject: container freezer: prevent frozen tasks or cgroups from changing Don't let frozen tasks or cgroups change. This means frozen tasks can't leave their current cgroup for another cgroup. It also means that tasks cannot be added to or removed from a cgroup in the FROZEN state. We enforce these rules by checking for frozen tasks and cgroups in the can_attach() function. Signed-off-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index b08722d..df88402 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -145,22 +145,40 @@ static void freezer_destroy(struct cgroup_subsys *ss, kfree(cgroup_freezer(cgroup)); } +/* Task is frozen or will freeze immediately when next it gets woken */ +static bool is_task_frozen_enough(struct task_struct *task) +{ + return frozen(task) || + (task_is_stopped_or_traced(task) && freezing(task)); +} +/* + * The call to cgroup_lock() in the freezer.state write method prevents + * a write to that file racing against an attach, and hence the + * can_attach() result will remain valid until the attach completes. + */ static int freezer_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, struct task_struct *task) { struct freezer *freezer; - int retval = 0; + int retval; + + /* Anything frozen can't move or be moved to/from */ + + if (is_task_frozen_enough(task)) + return -EBUSY; - /* - * The call to cgroup_lock() in the freezer.state write method prevents - * a write to that file racing against an attach, and hence the - * can_attach() result will remain valid until the attach completes. - */ freezer = cgroup_freezer(new_cgroup); if (freezer->state == STATE_FROZEN) + return -EBUSY; + + retval = 0; + task_lock(task); + freezer = task_freezer(task); + if (freezer->state == STATE_FROZEN) retval = -EBUSY; + task_unlock(task); return retval; } @@ -193,12 +211,7 @@ static void check_if_frozen(struct cgroup *cgroup, cgroup_iter_start(cgroup, &it); while ((task = cgroup_iter_next(cgroup, &it))) { ntotal++; - /* - * Task is frozen or will freeze immediately when next it gets - * woken - */ - if (frozen(task) || - (task_is_stopped_or_traced(task) && freezing(task))) + if (is_task_frozen_enough(task)) nfrozen++; } @@ -249,11 +262,7 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) while ((task = cgroup_iter_next(cgroup, &it))) { if (!freeze_task(task, true)) continue; - if (task_is_stopped_or_traced(task) && freezing(task)) - /* - * The freeze flag is set so these tasks will - * immediately go into the fridge upon waking. - */ + if (is_task_frozen_enough(task)) continue; if (!freezing(task) && !freezer_should_skip(task)) num_cant_freeze_now++; -- cgit v1.1 From 81dcf33c2ae314899f754aa7aaa1cb1fe2f84da6 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:23 -0700 Subject: container freezer: make freezer state names less generic Rename cgroup freezer states to be less generic to avoid any name collisions while also better describing what each state is. Signed-off-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 56 ++++++++++++++++++++++++------------------------- 1 file changed, 28 insertions(+), 28 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index df88402..6e4280d 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -22,9 +22,9 @@ #include enum freezer_state { - STATE_RUNNING = 0, - STATE_FREEZING, - STATE_FROZEN, + CGROUP_THAWED = 0, + CGROUP_FREEZING, + CGROUP_FROZEN, }; struct freezer { @@ -57,7 +57,7 @@ int cgroup_frozen(struct task_struct *task) state = freezer->state; task_unlock(task); - return state == STATE_FROZEN; + return state == CGROUP_FROZEN; } /* @@ -65,7 +65,7 @@ int cgroup_frozen(struct task_struct *task) * CGROUP_LOCAL_BUFFER_SIZE */ static const char *freezer_state_strs[] = { - "RUNNING", + "THAWED", "FREEZING", "FROZEN", }; @@ -75,10 +75,10 @@ static const char *freezer_state_strs[] = { * Transitions are caused by userspace writes to the freezer.state file. * The values in parenthesis are state labels. The rest are edge labels. * - * (RUNNING) --FROZEN--> (FREEZING) --FROZEN--> (FROZEN) - * ^ ^ | | - * | \_______RUNNING_______/ | - * \_____________________________RUNNING___________/ + * (THAWED) --FROZEN--> (FREEZING) --FROZEN--> (FROZEN) + * ^ ^ | | + * | \_______THAWED_______/ | + * \__________________________THAWED____________/ */ struct cgroup_subsys freezer_subsys; @@ -135,7 +135,7 @@ static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss, return ERR_PTR(-ENOMEM); spin_lock_init(&freezer->lock); - freezer->state = STATE_RUNNING; + freezer->state = CGROUP_THAWED; return &freezer->css; } @@ -170,13 +170,13 @@ static int freezer_can_attach(struct cgroup_subsys *ss, return -EBUSY; freezer = cgroup_freezer(new_cgroup); - if (freezer->state == STATE_FROZEN) + if (freezer->state == CGROUP_FROZEN) return -EBUSY; retval = 0; task_lock(task); freezer = task_freezer(task); - if (freezer->state == STATE_FROZEN) + if (freezer->state == CGROUP_FROZEN) retval = -EBUSY; task_unlock(task); return retval; @@ -190,10 +190,10 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) freezer = task_freezer(task); task_unlock(task); - BUG_ON(freezer->state == STATE_FROZEN); + BUG_ON(freezer->state == CGROUP_FROZEN); spin_lock_irq(&freezer->lock); - /* Locking avoids race with FREEZING -> RUNNING transitions. */ - if (freezer->state == STATE_FREEZING) + /* Locking avoids race with FREEZING -> THAWED transitions. */ + if (freezer->state == CGROUP_FREEZING) freeze_task(task, true); spin_unlock_irq(&freezer->lock); } @@ -221,7 +221,7 @@ static void check_if_frozen(struct cgroup *cgroup, * tasks. */ if (nfrozen == ntotal) - freezer->state = STATE_FROZEN; + freezer->state = CGROUP_FROZEN; cgroup_iter_end(cgroup, &it); } @@ -237,7 +237,7 @@ static int freezer_read(struct cgroup *cgroup, struct cftype *cft, freezer = cgroup_freezer(cgroup); spin_lock_irq(&freezer->lock); state = freezer->state; - if (state == STATE_FREEZING) { + if (state == CGROUP_FREEZING) { /* We change from FREEZING to FROZEN lazily if the cgroup was * only partially frozen when we exitted write. */ check_if_frozen(cgroup, freezer); @@ -257,7 +257,7 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) struct task_struct *task; unsigned int num_cant_freeze_now = 0; - freezer->state = STATE_FREEZING; + freezer->state = CGROUP_FREEZING; cgroup_iter_start(cgroup, &it); while ((task = cgroup_iter_next(cgroup, &it))) { if (!freeze_task(task, true)) @@ -288,7 +288,7 @@ static int unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) wake_up_process(task); } cgroup_iter_end(cgroup, &it); - freezer->state = STATE_RUNNING; + freezer->state = CGROUP_THAWED; return 0; } @@ -305,18 +305,18 @@ static int freezer_change_state(struct cgroup *cgroup, if (goal_state == freezer->state) goto out; switch (freezer->state) { - case STATE_RUNNING: + case CGROUP_THAWED: retval = try_to_freeze_cgroup(cgroup, freezer); break; - case STATE_FREEZING: - if (goal_state == STATE_FROZEN) { + case CGROUP_FREEZING: + if (goal_state == CGROUP_FROZEN) { /* Userspace is retrying after * "/bin/echo FROZEN > freezer.state" returned -EBUSY */ retval = try_to_freeze_cgroup(cgroup, freezer); break; } - /* state == FREEZING and goal_state == RUNNING, so unfreeze */ - case STATE_FROZEN: + /* state == FREEZING and goal_state == THAWED, so unfreeze */ + case CGROUP_FROZEN: retval = unfreeze_cgroup(cgroup, freezer); break; default: @@ -335,10 +335,10 @@ static int freezer_write(struct cgroup *cgroup, int retval; enum freezer_state goal_state; - if (strcmp(buffer, freezer_state_strs[STATE_RUNNING]) == 0) - goal_state = STATE_RUNNING; - else if (strcmp(buffer, freezer_state_strs[STATE_FROZEN]) == 0) - goal_state = STATE_FROZEN; + if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0) + goal_state = CGROUP_THAWED; + else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0) + goal_state = CGROUP_FROZEN; else return -EIO; -- cgit v1.1 From 1aece34833721d64eb33fc15cd923c727296d3d3 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:24 -0700 Subject: container freezer: rename check_if_frozen() check_if_frozen() sounds like it should return something when in fact it's just updating the freezer state. Signed-off-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 6e4280d..e950569 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -201,8 +201,8 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) /* * caller must hold freezer->lock */ -static void check_if_frozen(struct cgroup *cgroup, - struct freezer *freezer) +static void update_freezer_state(struct cgroup *cgroup, + struct freezer *freezer) { struct cgroup_iter it; struct task_struct *task; @@ -222,6 +222,10 @@ static void check_if_frozen(struct cgroup *cgroup, */ if (nfrozen == ntotal) freezer->state = CGROUP_FROZEN; + else if (nfrozen > 0) + freezer->state = CGROUP_FREEZING; + else + freezer->state = CGROUP_THAWED; cgroup_iter_end(cgroup, &it); } @@ -240,7 +244,7 @@ static int freezer_read(struct cgroup *cgroup, struct cftype *cft, if (state == CGROUP_FREEZING) { /* We change from FREEZING to FROZEN lazily if the cgroup was * only partially frozen when we exitted write. */ - check_if_frozen(cgroup, freezer); + update_freezer_state(cgroup, freezer); state = freezer->state; } spin_unlock_irq(&freezer->lock); @@ -301,7 +305,7 @@ static int freezer_change_state(struct cgroup *cgroup, freezer = cgroup_freezer(cgroup); spin_lock_irq(&freezer->lock); - check_if_frozen(cgroup, freezer); /* may update freezer->state */ + update_freezer_state(cgroup, freezer); if (goal_state == freezer->state) goto out; switch (freezer->state) { -- cgit v1.1 From c3b9f5afc7f4c8abc0452f132edb13ac8c1fafbf Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Sat, 18 Oct 2008 20:27:29 -0700 Subject: kernel/configs.c: remove useless comments These comments are useless, remove them. Signed-off-by: WANG Cong Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/configs.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'kernel') diff --git a/kernel/configs.c b/kernel/configs.c index 4c34521..abaee68 100644 --- a/kernel/configs.c +++ b/kernel/configs.c @@ -54,9 +54,6 @@ #ifdef CONFIG_IKCONFIG_PROC -/**************************************************/ -/* globals and useful constants */ - static ssize_t ikconfig_read_current(struct file *file, char __user *buf, size_t len, loff_t * offset) @@ -71,9 +68,6 @@ static const struct file_operations ikconfig_file_ops = { .read = ikconfig_read_current, }; -/***************************************************/ -/* ikconfig_init: start up everything we need to */ - static int __init ikconfig_init(void) { struct proc_dir_entry *entry; @@ -89,9 +83,6 @@ static int __init ikconfig_init(void) return 0; } -/***************************************************/ -/* ikconfig_cleanup: clean up our mess */ - static void __exit ikconfig_cleanup(void) { remove_proc_entry("config.gz", NULL); -- cgit v1.1 From 146aa1bd0511f88ddb4e92fafa2b8aad4f2f65f3 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Sat, 18 Oct 2008 20:28:03 -0700 Subject: cgroups: fix probable race with put_css_set[_taskexit] and find_css_set put_css_set_taskexit may be called when find_css_set is called on other cpu. And the race will occur: put_css_set_taskexit side find_css_set side | atomic_dec_and_test(&kref->refcount) | /* kref->refcount = 0 */ | .................................................................... | read_lock(&css_set_lock) | find_existing_css_set | get_css_set | read_unlock(&css_set_lock); .................................................................... __release_css_set | .................................................................... | /* use a released css_set */ | [put_css_set is the same. But in the current code, all put_css_set are put into cgroup mutex critical region as the same as find_css_set.] [akpm@linux-foundation.org: repair comments] [menage@google.com: eliminate race in css_set refcounting] Signed-off-by: Lai Jiangshan Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Signed-off-by: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 43 ++++++++++++++++++++----------------------- kernel/cgroup_debug.c | 4 ++-- 2 files changed, 22 insertions(+), 25 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8c6e1c1..1e49218 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -241,7 +241,6 @@ static void unlink_css_set(struct css_set *cg) struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; - write_lock(&css_set_lock); hlist_del(&cg->hlist); css_set_count--; @@ -251,16 +250,25 @@ static void unlink_css_set(struct css_set *cg) list_del(&link->cgrp_link_list); kfree(link); } - - write_unlock(&css_set_lock); } -static void __release_css_set(struct kref *k, int taskexit) +static void __put_css_set(struct css_set *cg, int taskexit) { int i; - struct css_set *cg = container_of(k, struct css_set, ref); - + /* + * Ensure that the refcount doesn't hit zero while any readers + * can see it. Similar to atomic_dec_and_lock(), but for an + * rwlock + */ + if (atomic_add_unless(&cg->refcount, -1, 1)) + return; + write_lock(&css_set_lock); + if (!atomic_dec_and_test(&cg->refcount)) { + write_unlock(&css_set_lock); + return; + } unlink_css_set(cg); + write_unlock(&css_set_lock); rcu_read_lock(); for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { @@ -276,32 +284,22 @@ static void __release_css_set(struct kref *k, int taskexit) kfree(cg); } -static void release_css_set(struct kref *k) -{ - __release_css_set(k, 0); -} - -static void release_css_set_taskexit(struct kref *k) -{ - __release_css_set(k, 1); -} - /* * refcounted get/put for css_set objects */ static inline void get_css_set(struct css_set *cg) { - kref_get(&cg->ref); + atomic_inc(&cg->refcount); } static inline void put_css_set(struct css_set *cg) { - kref_put(&cg->ref, release_css_set); + __put_css_set(cg, 0); } static inline void put_css_set_taskexit(struct css_set *cg) { - kref_put(&cg->ref, release_css_set_taskexit); + __put_css_set(cg, 1); } /* @@ -427,7 +425,7 @@ static struct css_set *find_css_set( return NULL; } - kref_init(&res->ref); + atomic_set(&res->refcount, 1); INIT_LIST_HEAD(&res->cg_links); INIT_LIST_HEAD(&res->tasks); INIT_HLIST_NODE(&res->hlist); @@ -1728,7 +1726,7 @@ int cgroup_task_count(const struct cgroup *cgrp) read_lock(&css_set_lock); list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) { - count += atomic_read(&link->cg->ref.refcount); + count += atomic_read(&link->cg->refcount); } read_unlock(&css_set_lock); return count; @@ -2495,8 +2493,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) int __init cgroup_init_early(void) { int i; - kref_init(&init_css_set.ref); - kref_get(&init_css_set.ref); + atomic_set(&init_css_set.refcount, 1); INIT_LIST_HEAD(&init_css_set.cg_links); INIT_LIST_HEAD(&init_css_set.tasks); INIT_HLIST_NODE(&init_css_set.hlist); diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c index c3dc3ab..daca620 100644 --- a/kernel/cgroup_debug.c +++ b/kernel/cgroup_debug.c @@ -57,7 +57,7 @@ static u64 current_css_set_refcount_read(struct cgroup *cont, u64 count; rcu_read_lock(); - count = atomic_read(¤t->cgroups->ref.refcount); + count = atomic_read(¤t->cgroups->refcount); rcu_read_unlock(); return count; } @@ -90,7 +90,7 @@ static struct cftype files[] = { { .name = "releasable", .read_u64 = releasable_read, - } + }, }; static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) -- cgit v1.1 From cc31edceee04a7b87f2be48f9489ebb72d264844 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Sat, 18 Oct 2008 20:28:04 -0700 Subject: cgroups: convert tasks file to use a seq_file with shared pid array Rather than pre-generating the entire text for the "tasks" file each time the file is opened, we instead just generate/update the array of process ids and use a seq_file to report these to userspace. All open file handles on the same "tasks" file can share a pid array, which may be updated any time that no thread is actively reading the array. By sharing the array, the potential for userspace to DoS the system by opening many handles on the same "tasks" file is removed. [Based on a patch by Lai Jiangshan, extended to use seq_file] Signed-off-by: Paul Menage Reviewed-by: Lai Jiangshan Cc: Serge Hallyn Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 222 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 139 insertions(+), 83 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 1e49218..046c160 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -868,6 +868,14 @@ static struct super_operations cgroup_ops = { .remount_fs = cgroup_remount, }; +static void init_cgroup_housekeeping(struct cgroup *cgrp) +{ + INIT_LIST_HEAD(&cgrp->sibling); + INIT_LIST_HEAD(&cgrp->children); + INIT_LIST_HEAD(&cgrp->css_sets); + INIT_LIST_HEAD(&cgrp->release_list); + init_rwsem(&cgrp->pids_mutex); +} static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; @@ -876,10 +884,7 @@ static void init_cgroup_root(struct cgroupfs_root *root) root->number_of_cgroups = 1; cgrp->root = root; cgrp->top_cgroup = cgrp; - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); } static int cgroup_test_super(struct super_block *sb, void *data) @@ -1995,16 +2000,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * but we cannot guarantee that the information we produce is correct * unless we produce it entirely atomically. * - * Upon tasks file open(), a struct ctr_struct is allocated, that - * will have a pointer to an array (also allocated here). The struct - * ctr_struct * is stored in file->private_data. Its resources will - * be freed by release() when the file is closed. The array is used - * to sprintf the PIDs and then used by read(). */ -struct ctr_struct { - char *buf; - int bufsz; -}; /* * Load into 'pidarray' up to 'npids' of the tasks using cgroup @@ -2086,42 +2082,132 @@ static int cmppid(const void *a, const void *b) return *(pid_t *)a - *(pid_t *)b; } + /* - * Convert array 'a' of 'npids' pid_t's to a string of newline separated - * decimal pids in 'buf'. Don't write more than 'sz' chars, but return - * count 'cnt' of how many chars would be written if buf were large enough. + * seq_file methods for the "tasks" file. The seq_file position is the + * next pid to display; the seq_file iterator is a pointer to the pid + * in the cgroup->tasks_pids array. */ -static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids) + +static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) { - int cnt = 0; - int i; + /* + * Initially we receive a position value that corresponds to + * one more than the last pid shown (or 0 on the first call or + * after a seek to the start). Use a binary-search to find the + * next pid to display, if any + */ + struct cgroup *cgrp = s->private; + int index = 0, pid = *pos; + int *iter; - for (i = 0; i < npids; i++) - cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]); - return cnt; + down_read(&cgrp->pids_mutex); + if (pid) { + int end = cgrp->pids_length; + int i; + while (index < end) { + int mid = (index + end) / 2; + if (cgrp->tasks_pids[mid] == pid) { + index = mid; + break; + } else if (cgrp->tasks_pids[mid] <= pid) + index = mid + 1; + else + end = mid; + } + } + /* If we're off the end of the array, we're done */ + if (index >= cgrp->pids_length) + return NULL; + /* Update the abstract position to be the actual pid that we found */ + iter = cgrp->tasks_pids + index; + *pos = *iter; + return iter; +} + +static void cgroup_tasks_stop(struct seq_file *s, void *v) +{ + struct cgroup *cgrp = s->private; + up_read(&cgrp->pids_mutex); } +static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct cgroup *cgrp = s->private; + int *p = v; + int *end = cgrp->tasks_pids + cgrp->pids_length; + + /* + * Advance to the next pid in the array. If this goes off the + * end, we're done + */ + p++; + if (p >= end) { + return NULL; + } else { + *pos = *p; + return p; + } +} + +static int cgroup_tasks_show(struct seq_file *s, void *v) +{ + return seq_printf(s, "%d\n", *(int *)v); +} + +static struct seq_operations cgroup_tasks_seq_operations = { + .start = cgroup_tasks_start, + .stop = cgroup_tasks_stop, + .next = cgroup_tasks_next, + .show = cgroup_tasks_show, +}; + +static void release_cgroup_pid_array(struct cgroup *cgrp) +{ + down_write(&cgrp->pids_mutex); + BUG_ON(!cgrp->pids_use_count); + if (!--cgrp->pids_use_count) { + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = NULL; + cgrp->pids_length = 0; + } + up_write(&cgrp->pids_mutex); +} + +static int cgroup_tasks_release(struct inode *inode, struct file *file) +{ + struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); + + if (!(file->f_mode & FMODE_READ)) + return 0; + + release_cgroup_pid_array(cgrp); + return seq_release(inode, file); +} + +static struct file_operations cgroup_tasks_operations = { + .read = seq_read, + .llseek = seq_lseek, + .write = cgroup_file_write, + .release = cgroup_tasks_release, +}; + /* - * Handle an open on 'tasks' file. Prepare a buffer listing the + * Handle an open on 'tasks' file. Prepare an array containing the * process id's of tasks currently attached to the cgroup being opened. - * - * Does not require any specific cgroup mutexes, and does not take any. */ + static int cgroup_tasks_open(struct inode *unused, struct file *file) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - struct ctr_struct *ctr; pid_t *pidarray; int npids; - char c; + int retval; + /* Nothing to do for write-only files */ if (!(file->f_mode & FMODE_READ)) return 0; - ctr = kmalloc(sizeof(*ctr), GFP_KERNEL); - if (!ctr) - goto err0; - /* * If cgroup gets more users after we read count, we won't have * enough space - tough. This race is indistinguishable to the @@ -2129,57 +2215,31 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file) * show up until sometime later on. */ npids = cgroup_task_count(cgrp); - if (npids) { - pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); - if (!pidarray) - goto err1; - - npids = pid_array_load(pidarray, npids, cgrp); - sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - - /* Call pid_array_to_buf() twice, first just to get bufsz */ - ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1; - ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL); - if (!ctr->buf) - goto err2; - ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids); - - kfree(pidarray); - } else { - ctr->buf = NULL; - ctr->bufsz = 0; - } - file->private_data = ctr; - return 0; - -err2: - kfree(pidarray); -err1: - kfree(ctr); -err0: - return -ENOMEM; -} - -static ssize_t cgroup_tasks_read(struct cgroup *cgrp, - struct cftype *cft, - struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) -{ - struct ctr_struct *ctr = file->private_data; + pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); + if (!pidarray) + return -ENOMEM; + npids = pid_array_load(pidarray, npids, cgrp); + sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - return simple_read_from_buffer(buf, nbytes, ppos, ctr->buf, ctr->bufsz); -} + /* + * Store the array in the cgroup, freeing the old + * array if necessary + */ + down_write(&cgrp->pids_mutex); + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = pidarray; + cgrp->pids_length = npids; + cgrp->pids_use_count++; + up_write(&cgrp->pids_mutex); -static int cgroup_tasks_release(struct inode *unused_inode, - struct file *file) -{ - struct ctr_struct *ctr; + file->f_op = &cgroup_tasks_operations; - if (file->f_mode & FMODE_READ) { - ctr = file->private_data; - kfree(ctr->buf); - kfree(ctr); + retval = seq_open(file, &cgroup_tasks_seq_operations); + if (retval) { + release_cgroup_pid_array(cgrp); + return retval; } + ((struct seq_file *)file->private_data)->private = cgrp; return 0; } @@ -2208,7 +2268,6 @@ static struct cftype files[] = { { .name = "tasks", .open = cgroup_tasks_open, - .read = cgroup_tasks_read, .write_u64 = cgroup_tasks_write, .release = cgroup_tasks_release, .private = FILE_TASKLIST, @@ -2298,10 +2357,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, mutex_lock(&cgroup_mutex); - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); cgrp->parent = parent; cgrp->root = parent->root; -- cgit v1.1 From 40b6a76237563c70466ec7315f644ba87d57dbe5 Mon Sep 17 00:00:00 2001 From: Rakib Mullick Date: Sat, 18 Oct 2008 20:28:18 -0700 Subject: cpuset.c: remove extra variable Remove the use of int cpus_nonempty variable from 'update_flag' function. Signed-off-by: Md.Rakib H. Mullick Acked-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index eab7bd6..81d4d24 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1172,7 +1172,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, { struct cpuset trialcs; int err; - int cpus_nonempty, balance_flag_changed; + int balance_flag_changed; trialcs = *cs; if (turning_on) @@ -1184,7 +1184,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, if (err < 0) return err; - cpus_nonempty = !cpus_empty(trialcs.cpus_allowed); balance_flag_changed = (is_sched_load_balance(cs) != is_sched_load_balance(&trialcs)); @@ -1192,7 +1191,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, cs->flags = trialcs.flags; mutex_unlock(&callback_mutex); - if (cpus_nonempty && balance_flag_changed) + if (!cpus_empty(trialcs.cpus_allowed) && balance_flag_changed) async_rebuild_sched_domains(); return 0; -- cgit v1.1 From 30e8e13603c247c301fdacabef2a765c84840994 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Sat, 18 Oct 2008 20:28:20 -0700 Subject: cpuset: use seq_*mask_* to print masks 1) seq_file excepts that m->count == m->size when it's buf is full, so current code will causes bugs when buf is overflow. 2) There is not too good that cpuset accesses struct seq_file's fields directly. Signed-off-by: Lai Jiangshan Cc: Alexey Dobriyan Acked-by: Paul Menage Cc: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 81d4d24..3e00526 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2436,19 +2436,15 @@ const struct file_operations proc_cpuset_operations = { void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) { seq_printf(m, "Cpus_allowed:\t"); - m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count, - task->cpus_allowed); + seq_cpumask(m, &task->cpus_allowed); seq_printf(m, "\n"); seq_printf(m, "Cpus_allowed_list:\t"); - m->count += cpulist_scnprintf(m->buf + m->count, m->size - m->count, - task->cpus_allowed); + seq_cpumask_list(m, &task->cpus_allowed); seq_printf(m, "\n"); seq_printf(m, "Mems_allowed:\t"); - m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count, - task->mems_allowed); + seq_nodemask(m, &task->mems_allowed); seq_printf(m, "\n"); seq_printf(m, "Mems_allowed_list:\t"); - m->count += nodelist_scnprintf(m->buf + m->count, m->size - m->count, - task->mems_allowed); + seq_nodemask_list(m, &task->mems_allowed); seq_printf(m, "\n"); } -- cgit v1.1 From b747c8c102cc0677a7a8056a093f58d7c9b500e7 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Sat, 18 Oct 2008 20:28:21 -0700 Subject: make ptrace_untrace() static ptrace_untrace() can now become static. Signed-off-by: Adrian Bunk Cc: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 356699a..1e68e4c 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -45,7 +45,7 @@ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) * TASK_TRACED, resume it now. * Requires that irqs be disabled. */ -void ptrace_untrace(struct task_struct *child) +static void ptrace_untrace(struct task_struct *child) { spin_lock(&child->sighand->siglock); if (task_is_traced(child)) { -- cgit v1.1 From 293adee601bcd4cdb5076a9bda187137de17e96e Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sat, 18 Oct 2008 20:28:24 -0700 Subject: kthread_bind: use wait_task_inactive(TASK_UNINTERRUPTIBLE) Now that wait_task_inactive(task, state) checks task->state == state, we can simplify the code and make this debugging check more robust. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kthread.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/kthread.c b/kernel/kthread.c index 96cff2f..14ec64f 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -171,12 +171,11 @@ EXPORT_SYMBOL(kthread_create); */ void kthread_bind(struct task_struct *k, unsigned int cpu) { - if (k->state != TASK_UNINTERRUPTIBLE) { + /* Must have done schedule() in kthread() before we set_task_cpu */ + if (!wait_task_inactive(k, TASK_UNINTERRUPTIBLE)) { WARN_ON(1); return; } - /* Must have done schedule() in kthread() before we set_task_cpu */ - wait_task_inactive(k, 0); set_task_cpu(k, cpu); k->cpus_allowed = cpumask_of_cpu(cpu); k->rt.nr_cpus_allowed = 1; -- cgit v1.1 From acd99dbf54020f5c80b9aa2f2ea86f43cb285b02 Mon Sep 17 00:00:00 2001 From: Ken'ichi Ohmichi Date: Sat, 18 Oct 2008 20:28:30 -0700 Subject: kdump: add vmlist.addr to vmcoreinfo for x86 vmalloc translation. Add the symbols 'vmlist' and offset 'vm_struct.addr' to the vmcoreinfo[1] data for i386 vmalloc translation. makedumpfile[2] needs VMALLOC_START value for distinguishing a vmalloc address or not, because it should choose suitable translation method. If applying this patch, makedumpfile will be able to take VMALLOC_START value from 'vmlist.addr'. vmcoreinfo[1]: The vmcoreinfo data has the minimum debugging information only for dump filtering. makedumpfile[2] uses it to distinguish unnecessary pages and creates a small dumpfile. makedumpfile[2]: dump filtering command https://sourceforge.net/projects/makedumpfile/ Signed-off-by: Ken'ichi Ohmichi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/kexec.c b/kernel/kexec.c index aef2653..777ac45 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1371,6 +1371,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(node_online_map); VMCOREINFO_SYMBOL(swapper_pg_dir); VMCOREINFO_SYMBOL(_stext); + VMCOREINFO_SYMBOL(vmlist); #ifndef CONFIG_NEED_MULTIPLE_NODES VMCOREINFO_SYMBOL(mem_map); @@ -1406,6 +1407,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_OFFSET(free_area, free_list); VMCOREINFO_OFFSET(list_head, next); VMCOREINFO_OFFSET(list_head, prev); + VMCOREINFO_OFFSET(vm_struct, addr); VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); VMCOREINFO_NUMBER(NR_FREE_PAGES); -- cgit v1.1 From 1a651a00e20fd4997f0b91258f6f95b7d96edcd9 Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Sat, 18 Oct 2008 20:28:37 -0700 Subject: byteorder: remove direct includes of linux/byteorder/swab[b].h A consolidated implementation will provide this generically through asm/byteorder, remove direct includes to avoid breakage when the changeover to the new implementation occurs. Signed-off-by: Harvey Harrison Acked-by: Mauro Carvalho Chehab Acked-by: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/rcupreempt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index ca4bbbe..59236e8 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -54,9 +54,9 @@ #include #include #include -#include #include #include +#include /* * PREEMPT_RCU data structures. -- cgit v1.1 From bd95b88d9e51fcbf392a7e90338a8fcc3499cbd6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 16 Oct 2008 09:31:27 -0400 Subject: ftrace: release functions from hash The x86 architecture uses a static recording of mcount caller locations and is not affected by this patch. For architectures still using the dynamic ftrace daemon, this patch is critical. It removes the race between the recording of a function that calls mcount, the unloading of a module, and the ftrace daemon updating the call sites. This patch adds the releasing of the hash functions that the daemon uses to update the mcount call sites. When a module is unloaded, not only are the replaced call site table update, but now so is the hash recorded functions that the ftrace daemon will use. Again, architectures that implement MCOUNT_RECORD are not affected by this (which currently only x86 has). Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4dda4f6..1f54a94 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -164,10 +164,14 @@ static DEFINE_SPINLOCK(ftrace_hash_lock); #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) #define ftrace_hash_unlock(flags) \ spin_unlock_irqrestore(&ftrace_hash_lock, flags) +static void ftrace_release_hash(unsigned long start, unsigned long end); #else /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) #define ftrace_hash_unlock(flags) do { } while(0) +static inline void ftrace_release_hash(unsigned long start, unsigned long end) +{ +} #endif /* @@ -347,6 +351,7 @@ void ftrace_release(void *start, unsigned long size) } spin_unlock(&ftrace_lock); + ftrace_release_hash(s, e); } static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) @@ -1659,6 +1664,44 @@ void __init ftrace_init(void) ftrace_disabled = 1; } #else /* CONFIG_FTRACE_MCOUNT_RECORD */ + +static void ftrace_release_hash(unsigned long start, unsigned long end) +{ + struct dyn_ftrace *rec; + struct hlist_node *t, *n; + struct hlist_head *head, temp_list; + unsigned long flags; + int i, cpu; + + preempt_disable_notrace(); + + /* disable incase we call something that calls mcount */ + cpu = raw_smp_processor_id(); + per_cpu(ftrace_shutdown_disable_cpu, cpu)++; + + ftrace_hash_lock(flags); + + for (i = 0; i < FTRACE_HASHSIZE; i++) { + INIT_HLIST_HEAD(&temp_list); + head = &ftrace_hash[i]; + + /* all CPUS are stopped, we are safe to modify code */ + hlist_for_each_entry_safe(rec, t, n, head, node) { + if (rec->flags & FTRACE_FL_FREE) + continue; + + if ((rec->ip >= start) && (rec->ip < end)) + ftrace_free_rec(rec); + } + } + + ftrace_hash_unlock(flags); + + per_cpu(ftrace_shutdown_disable_cpu, cpu)--; + preempt_enable_notrace(); + +} + static int ftraced(void *ignore) { unsigned long usecs; -- cgit v1.1 From c2db8054c1eaf99983d8deee347876b01c26c2cf Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:11 -0400 Subject: ftrace: fix depends A lot of tracers have HAVE_FTRACE as a dependent config where it really should not. The HAVE_FTRACE is a misnomer (soon to be fixed) and describes if the architecture has the function tracer (mcount) implemented. The ftrace infrastructure is implemented in all archs. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 5 ----- 1 file changed, 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1cb3e1f..5866edb 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -49,7 +49,6 @@ config IRQSOFF_TRACER default n depends on TRACE_IRQFLAGS_SUPPORT depends on GENERIC_TIME - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACE_IRQFLAGS select TRACING @@ -73,7 +72,6 @@ config PREEMPT_TRACER default n depends on GENERIC_TIME depends on PREEMPT - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select TRACER_MAX_TRACE @@ -101,7 +99,6 @@ config SYSPROF_TRACER config SCHED_TRACER bool "Scheduling Latency Tracer" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select CONTEXT_SWITCH_TRACER @@ -112,7 +109,6 @@ config SCHED_TRACER config CONTEXT_SWITCH_TRACER bool "Trace process context switches" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select MARKERS @@ -122,7 +118,6 @@ config CONTEXT_SWITCH_TRACER config BOOT_TRACER bool "Trace boot initcalls" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING help -- cgit v1.1 From 606576ce816603d9fe1fb453a88bc6eea16ca709 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:12 -0400 Subject: ftrace: rename FTRACE to FUNCTION_TRACER Due to confusion between the ftrace infrastructure and the gcc profiling tracer "ftrace", this patch renames the config options from FTRACE to FUNCTION_TRACER. The other two names that are offspring from FTRACE DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same. This patch was generated mostly by script, and partially by hand. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/Makefile | 4 ++-- kernel/sysctl.c | 2 +- kernel/trace/Kconfig | 17 +++++++++-------- kernel/trace/Makefile | 6 +++--- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 2 +- kernel/trace/trace_irqsoff.c | 4 ++-- kernel/trace/trace_sched_wakeup.c | 4 ++-- kernel/trace/trace_selftest.c | 4 ++-- 9 files changed, 23 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 8f9ce7e..85f588a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -13,7 +13,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ CFLAGS_REMOVE_sched.o = -mno-spe -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not trace debug files and internal ftrace files CFLAGS_REMOVE_lockdep.o = -pg CFLAGS_REMOVE_lockdep_proc.o = -pg @@ -86,7 +86,7 @@ obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o -obj-$(CONFIG_FTRACE) += trace/ +obj-$(CONFIG_FUNCTION_TRACER) += trace/ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 617d41e..619eb9f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -464,7 +464,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER { .ctl_name = CTL_UNNUMBERED, .procname = "ftrace_enabled", diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5866edb..3533c58 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -1,11 +1,12 @@ # -# Architectures that offer an FTRACE implementation should select HAVE_FTRACE: +# Architectures that offer an FUNCTION_TRACER implementation should +# select HAVE_FUNCTION_TRACER: # config NOP_TRACER bool -config HAVE_FTRACE +config HAVE_FUNCTION_TRACER bool select NOP_TRACER @@ -28,9 +29,9 @@ config TRACING select STACKTRACE select TRACEPOINTS -config FTRACE +config FUNCTION_TRACER bool "Kernel Function Tracer" - depends on HAVE_FTRACE + depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL select FRAME_POINTER select TRACING @@ -136,9 +137,9 @@ config BOOT_TRACER config STACK_TRACER bool "Trace max stack" - depends on HAVE_FTRACE + depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL - select FTRACE + select FUNCTION_TRACER select STACKTRACE help This special tracer records the maximum stack footprint of the @@ -155,7 +156,7 @@ config STACK_TRACER config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" - depends on FTRACE + depends on FUNCTION_TRACER depends on HAVE_DYNAMIC_FTRACE depends on DEBUG_KERNEL default y @@ -165,7 +166,7 @@ config DYNAMIC_FTRACE with a No-Op instruction) as they are called. A table is created to dynamically enable them again. - This way a CONFIG_FTRACE kernel is slightly larger, but otherwise + This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise has native performance as long as no tracing is active. The changes to the code are done by a kernel thread that diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index a85dfba..c8228b1 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -1,7 +1,7 @@ # Do not instrument the tracer itself: -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) @@ -10,13 +10,13 @@ CFLAGS_trace_selftest_dynamic.o = -pg obj-y += trace_selftest_dynamic.o endif -obj-$(CONFIG_FTRACE) += libftrace.o +obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o obj-$(CONFIG_RING_BUFFER) += ring_buffer.o obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o -obj-$(CONFIG_FTRACE) += trace_functions.o +obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d345d64..aeb2f25 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -851,7 +851,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) preempt_enable_notrace(); } -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER static void function_trace_call(unsigned long ip, unsigned long parent_ip) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f1f9957..6889ca4 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -335,7 +335,7 @@ void update_max_tr_single(struct trace_array *tr, extern cycle_t ftrace_now(int cpu); -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER void tracing_start_function_trace(void); void tracing_stop_function_trace(void); #else diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index a7db7f0..9c74071 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -63,7 +63,7 @@ irq_trace(void) */ static __cacheline_aligned_in_smp unsigned long max_sequence; -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* * irqsoff uses its own tracer function to keep the overhead down: */ @@ -104,7 +104,7 @@ static struct ftrace_ops trace_ops __read_mostly = { .func = irqsoff_tracer_call, }; -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ /* * Should this new latency be reported/recorded? diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index fe4a252..3ae93f1 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -31,7 +31,7 @@ static raw_spinlock_t wakeup_lock = static void __wakeup_reset(struct trace_array *tr); -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* * irqsoff uses its own tracer function to keep the overhead down: */ @@ -96,7 +96,7 @@ static struct ftrace_ops trace_ops __read_mostly = { .func = wakeup_tracer_call, }; -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ /* * Should this new latency be reported/recorded? diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 09cf230..95815d2 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -70,7 +70,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) return ret; } -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE @@ -226,7 +226,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) return ret; } -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_IRQSOFF_TRACER int -- cgit v1.1 From 3ce83aea86bf46fd1bff59d2e6d16f48fdce22fc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:13 -0400 Subject: ftrace: rename the ftrace tracer to function To avoid further confusion between the ftrace infrastructure and the function tracer. This patch renames the "ftrace" function tracer to "function". Now in available_tracers, instead of "ftrace" there will be "function". This makes more sense, since people will not know exactly what the "ftrace" tracer does. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_functions.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index e90eb0c..0f85a64 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -64,7 +64,7 @@ static void function_trace_ctrl_update(struct trace_array *tr) static struct tracer function_trace __read_mostly = { - .name = "ftrace", + .name = "function", .init = function_trace_init, .reset = function_trace_reset, .ctrl_update = function_trace_ctrl_update, -- cgit v1.1 From 81520a1b0649d0701205b818714a8c1e1cfbbb5b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 21:24:18 -0400 Subject: ftrace: stack tracer only record when on stack The stack trace API does not record if the stack is not on the current task's stack. That is, if the stack is the interrupt stack or NMI stack, the output does not show. Also, the size of those stacks are not consistent with the size of the thread stack, this makes the calculation of the stack size usually bogus. This all confuses the stack tracer. I unfortunately do not have time to fix all these problems, but this patch does record the worst stack when the stack pointer is on the tasks stack (instead of bogus numbers). The patch simply returns if the stack pointer is not on the task's stack. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 74c5d9a..be682b6 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -44,6 +44,10 @@ static inline void check_stack(void) if (this_size <= max_stack_size) return; + /* we do not handle interrupt stacks yet */ + if (!object_is_on_stack(&this_size)) + return; + raw_local_irq_save(flags); __raw_spin_lock(&max_stack_lock); -- cgit v1.1 From f07767fd0f95c385108fa4c456a9cb216a424fec Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Mon, 20 Oct 2008 10:23:38 -0700 Subject: byteorder: remove direct includes of linux/byteorder/swab[b].h A consolidated implementation will provide this generically through asm/byteorder, remove direct includes to avoid breakage when the changeover to the new implementation occurs. This hunk was lost from commit 1d8cca44b6a244b7e378546d719041819049a0f9 ("byteorder: provide swabb.h generically in asm/byteorder.h") Signed-off-by: Harvey Harrison Signed-off-by: Linus Torvalds --- kernel/rcutorture.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 90b5b12..85cb905 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -42,10 +42,10 @@ #include #include #include -#include #include #include #include +#include MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney and " -- cgit v1.1 From 5f41b8cdc6ef33b3432cee36264d628a80398362 Mon Sep 17 00:00:00 2001 From: "Luck, Tony" Date: Mon, 20 Oct 2008 15:23:40 -0700 Subject: kexec: fix crash_save_vmcoreinfo_init build problem This fixes kernel/kexec.c: In function 'crash_save_vmcoreinfo_init': kernel/kexec.c:1374: error: 'vmlist' undeclared (first use in this function) kernel/kexec.c:1374: error: (Each undeclared identifier is reported only once kernel/kexec.c:1374: error: for each function it appears in.) kernel/kexec.c:1410: error: invalid use of undefined type 'struct vm_struct' make[1]: *** [kernel/kexec.o] Error 1 Signed-off-by: Tony Luck Signed-off-by: Linus Torvalds --- kernel/kexec.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/kexec.c b/kernel/kexec.c index 777ac45..ac0fde7 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include -- cgit v1.1 From 0b3682ba33c59a362901b478bdab965da888b350 Mon Sep 17 00:00:00 2001 From: Chris Friesen Date: Mon, 20 Oct 2008 12:41:58 -0600 Subject: genirq: fix set_irq_type() when recording trigger type Impact: fix boot hang on a G5 In set_irq_type() we want to pass the type rather than the current interrupt state. Signed-off-by: Chris Friesen Acked-by: Benjamin Herrenschmidt Acked-by: David Brownell Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 4895fde..3de6ea3 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -127,7 +127,7 @@ int set_irq_type(unsigned int irq, unsigned int type) return 0; spin_lock_irqsave(&desc->lock, flags); - ret = __irq_set_trigger(desc, irq, flags); + ret = __irq_set_trigger(desc, irq, type); spin_unlock_irqrestore(&desc->lock, flags); return ret; } -- cgit v1.1 From 9a1c3542768b5a58e45a9216921cd10a3bae1205 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Feb 2008 20:40:24 -0500 Subject: [PATCH] pass fmode_t to blkdev_put() Signed-off-by: Al Viro --- kernel/power/swap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 80ccac8..7b9d611 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -178,7 +178,7 @@ static int swsusp_swap_check(void) /* This is called before saving image */ res = set_blocksize(resume_bdev, PAGE_SIZE); if (res < 0) - blkdev_put(resume_bdev); + blkdev_put(resume_bdev, FMODE_WRITE); return res; } @@ -574,7 +574,7 @@ int swsusp_read(unsigned int *flags_p) error = load_image(&handle, &snapshot, header->pages - 1); release_swap_reader(&handle); - blkdev_put(resume_bdev); + blkdev_put(resume_bdev, FMODE_READ); if (!error) pr_debug("PM: Image successfully loaded\n"); @@ -609,7 +609,7 @@ int swsusp_check(void) return -EINVAL; } if (error) - blkdev_put(resume_bdev); + blkdev_put(resume_bdev, FMODE_READ); else pr_debug("PM: Signature found, resuming\n"); } else { @@ -633,7 +633,7 @@ void swsusp_close(void) return; } - blkdev_put(resume_bdev); + blkdev_put(resume_bdev, 0); /* move up */ } static int swsusp_header_init(void) -- cgit v1.1 From c2dd0dae185423fb243b13d490c3fcfaa18ff333 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 8 Oct 2007 13:21:10 -0400 Subject: [PATCH] propagate mode through swsusp_close() Signed-off-by: Al Viro --- kernel/power/disk.c | 2 +- kernel/power/power.h | 2 +- kernel/power/swap.c | 6 +++--- 3 files changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 331f983..c9d7408 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -651,7 +651,7 @@ static int software_resume(void) pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { - swsusp_close(); + swsusp_close(FMODE_READ); goto Done; } diff --git a/kernel/power/power.h b/kernel/power/power.h index acc0c10..46b5ec7 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -153,7 +153,7 @@ extern int swsusp_shrink_memory(void); extern void swsusp_free(void); extern int swsusp_read(unsigned int *flags_p); extern int swsusp_write(unsigned int flags); -extern void swsusp_close(void); +extern void swsusp_close(fmode_t); struct timeval; /* kernel/power/swsusp.c */ diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 7b9d611..178b001 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -426,7 +426,7 @@ int swsusp_write(unsigned int flags) release_swap_writer(&handle); out: - swsusp_close(); + swsusp_close(FMODE_WRITE); return error; } @@ -626,14 +626,14 @@ int swsusp_check(void) * swsusp_close - close swap device. */ -void swsusp_close(void) +void swsusp_close(fmode_t mode) { if (IS_ERR(resume_bdev)) { pr_debug("PM: Image device not initialised\n"); return; } - blkdev_put(resume_bdev, 0); /* move up */ + blkdev_put(resume_bdev, mode); /* move up */ } static int swsusp_header_init(void) -- cgit v1.1 From 572c48921574dbe6dceb958cf965aa962baefde4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 8 Oct 2007 13:24:05 -0400 Subject: [PATCH] sanitize blkdev_get() and friends * get rid of fake struct file/struct dentry in __blkdev_get() * merge __blkdev_get() and do_open() * get rid of flags argument of blkdev_get() Signed-off-by: Al Viro --- kernel/power/swap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 178b001..b7713b5 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -172,7 +172,7 @@ static int swsusp_swap_check(void) /* This is called before saving image */ return res; root_swap = res; - res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR); + res = blkdev_get(resume_bdev, FMODE_WRITE); if (res) return res; -- cgit v1.1 From b6f3b7803a9231eddc36d0a2a6d2d8105ef89344 Mon Sep 17 00:00:00 2001 From: Dean Nelson Date: Sat, 18 Oct 2008 16:06:56 -0700 Subject: genirq: NULL struct irq_desc's member 'name' in dynamic_irq_cleanup() If the member 'name' of the irq_desc structure happens to point to a character string that is resident within a kernel module, problems ensue if that module is rmmod'd (at which time dynamic_irq_cleanup() is called) and then later show_interrupts() is called by someone. It is also not a good thing if the character string resided in kmalloc'd space that has been kfree'd (after having called dynamic_irq_cleanup()). dynamic_irq_cleanup() fails to NULL the 'name' member and show_interrupts() references it on a few architectures (like h8300, sh and x86). Signed-off-by: Dean Nelson Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/irq/chip.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 3de6ea3..10b5092 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -76,6 +76,7 @@ void dynamic_irq_cleanup(unsigned int irq) desc->chip_data = NULL; desc->handle_irq = handle_bad_irq; desc->chip = &no_irq_chip; + desc->name = NULL; spin_unlock_irqrestore(&desc->lock, flags); } -- cgit v1.1 From 5f86515158ca86182c1dbecd546f1848121ba135 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 17 Oct 2008 14:40:30 +0800 Subject: rcupdate: fix bug of rcu_barrier*() current rcu_barrier_bh() is like this: void rcu_barrier_bh(void) { BUG_ON(in_interrupt()); /* Take cpucontrol mutex to protect against CPU hotplug */ mutex_lock(&rcu_barrier_mutex); init_completion(&rcu_barrier_completion); atomic_set(&rcu_barrier_cpu_count, 0); /* * The queueing of callbacks in all CPUs must be atomic with * respect to RCU, otherwise one CPU may queue a callback, * wait for a grace period, decrement barrier count and call * complete(), while other CPUs have not yet queued anything. * So, we need to make sure that grace periods cannot complete * until all the callbacks are queued. */ rcu_read_lock(); on_each_cpu(rcu_barrier_func, (void *)RCU_BARRIER_BH, 1); rcu_read_unlock(); wait_for_completion(&rcu_barrier_completion); mutex_unlock(&rcu_barrier_mutex); } The inconsistency of the code and the comments show a bug here. rcu_read_lock() cannot make sure that "grace periods for RCU_BH cannot complete until all the callbacks are queued". it only make sure that race periods for RCU cannot complete until all the callbacks are queued. so we must use rcu_read_lock_bh() for rcu_barrier_bh(). like this: void rcu_barrier_bh(void) { ...... rcu_read_lock_bh(); on_each_cpu(rcu_barrier_func, (void *)RCU_BARRIER_BH, 1); rcu_read_unlock_bh(); ...... } and also rcu_barrier() rcu_barrier_sched() are implemented like this. it will bring a lot of duplicate code. My patch uses another way to fix this bug, please see the comment of my patch. Thank Paul E. McKenney for he rewrote the comment. Signed-off-by: Lai Jiangshan Reviewed-by: Paul E. McKenney Signed-off-by: Ingo Molnar --- kernel/rcupdate.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 467d594..ad63af8 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -119,18 +119,19 @@ static void _rcu_barrier(enum rcu_barrier type) /* Take cpucontrol mutex to protect against CPU hotplug */ mutex_lock(&rcu_barrier_mutex); init_completion(&rcu_barrier_completion); - atomic_set(&rcu_barrier_cpu_count, 0); /* - * The queueing of callbacks in all CPUs must be atomic with - * respect to RCU, otherwise one CPU may queue a callback, - * wait for a grace period, decrement barrier count and call - * complete(), while other CPUs have not yet queued anything. - * So, we need to make sure that grace periods cannot complete - * until all the callbacks are queued. + * Initialize rcu_barrier_cpu_count to 1, then invoke + * rcu_barrier_func() on each CPU, so that each CPU also has + * incremented rcu_barrier_cpu_count. Only then is it safe to + * decrement rcu_barrier_cpu_count -- otherwise the first CPU + * might complete its grace period before all of the other CPUs + * did their increment, causing this function to return too + * early. */ - rcu_read_lock(); + atomic_set(&rcu_barrier_cpu_count, 1); on_each_cpu(rcu_barrier_func, (void *)type, 1); - rcu_read_unlock(); + if (atomic_dec_and_test(&rcu_barrier_cpu_count)) + complete(&rcu_barrier_completion); wait_for_completion(&rcu_barrier_completion); mutex_unlock(&rcu_barrier_mutex); } -- cgit v1.1 From c4bd822e7b12a9008241d76db45b665f2fef180c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 21 Oct 2008 20:17:35 +0200 Subject: NOHZ: fix thinko in the timer restart code path commit fb02fbc14d17837b4b7b02dbb36142c16a7bf208 (NOHZ: restart tick device from irq_enter()) solves the problem of stale jiffies when long running softirqs happen in a long idle sleep period, but it has a major thinko in it: When the interrupt which came in _is_ the timer interrupt which should expire ts->sched_timer then we cancel and rearm the timer _before_ it gets expired in hrtimer_interrupt() to the next period. That means the call back function is not called. This game can go on for ever :( Prevent this by making sure to only rearm the timer when the expiry time is more than one tick_period away. Otherwise keep it running as it is either already expired or will expiry at the right point to update jiffies. Signed-off-by: Thomas Gleixner Tested-by: Venkatesch Pallipadi --- kernel/time/tick-sched.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 0581c11..727c1ae 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -567,11 +567,21 @@ static void tick_nohz_switch_to_nohz(void) static void tick_nohz_kick_tick(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t delta, now; if (!ts->tick_stopped) return; - tick_nohz_restart(ts, ktime_get()); + /* + * Do not touch the tick device, when the next expiry is either + * already reached or less/equal than the tick period. + */ + now = ktime_get(); + delta = ktime_sub(ts->sched_timer.expires, now); + if (delta.tv64 <= tick_period.tv64) + return; + + tick_nohz_restart(ts, now); } #else -- cgit v1.1 From 5e458cc0f4770eea45d3c07110f01b3a94c72aa5 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:13 -0500 Subject: module: simplify load_module. Linus' recent catch of stack overflow in load_module lead me to look at the code. A couple of helpers to get a section address and get objects from a section can help clean things up a little. (And in case you're wondering, the stack size also dropped from 328 to 284 bytes). Signed-off-by: Rusty Russell --- kernel/module.c | 235 ++++++++++++++++++++++++-------------------------------- 1 file changed, 99 insertions(+), 136 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 0d8d21e..3d25668 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -132,6 +132,29 @@ static unsigned int find_sec(Elf_Ehdr *hdr, return 0; } +/* Find a module section, or NULL. */ +static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs, + const char *secstrings, const char *name) +{ + /* Section 0 has sh_addr 0. */ + return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr; +} + +/* Find a module section, or NULL. Fill in number of "objects" in section. */ +static void *section_objs(Elf_Ehdr *hdr, + Elf_Shdr *sechdrs, + const char *secstrings, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_sec(hdr, sechdrs, secstrings, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = sechdrs[sec].sh_size / object_size; + return (void *)sechdrs[sec].sh_addr; +} + /* Provided by the linker */ extern const struct kernel_symbol __start___ksymtab[]; extern const struct kernel_symbol __stop___ksymtab[]; @@ -1789,32 +1812,20 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ -#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG -static void dynamic_printk_setup(Elf_Shdr *sechdrs, unsigned int verboseindex) +static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num) { - struct mod_debug *debug_info; - unsigned long pos, end; - unsigned int num_verbose; - - pos = sechdrs[verboseindex].sh_addr; - num_verbose = sechdrs[verboseindex].sh_size / - sizeof(struct mod_debug); - end = pos + (num_verbose * sizeof(struct mod_debug)); +#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG + unsigned int i; - for (; pos < end; pos += sizeof(struct mod_debug)) { - debug_info = (struct mod_debug *)pos; - register_dynamic_debug_module(debug_info->modname, - debug_info->type, debug_info->logical_modname, - debug_info->flag_names, debug_info->hash, - debug_info->hash2); + for (i = 0; i < num; i++) { + register_dynamic_debug_module(debug[i].modname, + debug[i].type, + debug[i].logical_modname, + debug[i].flag_names, + debug[i].hash, debug[i].hash2); } -} -#else -static inline void dynamic_printk_setup(Elf_Shdr *sechdrs, - unsigned int verboseindex) -{ -} #endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */ +} static void *module_alloc_update_bounds(unsigned long size) { @@ -1843,37 +1854,14 @@ static noinline struct module *load_module(void __user *umod, unsigned int i; unsigned int symindex = 0; unsigned int strindex = 0; - unsigned int setupindex; - unsigned int exindex; - unsigned int exportindex; - unsigned int modindex; - unsigned int obsparmindex; - unsigned int infoindex; - unsigned int gplindex; - unsigned int crcindex; - unsigned int gplcrcindex; - unsigned int versindex; - unsigned int pcpuindex; - unsigned int gplfutureindex; - unsigned int gplfuturecrcindex; + unsigned int modindex, versindex, infoindex, pcpuindex; unsigned int unwindex = 0; -#ifdef CONFIG_UNUSED_SYMBOLS - unsigned int unusedindex; - unsigned int unusedcrcindex; - unsigned int unusedgplindex; - unsigned int unusedgplcrcindex; -#endif - unsigned int markersindex; - unsigned int markersstringsindex; - unsigned int verboseindex; - unsigned int tracepointsindex; - unsigned int tracepointsstringsindex; - unsigned int mcountindex; + unsigned int num_kp, num_mcount; + struct kernel_param *kp; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ - void *mseg; - struct exception_table_entry *extable; + unsigned long *mseg; mm_segment_t old_fs; DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", @@ -1937,6 +1925,7 @@ static noinline struct module *load_module(void __user *umod, err = -ENOEXEC; goto free_hdr; } + /* This is temporary: point mod into copy of data. */ mod = (void *)sechdrs[modindex].sh_addr; if (symindex == 0) { @@ -1946,22 +1935,6 @@ static noinline struct module *load_module(void __user *umod, goto free_hdr; } - /* Optional sections */ - exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); - gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); - gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future"); - crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab"); - gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl"); - gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future"); -#ifdef CONFIG_UNUSED_SYMBOLS - unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); - unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); - unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused"); - unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); -#endif - setupindex = find_sec(hdr, sechdrs, secstrings, "__param"); - exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table"); - obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm"); versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); @@ -2117,42 +2090,57 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; - /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */ - mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms); - mod->syms = (void *)sechdrs[exportindex].sh_addr; - if (crcindex) - mod->crcs = (void *)sechdrs[crcindex].sh_addr; - mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms); - mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr; - if (gplcrcindex) - mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; - mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size / - sizeof(*mod->gpl_future_syms); - mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr; - if (gplfuturecrcindex) - mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr; + /* Now we've got everything in the final locations, we can + * find optional sections. */ + kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp), + &num_kp); + mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab", + sizeof(*mod->syms), &mod->num_syms); + mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab"); + mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl", + sizeof(*mod->gpl_syms), + &mod->num_gpl_syms); + mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl"); + mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_gpl_future", + sizeof(*mod->gpl_future_syms), + &mod->num_gpl_future_syms); + mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_gpl_future"); #ifdef CONFIG_UNUSED_SYMBOLS - mod->num_unused_syms = sechdrs[unusedindex].sh_size / - sizeof(*mod->unused_syms); - mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / - sizeof(*mod->unused_gpl_syms); - mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr; - if (unusedcrcindex) - mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr; - mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr; - if (unusedgplcrcindex) - mod->unused_gpl_crcs - = (void *)sechdrs[unusedgplcrcindex].sh_addr; + mod->unused_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_unused", + sizeof(*mod->unused_syms), + &mod->num_unused_syms); + mod->unused_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_unused"); + mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_unused_gpl", + sizeof(*mod->unused_gpl_syms), + &mod->num_unused_gpl_syms); + mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_unused_gpl"); +#endif + +#ifdef CONFIG_MARKERS + mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", + sizeof(*mod->markers), &mod->num_markers); +#endif +#ifdef CONFIG_TRACEPOINTS + mod->tracepoints = section_objs(hdr, sechdrs, secstrings, + "__tracepoints", + sizeof(*mod->tracepoints), + &mod->num_tracepoints); #endif #ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !crcindex) - || (mod->num_gpl_syms && !gplcrcindex) - || (mod->num_gpl_future_syms && !gplfuturecrcindex) + if ((mod->num_syms && !mod->crcs) + || (mod->num_gpl_syms && !mod->gpl_crcs) + || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) #ifdef CONFIG_UNUSED_SYMBOLS - || (mod->num_unused_syms && !unusedcrcindex) - || (mod->num_unused_gpl_syms && !unusedgplcrcindex) + || (mod->num_unused_syms && !mod->unused_crcs) + || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) #endif ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); @@ -2161,16 +2149,6 @@ static noinline struct module *load_module(void __user *umod, goto cleanup; } #endif - markersindex = find_sec(hdr, sechdrs, secstrings, "__markers"); - markersstringsindex = find_sec(hdr, sechdrs, secstrings, - "__markers_strings"); - verboseindex = find_sec(hdr, sechdrs, secstrings, "__verbose"); - tracepointsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints"); - tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings, - "__tracepoints_strings"); - - mcountindex = find_sec(hdr, sechdrs, secstrings, - "__mcount_loc"); /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { @@ -2193,28 +2171,16 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; } -#ifdef CONFIG_MARKERS - mod->markers = (void *)sechdrs[markersindex].sh_addr; - mod->num_markers = - sechdrs[markersindex].sh_size / sizeof(*mod->markers); -#endif -#ifdef CONFIG_TRACEPOINTS - mod->tracepoints = (void *)sechdrs[tracepointsindex].sh_addr; - mod->num_tracepoints = - sechdrs[tracepointsindex].sh_size / sizeof(*mod->tracepoints); -#endif - /* Find duplicate symbols */ err = verify_export_symbols(mod); - if (err < 0) goto cleanup; /* Set up and sort exception table */ - mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable); - mod->extable = extable = (void *)sechdrs[exindex].sh_addr; - sort_extable(extable, extable + mod->num_exentries); + mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table", + sizeof(*mod->extable), &mod->num_exentries); + sort_extable(mod->extable, mod->extable + mod->num_exentries); /* Finally, copy percpu area over. */ percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr, @@ -2223,11 +2189,17 @@ static noinline struct module *load_module(void __user *umod, add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); if (!mod->taints) { + struct mod_debug *debug; + unsigned int num_debug; + #ifdef CONFIG_MARKERS marker_update_probe_range(mod->markers, mod->markers + mod->num_markers); #endif - dynamic_printk_setup(sechdrs, verboseindex); + debug = section_objs(hdr, sechdrs, secstrings, "__verbose", + sizeof(*debug), &num_debug); + dynamic_printk_setup(debug, num_debug); + #ifdef CONFIG_TRACEPOINTS tracepoint_update_probe_range(mod->tracepoints, mod->tracepoints + mod->num_tracepoints); @@ -2235,8 +2207,9 @@ static noinline struct module *load_module(void __user *umod, } /* sechdrs[0].sh_size is always zero */ - mseg = (void *)sechdrs[mcountindex].sh_addr; - ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size); + mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc", + sizeof(*mseg), &num_mcount); + ftrace_init_module(mseg, mseg + num_mcount); err = module_finalize(hdr, sechdrs, mod); if (err < 0) @@ -2261,7 +2234,7 @@ static noinline struct module *load_module(void __user *umod, set_fs(old_fs); mod->args = args; - if (obsparmindex) + if (section_addr(hdr, sechdrs, secstrings, "__obsparm")) printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", mod->name); @@ -2270,21 +2243,11 @@ static noinline struct module *load_module(void __user *umod, * strong_try_module_get() will fail. */ stop_machine(__link_module, mod, NULL); - /* Size of section 0 is 0, so this works well if no params */ - err = parse_args(mod->name, mod->args, - (struct kernel_param *) - sechdrs[setupindex].sh_addr, - sechdrs[setupindex].sh_size - / sizeof(struct kernel_param), - NULL); + err = parse_args(mod->name, mod->args, kp, num_kp, NULL); if (err < 0) goto unlink; - err = mod_sysfs_setup(mod, - (struct kernel_param *) - sechdrs[setupindex].sh_addr, - sechdrs[setupindex].sh_size - / sizeof(struct kernel_param)); + err = mod_sysfs_setup(mod, kp, num_kp); if (err < 0) goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); -- cgit v1.1 From d72b37513cdfbd3f53f3d485a8c403cc96d2c95f Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 30 Aug 2008 10:09:00 +0200 Subject: Remove stop_machine during module load v2 Remove stop_machine during module load v2 module loading currently does a stop_machine on each module load to insert the module into the global module lists. Especially on larger systems this can be quite expensive. It does that to handle concurrent lock lessmodule list readers like kallsyms. I don't think stop_machine() is actually needed to insert something into a list though. There are no concurrent writers because the module mutex is taken. And the RCU list functions know how to insert a node into a list with the right memory ordering so that concurrent readers don't go off into the wood. So remove the stop_machine for the module list insert and just do a list_add_rcu() instead. Module removal will still do a stop_machine of course, it needs that for other reasons. v2: Revised readers based on Paul's comments. All readers that only rely on disabled preemption need to be changed to list_for_each_rcu(). Done that. The others are ok because they have the modules mutex. Also added a possible missing preempt disable for print_modules(). [cc Paul McKenney for review. It's not RCU, but quite similar.] Acked-by: Paul E. McKenney Signed-off-by: Rusty Russell --- kernel/module.c | 47 ++++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 25 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 3d25668..c0f1826 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include @@ -63,7 +64,7 @@ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) /* List of modules, protected by module_mutex or preempt_disable - * (add/delete uses stop_machine). */ + * (delete uses stop_machine/add uses RCU list operations). */ static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); @@ -241,7 +242,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) return true; - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { struct symsearch arr[] = { { mod->syms, mod->syms + mod->num_syms, mod->crcs, NOT_GPL_ONLY, false }, @@ -1417,17 +1418,6 @@ static void mod_kobject_remove(struct module *mod) } /* - * link the module with the whole machine is stopped with interrupts off - * - this defends against kallsyms not taking locks - */ -static int __link_module(void *_mod) -{ - struct module *mod = _mod; - list_add(&mod->list, &modules); - return 0; -} - -/* * unlink the module with the whole machine is stopped with interrupts off * - this defends against kallsyms not taking locks */ @@ -2239,9 +2229,13 @@ static noinline struct module *load_module(void __user *umod, mod->name); /* Now sew it into the lists so we can get lockdep and oops - * info during argument parsing. Noone should access us, since - * strong_try_module_get() will fail. */ - stop_machine(__link_module, mod, NULL); + * info during argument parsing. Noone should access us, since + * strong_try_module_get() will fail. + * lockdep/oops can run asynchronous, so use the RCU list insertion + * function to insert in a way safe to concurrent readers. + * The mutex protects against concurrent writers. + */ + list_add_rcu(&mod->list, &modules); err = parse_args(mod->name, mod->args, kp, num_kp, NULL); if (err < 0) @@ -2436,7 +2430,7 @@ const char *module_address_lookup(unsigned long addr, const char *ret = NULL; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { if (modname) @@ -2459,7 +2453,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { const char *sym; @@ -2483,7 +2477,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { const char *sym; @@ -2510,7 +2504,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (symnum < mod->num_symtab) { *value = mod->symtab[symnum].st_value; *type = mod->symtab[symnum].st_info; @@ -2553,7 +2547,7 @@ unsigned long module_kallsyms_lookup_name(const char *name) ret = mod_find_symname(mod, colon+1); *colon = ':'; } else { - list_for_each_entry(mod, &modules, list) + list_for_each_entry_rcu(mod, &modules, list) if ((ret = mod_find_symname(mod, name)) != 0) break; } @@ -2656,7 +2650,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr) struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (mod->num_exentries == 0) continue; @@ -2682,7 +2676,7 @@ int is_module_address(unsigned long addr) preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_core, mod->core_size)) { preempt_enable(); return 1; @@ -2703,7 +2697,7 @@ struct module *__module_text_address(unsigned long addr) if (addr < module_addr_min || addr > module_addr_max) return NULL; - list_for_each_entry(mod, &modules, list) + list_for_each_entry_rcu(mod, &modules, list) if (within(addr, mod->module_init, mod->init_text_size) || within(addr, mod->module_core, mod->core_text_size)) return mod; @@ -2728,8 +2722,11 @@ void print_modules(void) char buf[8]; printk("Modules linked in:"); - list_for_each_entry(mod, &modules, list) + /* Most callers should already have preempt disabled, but make sure */ + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) printk(" %s%s", mod->name, module_flags(mod, buf)); + preempt_enable(); if (last_unloaded_module[0]) printk(" [last unloaded: %s]", last_unloaded_module); printk("\n"); -- cgit v1.1 From 730b69d225259565c705f5f5a11cb1aba69568f1 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:22 -0500 Subject: module: check kernel param length at compile time, not runtime The kparam code tries to handle over-length parameter prefixes at runtime. Not only would I bet this has never been tested, it's not clear that truncating names is a good idea either. So let's check at compile time. We need to move the #define to moduleparam.h to do this, though. Signed-off-by: Rusty Russell --- kernel/params.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index afc46a2..aca07e1 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -585,17 +585,14 @@ static void __init param_sysfs_builtin(void) { struct kernel_param *kp, *kp_begin = NULL; unsigned int i, name_len, count = 0; - char modname[MODULE_NAME_LEN + 1] = ""; + char modname[MODULE_NAME_LEN] = ""; for (i=0; i < __stop___param - __start___param; i++) { char *dot; - size_t max_name_len; kp = &__start___param[i]; - max_name_len = - min_t(size_t, MODULE_NAME_LEN, strlen(kp->name)); - dot = memchr(kp->name, '.', max_name_len); + dot = strchr(kp->name, '.'); if (!dot) { DEBUGP("couldn't find period in first %d characters " "of %s\n", MODULE_NAME_LEN, kp->name); -- cgit v1.1 From 9b473de87209fa86eb421b23386693b461612f30 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:22 -0500 Subject: param: Fix duplicate module prefixes Instead of insisting each new module_param sysfs entry is unique, handle the case where it already exists (for builtin modules). The current code assumes that all identical prefixes are together in the section: true for normal uses, but not necessarily so if someone overrides MODULE_PARAM_PREFIX. More importantly, it's not true with the new "core_param()" code which uses "kernel" as a prefix. This simplifies the caller for the builtin case, at a slight loss of efficiency (we do the lookup every time to see if the directory exists). Signed-off-by: Rusty Russell Cc: Greg Kroah-Hartman --- kernel/params.c | 261 ++++++++++++++++++++++++++++++-------------------------- 1 file changed, 141 insertions(+), 120 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index aca07e1..f27c992a 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -373,6 +373,8 @@ int param_get_string(char *buffer, struct kernel_param *kp) } /* sysfs output in /sys/modules/XYZ/parameters/ */ +#define to_module_attr(n) container_of(n, struct module_attribute, attr); +#define to_module_kobject(n) container_of(n, struct module_kobject, kobj); extern struct kernel_param __start___param[], __stop___param[]; @@ -384,6 +386,7 @@ struct param_attribute struct module_param_attrs { + unsigned int num; struct attribute_group grp; struct param_attribute attrs[0]; }; @@ -434,69 +437,84 @@ static ssize_t param_attr_store(struct module_attribute *mattr, #ifdef CONFIG_SYSFS /* - * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME - * @mk: struct module_kobject (contains parent kobject) - * @kparam: array of struct kernel_param, the actual parameter definitions - * @num_params: number of entries in array - * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules" + * add_sysfs_param - add a parameter to sysfs + * @mk: struct module_kobject + * @kparam: the actual parameter definition to add to sysfs + * @name: name of parameter * - * Create a kobject for a (per-module) group of parameters, and create files - * in sysfs. A pointer to the param_kobject is returned on success, - * NULL if there's no parameter to export, or other ERR_PTR(err). + * Create a kobject if for a (per-module) parameter if mp NULL, and + * create file in sysfs. Returns an error on out of memory. Always cleans up + * if there's an error. */ -static __modinit struct module_param_attrs * -param_sysfs_setup(struct module_kobject *mk, - struct kernel_param *kparam, - unsigned int num_params, - unsigned int name_skip) +static __modinit int add_sysfs_param(struct module_kobject *mk, + struct kernel_param *kp, + const char *name) { - struct module_param_attrs *mp; - unsigned int valid_attrs = 0; - unsigned int i, size[2]; - struct param_attribute *pattr; - struct attribute **gattr; - int err; - - for (i=0; iperm); + + if (!mk->mp) { + num = 0; + attrs = NULL; + } else { + num = mk->mp->num; + attrs = mk->mp->grp.attrs; } - if (!valid_attrs) - return NULL; - - size[0] = ALIGN(sizeof(*mp) + - valid_attrs * sizeof(mp->attrs[0]), - sizeof(mp->grp.attrs[0])); - size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]); - - mp = kzalloc(size[0] + size[1], GFP_KERNEL); - if (!mp) - return ERR_PTR(-ENOMEM); + /* Enlarge. */ + new = krealloc(mk->mp, + sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), + GFP_KERNEL); + if (!new) { + kfree(mk->mp); + err = -ENOMEM; + goto fail; + } + attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); + if (!attrs) { + err = -ENOMEM; + goto fail_free_new; + } - mp->grp.name = "parameters"; - mp->grp.attrs = (void *)mp + size[0]; + /* Sysfs wants everything zeroed. */ + memset(new, 0, sizeof(*new)); + memset(&new->attrs[num], 0, sizeof(new->attrs[num])); + memset(&attrs[num], 0, sizeof(attrs[num])); + new->grp.name = "parameters"; + new->grp.attrs = attrs; + + /* Tack new one on the end. */ + new->attrs[num].param = kp; + new->attrs[num].mattr.show = param_attr_show; + new->attrs[num].mattr.store = param_attr_store; + new->attrs[num].mattr.attr.name = (char *)name; + new->attrs[num].mattr.attr.mode = kp->perm; + new->num = num+1; + + /* Fix up all the pointers, since krealloc can move us */ + for (num = 0; num < new->num; num++) + new->grp.attrs[num] = &new->attrs[num].mattr.attr; + new->grp.attrs[num] = NULL; + + mk->mp = new; + return 0; - pattr = &mp->attrs[0]; - gattr = &mp->grp.attrs[0]; - for (i = 0; i < num_params; i++) { - struct kernel_param *kp = &kparam[i]; - if (kp->perm) { - pattr->param = kp; - pattr->mattr.show = param_attr_show; - pattr->mattr.store = param_attr_store; - pattr->mattr.attr.name = (char *)&kp->name[name_skip]; - pattr->mattr.attr.mode = kp->perm; - *(gattr++) = &(pattr++)->mattr.attr; - } - } - *gattr = NULL; +fail_free_new: + kfree(new); +fail: + mk->mp = NULL; + return err; +} - if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) { - kfree(mp); - return ERR_PTR(err); - } - return mp; +static void free_module_param_attrs(struct module_kobject *mk) +{ + kfree(mk->mp->grp.attrs); + kfree(mk->mp); + mk->mp = NULL; } #ifdef CONFIG_MODULES @@ -506,21 +524,33 @@ param_sysfs_setup(struct module_kobject *mk, * @kparam: module parameters (array) * @num_params: number of module parameters * - * Adds sysfs entries for module parameters, and creates a link from - * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/ + * Adds sysfs entries for module parameters under + * /sys/module/[mod->name]/parameters/ */ int module_param_sysfs_setup(struct module *mod, struct kernel_param *kparam, unsigned int num_params) { - struct module_param_attrs *mp; + int i, err; + bool params = false; + + for (i = 0; i < num_params; i++) { + if (kparam[i].perm == 0) + continue; + err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); + if (err) + return err; + params = true; + } - mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0); - if (IS_ERR(mp)) - return PTR_ERR(mp); + if (!params) + return 0; - mod->param_attrs = mp; - return 0; + /* Create the param group. */ + err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); + if (err) + free_module_param_attrs(&mod->mkobj); + return err; } /* @@ -532,43 +562,55 @@ int module_param_sysfs_setup(struct module *mod, */ void module_param_sysfs_remove(struct module *mod) { - if (mod->param_attrs) { - sysfs_remove_group(&mod->mkobj.kobj, - &mod->param_attrs->grp); + if (mod->mkobj.mp) { + sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); /* We are positive that no one is using any param * attrs at this point. Deallocate immediately. */ - kfree(mod->param_attrs); - mod->param_attrs = NULL; + free_module_param_attrs(&mod->mkobj); } } #endif -/* - * kernel_param_sysfs_setup - wrapper for built-in params support - */ -static void __init kernel_param_sysfs_setup(const char *name, - struct kernel_param *kparam, - unsigned int num_params, - unsigned int name_skip) +static void __init kernel_add_sysfs_param(const char *name, + struct kernel_param *kparam, + unsigned int name_skip) { struct module_kobject *mk; - int ret; + struct kobject *kobj; + int err; - mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); - BUG_ON(!mk); - - mk->mod = THIS_MODULE; - mk->kobj.kset = module_kset; - ret = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name); - if (ret) { - kobject_put(&mk->kobj); - printk(KERN_ERR "Module '%s' failed to be added to sysfs, " - "error number %d\n", name, ret); - printk(KERN_ERR "The system will be unstable now.\n"); - return; + kobj = kset_find_obj(module_kset, name); + if (kobj) { + /* We already have one. Remove params so we can add more. */ + mk = to_module_kobject(kobj); + /* We need to remove it before adding parameters. */ + sysfs_remove_group(&mk->kobj, &mk->mp->grp); + } else { + mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); + BUG_ON(!mk); + + mk->mod = THIS_MODULE; + mk->kobj.kset = module_kset; + err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, + "%s", name); + if (err) { + kobject_put(&mk->kobj); + printk(KERN_ERR "Module '%s' failed add to sysfs, " + "error number %d\n", name, err); + printk(KERN_ERR "The system will be unstable now.\n"); + return; + } + /* So that exit path is even. */ + kobject_get(&mk->kobj); } - param_sysfs_setup(mk, kparam, num_params, name_skip); + + /* These should not fail at boot. */ + err = add_sysfs_param(mk, kparam, kparam->name + name_skip); + BUG_ON(err); + err = sysfs_create_group(&mk->kobj, &mk->mp->grp); + BUG_ON(err); kobject_uevent(&mk->kobj, KOBJ_ADD); + kobject_put(&mk->kobj); } /* @@ -579,18 +621,19 @@ static void __init kernel_param_sysfs_setup(const char *name, * The "module" name (KBUILD_MODNAME) is stored before a dot, the * "parameter" name is stored behind a dot in kernel_param->name. So, * extract the "module" name for all built-in kernel_param-eters, - * and for all who have the same, call kernel_param_sysfs_setup. + * and for all who have the same, call kernel_add_sysfs_param. */ static void __init param_sysfs_builtin(void) { - struct kernel_param *kp, *kp_begin = NULL; - unsigned int i, name_len, count = 0; - char modname[MODULE_NAME_LEN] = ""; + struct kernel_param *kp; + unsigned int name_len; + char modname[MODULE_NAME_LEN]; - for (i=0; i < __stop___param - __start___param; i++) { + for (kp = __start___param; kp < __stop___param; kp++) { char *dot; - kp = &__start___param[i]; + if (kp->perm == 0) + continue; dot = strchr(kp->name, '.'); if (!dot) { @@ -599,37 +642,15 @@ static void __init param_sysfs_builtin(void) continue; } name_len = dot - kp->name; - - /* new kbuild_modname? */ - if (strlen(modname) != name_len - || strncmp(modname, kp->name, name_len) != 0) { - /* add a new kobject for previous kernel_params. */ - if (count) - kernel_param_sysfs_setup(modname, - kp_begin, - count, - strlen(modname)+1); - - strncpy(modname, kp->name, name_len); - modname[name_len] = '\0'; - count = 0; - kp_begin = kp; - } - count++; + strncpy(modname, kp->name, name_len); + modname[name_len] = '\0'; + kernel_add_sysfs_param(modname, kp, name_len+1); } - - /* last kernel_params need to be registered as well */ - if (count) - kernel_param_sysfs_setup(modname, kp_begin, count, - strlen(modname)+1); } /* module-related sysfs stuff */ -#define to_module_attr(n) container_of(n, struct module_attribute, attr); -#define to_module_kobject(n) container_of(n, struct module_kobject, kobj); - static ssize_t module_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) -- cgit v1.1 From 67e67ceaac5bf55dbdceb704ff2d763d438b5373 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:23 -0500 Subject: core_param() for genuinely core kernel parameters There are a lot of one-liner uses of __setup() in the kernel: they're cumbersome and not queryable (definitely not settable) via /sys. Yet it's ugly to simplify them to module_param(), because by default that inserts a prefix of the module name (usually filename). So, introduce a "core_param". The parameter gets no prefix, but appears in /sys/module/kernel/parameters/ (if non-zero perms arg). I thought about using the name "core", but that's more common than "kernel". And if you create a module called "kernel", you will die a horrible death. Signed-off-by: Rusty Russell --- kernel/params.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index f27c992a..b077f1b 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -637,14 +637,14 @@ static void __init param_sysfs_builtin(void) dot = strchr(kp->name, '.'); if (!dot) { - DEBUGP("couldn't find period in first %d characters " - "of %s\n", MODULE_NAME_LEN, kp->name); - continue; + /* This happens for core_param() */ + strcpy(modname, "kernel"); + name_len = 0; + } else { + name_len = dot - kp->name + 1; + strlcpy(modname, kp->name, name_len); } - name_len = dot - kp->name; - strncpy(modname, kp->name, name_len); - modname[name_len] = '\0'; - kernel_add_sysfs_param(modname, kp, name_len+1); + kernel_add_sysfs_param(modname, kp, name_len); } } -- cgit v1.1 From f44dd164f37336f7e17fabf5740698fd10635172 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:24 -0500 Subject: Make panic= and panic_on_oops into core_params This allows them to be examined and set after boot, plus means they actually give errors if they are misused (eg. panic=yes). Signed-off-by: Rusty Russell --- kernel/panic.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/panic.c b/kernel/panic.c index bda561e..6513aac 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -34,13 +34,6 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list); EXPORT_SYMBOL(panic_notifier_list); -static int __init panic_setup(char *str) -{ - panic_timeout = simple_strtoul(str, NULL, 0); - return 1; -} -__setup("panic=", panic_setup); - static long no_blink(long time) { return 0; @@ -218,13 +211,6 @@ void add_taint(unsigned flag) } EXPORT_SYMBOL(add_taint); -static int __init pause_on_oops_setup(char *str) -{ - pause_on_oops = simple_strtoul(str, NULL, 0); - return 1; -} -__setup("pause_on_oops=", pause_on_oops_setup); - static void spin_msec(int msecs) { int i; @@ -384,3 +370,6 @@ void __stack_chk_fail(void) } EXPORT_SYMBOL(__stack_chk_fail); #endif + +core_param(panic, panic_timeout, int, 0644); +core_param(pause_on_oops, pause_on_oops, int, 0644); -- cgit v1.1 From 0d557dc97f4bb501f086a03d0f00b99a7855d794 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 13 Oct 2008 23:50:09 +0200 Subject: workqueue: introduce create_rt_workqueue create_rt_workqueue will create a real time prioritized workqueue. This is needed for the conversion of stop_machine to a workqueue based implementation. This patch adds yet another parameter to __create_workqueue_key to tell it that we want an rt workqueue. However it looks like we rather should have something like "int type" instead of singlethread, freezable and rt. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell Cc: Ingo Molnar --- kernel/workqueue.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 714afad..f928f2a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -62,6 +62,7 @@ struct workqueue_struct { const char *name; int singlethread; int freezeable; /* Freeze threads during suspend */ + int rt; #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; #endif @@ -766,6 +767,7 @@ init_cpu_workqueue(struct workqueue_struct *wq, int cpu) static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) { + struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; struct workqueue_struct *wq = cwq->wq; const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d"; struct task_struct *p; @@ -781,7 +783,8 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) */ if (IS_ERR(p)) return PTR_ERR(p); - + if (cwq->wq->rt) + sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); cwq->thread = p; return 0; @@ -801,6 +804,7 @@ static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) struct workqueue_struct *__create_workqueue_key(const char *name, int singlethread, int freezeable, + int rt, struct lock_class_key *key, const char *lock_name) { @@ -822,6 +826,7 @@ struct workqueue_struct *__create_workqueue_key(const char *name, lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); wq->singlethread = singlethread; wq->freezeable = freezeable; + wq->rt = rt; INIT_LIST_HEAD(&wq->list); if (singlethread) { -- cgit v1.1 From c9583e55fa2b08a230c549bd1e3c0bde6c50d9cc Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 13 Oct 2008 23:50:10 +0200 Subject: stop_machine: use workqueues instead of kernel threads Convert stop_machine to a workqueue based approach. Instead of using kernel threads for stop_machine we now use a an rt workqueue to synchronize all cpus. This has the advantage that all needed per cpu threads are already created when stop_machine gets called. And therefore a call to stop_machine won't fail anymore. This is needed for s390 which needs a mechanism to synchronize all cpus without allocating any memory. As Rusty pointed out free_module() needs a non-failing stop_machine interface as well. As a side effect the stop_machine code gets simplified. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell --- kernel/stop_machine.c | 111 +++++++++++++++++++------------------------------- 1 file changed, 41 insertions(+), 70 deletions(-) (limited to 'kernel') diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index af3c7ce..0e688c6 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -37,9 +37,13 @@ struct stop_machine_data { /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ static unsigned int num_threads; static atomic_t thread_ack; -static struct completion finished; static DEFINE_MUTEX(lock); +static struct workqueue_struct *stop_machine_wq; +static struct stop_machine_data active, idle; +static const cpumask_t *active_cpus; +static void *stop_machine_work; + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ @@ -51,21 +55,25 @@ static void set_state(enum stopmachine_state newstate) /* Last one to ack a state moves to the next state. */ static void ack_state(void) { - if (atomic_dec_and_test(&thread_ack)) { - /* If we're the last one to ack the EXIT, we're finished. */ - if (state == STOPMACHINE_EXIT) - complete(&finished); - else - set_state(state + 1); - } + if (atomic_dec_and_test(&thread_ack)) + set_state(state + 1); } -/* This is the actual thread which stops the CPU. It exits by itself rather - * than waiting for kthread_stop(), because it's easier for hotplug CPU. */ -static int stop_cpu(struct stop_machine_data *smdata) +/* This is the actual function which stops the CPU. It runs + * in the context of a dedicated stopmachine workqueue. */ +static void stop_cpu(struct work_struct *unused) { enum stopmachine_state curstate = STOPMACHINE_NONE; - + struct stop_machine_data *smdata = &idle; + int cpu = smp_processor_id(); + + if (!active_cpus) { + if (cpu == first_cpu(cpu_online_map)) + smdata = &active; + } else { + if (cpu_isset(cpu, *active_cpus)) + smdata = &active; + } /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -90,7 +98,6 @@ static int stop_cpu(struct stop_machine_data *smdata) } while (curstate != STOPMACHINE_EXIT); local_irq_enable(); - do_exit(0); } /* Callback for CPUs which aren't supposed to do anything. */ @@ -101,78 +108,34 @@ static int chill(void *unused) int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { - int i, err; - struct stop_machine_data active, idle; - struct task_struct **threads; + struct work_struct *sm_work; + int i; + /* Set up initial state. */ + mutex_lock(&lock); + num_threads = num_online_cpus(); + active_cpus = cpus; active.fn = fn; active.data = data; active.fnret = 0; idle.fn = chill; idle.data = NULL; - /* This could be too big for stack on large machines. */ - threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL); - if (!threads) - return -ENOMEM; - - /* Set up initial state. */ - mutex_lock(&lock); - init_completion(&finished); - num_threads = num_online_cpus(); set_state(STOPMACHINE_PREPARE); - for_each_online_cpu(i) { - struct stop_machine_data *smdata = &idle; - struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; - - if (!cpus) { - if (i == first_cpu(cpu_online_map)) - smdata = &active; - } else { - if (cpu_isset(i, *cpus)) - smdata = &active; - } - - threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u", - i); - if (IS_ERR(threads[i])) { - err = PTR_ERR(threads[i]); - threads[i] = NULL; - goto kill_threads; - } - - /* Place it onto correct cpu. */ - kthread_bind(threads[i], i); - - /* Make it highest prio. */ - if (sched_setscheduler_nocheck(threads[i], SCHED_FIFO, ¶m)) - BUG(); - } - - /* We've created all the threads. Wake them all: hold this CPU so one + /* Schedule the stop_cpu work on all cpus: hold this CPU so one * doesn't hit this CPU until we're ready. */ get_cpu(); - for_each_online_cpu(i) - wake_up_process(threads[i]); - + for_each_online_cpu(i) { + sm_work = percpu_ptr(stop_machine_work, i); + INIT_WORK(sm_work, stop_cpu); + queue_work_on(i, stop_machine_wq, sm_work); + } /* This will release the thread on our CPU. */ put_cpu(); - wait_for_completion(&finished); + flush_workqueue(stop_machine_wq); mutex_unlock(&lock); - - kfree(threads); - return active.fnret; - -kill_threads: - for_each_online_cpu(i) - if (threads[i]) - kthread_stop(threads[i]); - mutex_unlock(&lock); - - kfree(threads); - return err; } int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) @@ -187,3 +150,11 @@ int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) return ret; } EXPORT_SYMBOL_GPL(stop_machine); + +static int __init stop_machine_init(void) +{ + stop_machine_wq = create_rt_workqueue("kstop"); + stop_machine_work = alloc_percpu(struct work_struct); + return 0; +} +early_initcall(stop_machine_init); -- cgit v1.1 From 8163bcac779f62c6bf847caed9bce905db0693fb Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 22 Oct 2008 10:00:26 -0500 Subject: stop_machine: fix error code handling on multiple cpus Using |= for updating a value which might be updated on several cpus concurrently will not always work since we need to make sure that the update happens atomically. To fix this just use a write if the called function returns an error code on a cpu. We end up writing the error code of an arbitrary cpu if multiple ones fail but that should be sufficient. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell --- kernel/stop_machine.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 0e688c6..8aff79d 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -66,6 +66,7 @@ static void stop_cpu(struct work_struct *unused) enum stopmachine_state curstate = STOPMACHINE_NONE; struct stop_machine_data *smdata = &idle; int cpu = smp_processor_id(); + int err; if (!active_cpus) { if (cpu == first_cpu(cpu_online_map)) @@ -86,9 +87,11 @@ static void stop_cpu(struct work_struct *unused) hard_irq_disable(); break; case STOPMACHINE_RUN: - /* |= allows error detection if functions on - * multiple CPUs. */ - smdata->fnret |= smdata->fn(smdata->data); + /* On multiple CPUs only a single error code + * is needed to tell that something failed. */ + err = smdata->fn(smdata->data); + if (err) + smdata->fnret = err; break; default: break; -- cgit v1.1 From 3786fc710c32b61464c322e5cd0c3d1d34ae72d0 Mon Sep 17 00:00:00 2001 From: roel kluin Date: Tue, 21 Oct 2008 19:49:09 -0400 Subject: irq: make variable static This variable is only used in the source file, so make it static. Signed-off-by: Roel Kluin Signed-off-by: Ingo Molnar --- kernel/irq/proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index fac014a..4d161c70 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -220,7 +220,7 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action) } } -void register_default_affinity_proc(void) +static void register_default_affinity_proc(void) { #ifdef CONFIG_SMP proc_create("irq/default_smp_affinity", 0600, NULL, -- cgit v1.1 From 17d80fd07d35ae1d231b3378ee4f00ace54f9d31 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 21 Oct 2008 16:31:18 +0200 Subject: tracing: create tracers menu MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We seem to have plenty tracers, lets create a menu and not clutter the already cluttered debug menu more. Signed-off-by: Peter Zijlstra Acked-by: Frédéric Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 3533c58..bc535cb 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -29,6 +29,8 @@ config TRACING select STACKTRACE select TRACEPOINTS +menu "Tracers" + config FUNCTION_TRACER bool "Kernel Function Tracer" depends on HAVE_FUNCTION_TRACER @@ -191,3 +193,5 @@ config FTRACE_STARTUP_TEST a series of tests are made to verify that the tracer is functioning properly. It will do tests on all the configured tracers of ftrace. + +endmenu -- cgit v1.1 From 4ce72a2c063a7fa8e42a9435440ae3364115a58d Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 22 Oct 2008 15:25:26 +0800 Subject: sched: add CONFIG_SMP consistency a patch from Henrik Austad did this: >> Do not declare select_task_rq as part of sched_class when CONFIG_SMP is >> not set. Peter observed: > While a proper cleanup, could you do it by re-arranging the methods so > as to not create an additional ifdef? Do not declare select_task_rq and some other methods as part of sched_class when CONFIG_SMP is not set. Also gather those methods to avoid CONFIG_SMP mess. Idea-by: Henrik Austad Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Acked-by: Henrik Austad Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 5 ++--- kernel/sched_idletask.c | 5 ++--- kernel/sched_rt.c | 5 ++--- 3 files changed, 6 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a0aa38b..8de48a5 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1593,9 +1593,6 @@ static const struct sched_class fair_sched_class = { .enqueue_task = enqueue_task_fair, .dequeue_task = dequeue_task_fair, .yield_task = yield_task_fair, -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_fair, -#endif /* CONFIG_SMP */ .check_preempt_curr = check_preempt_wakeup, @@ -1603,6 +1600,8 @@ static const struct sched_class fair_sched_class = { .put_prev_task = put_prev_task_fair, #ifdef CONFIG_SMP + .select_task_rq = select_task_rq_fair, + .load_balance = load_balance_fair, .move_one_task = move_one_task_fair, #endif diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index dec4cca..8a21a2e 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -105,9 +105,6 @@ static const struct sched_class idle_sched_class = { /* dequeue is not valid, we print a debug message there: */ .dequeue_task = dequeue_task_idle, -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_idle, -#endif /* CONFIG_SMP */ .check_preempt_curr = check_preempt_curr_idle, @@ -115,6 +112,8 @@ static const struct sched_class idle_sched_class = { .put_prev_task = put_prev_task_idle, #ifdef CONFIG_SMP + .select_task_rq = select_task_rq_idle, + .load_balance = load_balance_idle, .move_one_task = move_one_task_idle, #endif diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index cdf5740..c9aa5be 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1502,9 +1502,6 @@ static const struct sched_class rt_sched_class = { .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, .yield_task = yield_task_rt, -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_rt, -#endif /* CONFIG_SMP */ .check_preempt_curr = check_preempt_curr_rt, @@ -1512,6 +1509,8 @@ static const struct sched_class rt_sched_class = { .put_prev_task = put_prev_task_rt, #ifdef CONFIG_SMP + .select_task_rq = select_task_rq_rt, + .load_balance = load_balance_rt, .move_one_task = move_one_task_rt, .set_cpus_allowed = set_cpus_allowed_rt, -- cgit v1.1 From 6ae2a0765ab764da11cc305058ee5333810228f4 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 13 Oct 2008 10:22:06 -0400 Subject: ring-buffer: fix free page The pages of a buffer was originally pointing to the page struct, it now points to the page address. The freeing of the page still uses the page frame free "__free_page" instead of the correct free_page to the address. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 94af1fe..091aeef 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -130,7 +130,7 @@ struct buffer_page { static inline void free_buffer_page(struct buffer_page *bpage) { if (bpage->page) - __free_page(bpage->page); + free_page((unsigned long)bpage->page); kfree(bpage); } -- cgit v1.1 From 98bc993f99e51467057ef699e47fec020f24d233 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 Aug 2008 01:06:21 -0400 Subject: [PATCH] get rid of nameidata in audit_tree Signed-off-by: Al Viro --- kernel/audit_tree.c | 48 ++++++++++++++++++++++++------------------------ 1 file changed, 24 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index f7921a2..8ba0e0d 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -532,7 +532,7 @@ void audit_trim_trees(void) list_add(&cursor, &tree_list); while (cursor.next != &tree_list) { struct audit_tree *tree; - struct nameidata nd; + struct path path; struct vfsmount *root_mnt; struct node *node; struct list_head list; @@ -544,12 +544,12 @@ void audit_trim_trees(void) list_add(&cursor, &tree->list); mutex_unlock(&audit_filter_mutex); - err = path_lookup(tree->pathname, 0, &nd); + err = kern_path(tree->pathname, 0, &path); if (err) goto skip_it; - root_mnt = collect_mounts(nd.path.mnt, nd.path.dentry); - path_put(&nd.path); + root_mnt = collect_mounts(path.mnt, path.dentry); + path_put(&path); if (!root_mnt) goto skip_it; @@ -580,19 +580,19 @@ skip_it: } static int is_under(struct vfsmount *mnt, struct dentry *dentry, - struct nameidata *nd) + struct path *path) { - if (mnt != nd->path.mnt) { + if (mnt != path->mnt) { for (;;) { if (mnt->mnt_parent == mnt) return 0; - if (mnt->mnt_parent == nd->path.mnt) + if (mnt->mnt_parent == path->mnt) break; mnt = mnt->mnt_parent; } dentry = mnt->mnt_mountpoint; } - return is_subdir(dentry, nd->path.dentry); + return is_subdir(dentry, path->dentry); } int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) @@ -618,7 +618,7 @@ void audit_put_tree(struct audit_tree *tree) int audit_add_tree_rule(struct audit_krule *rule) { struct audit_tree *seed = rule->tree, *tree; - struct nameidata nd; + struct path path; struct vfsmount *mnt, *p; struct list_head list; int err; @@ -637,11 +637,11 @@ int audit_add_tree_rule(struct audit_krule *rule) /* do not set rule->tree yet */ mutex_unlock(&audit_filter_mutex); - err = path_lookup(tree->pathname, 0, &nd); + err = kern_path(tree->pathname, 0, &path); if (err) goto Err; - mnt = collect_mounts(nd.path.mnt, nd.path.dentry); - path_put(&nd.path); + mnt = collect_mounts(path.mnt, path.dentry); + path_put(&path); if (!mnt) { err = -ENOMEM; goto Err; @@ -690,29 +690,29 @@ int audit_tag_tree(char *old, char *new) { struct list_head cursor, barrier; int failed = 0; - struct nameidata nd; + struct path path; struct vfsmount *tagged; struct list_head list; struct vfsmount *mnt; struct dentry *dentry; int err; - err = path_lookup(new, 0, &nd); + err = kern_path(new, 0, &path); if (err) return err; - tagged = collect_mounts(nd.path.mnt, nd.path.dentry); - path_put(&nd.path); + tagged = collect_mounts(path.mnt, path.dentry); + path_put(&path); if (!tagged) return -ENOMEM; - err = path_lookup(old, 0, &nd); + err = kern_path(old, 0, &path); if (err) { drop_collected_mounts(tagged); return err; } - mnt = mntget(nd.path.mnt); - dentry = dget(nd.path.dentry); - path_put(&nd.path); + mnt = mntget(path.mnt); + dentry = dget(path.dentry); + path_put(&path); if (dentry == tagged->mnt_root && dentry == mnt->mnt_root) follow_up(&mnt, &dentry); @@ -733,7 +733,7 @@ int audit_tag_tree(char *old, char *new) list_add(&cursor, &tree->list); mutex_unlock(&audit_filter_mutex); - err = path_lookup(tree->pathname, 0, &nd); + err = kern_path(tree->pathname, 0, &path); if (err) { put_tree(tree); mutex_lock(&audit_filter_mutex); @@ -741,15 +741,15 @@ int audit_tag_tree(char *old, char *new) } spin_lock(&vfsmount_lock); - if (!is_under(mnt, dentry, &nd)) { + if (!is_under(mnt, dentry, &path)) { spin_unlock(&vfsmount_lock); - path_put(&nd.path); + path_put(&path); put_tree(tree); mutex_lock(&audit_filter_mutex); continue; } spin_unlock(&vfsmount_lock); - path_put(&nd.path); + path_put(&path); list_for_each_entry(p, &list, mnt_list) { failed = tag_chunk(p->mnt_root->d_inode, tree); -- cgit v1.1 From 6e62775ece1c83a84d86df44cfd8ea3e6c96ce23 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Sat, 4 Oct 2008 14:28:09 +0400 Subject: proc: move /proc/execdomains to kernel/exec_domain.c Signed-off-by: Alexey Dobriyan --- kernel/exec_domain.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index 0d407e8..0511716 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -12,7 +12,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -173,20 +175,39 @@ __set_personality(u_long personality) return 0; } -int -get_exec_domain_list(char *page) +#ifdef CONFIG_PROC_FS +static int execdomains_proc_show(struct seq_file *m, void *v) { struct exec_domain *ep; - int len = 0; read_lock(&exec_domains_lock); - for (ep = exec_domains; ep && len < PAGE_SIZE - 80; ep = ep->next) - len += sprintf(page + len, "%d-%d\t%-16s\t[%s]\n", + for (ep = exec_domains; ep; ep = ep->next) + seq_printf(m, "%d-%d\t%-16s\t[%s]\n", ep->pers_low, ep->pers_high, ep->name, module_name(ep->module)); read_unlock(&exec_domains_lock); - return (len); + return 0; +} + +static int execdomains_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, execdomains_proc_show, NULL); +} + +static const struct file_operations execdomains_proc_fops = { + .open = execdomains_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init proc_execdomains_init(void) +{ + proc_create("execdomains", 0, NULL, &execdomains_proc_fops); + return 0; } +module_init(proc_execdomains_init); +#endif asmlinkage long sys_personality(u_long personality) -- cgit v1.1 From 593eb8a2d63e95772a5f22d746f18a997c5ee463 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:32:59 -0400 Subject: ftrace: return error on failed modified text. Have the ftrace_modify_code return error values: -EFAULT on error of reading the address -EINVAL if what is read does not match what it expected -EPERM if the write fails to update after a successful match. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 1f54a94..b2de8de 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -596,22 +596,22 @@ ftrace_code_disable(struct dyn_ftrace *rec) { unsigned long ip; unsigned char *nop, *call; - int failed; + int ret; ip = rec->ip; nop = ftrace_nop_replace(); call = ftrace_call_replace(ip, mcount_addr); - failed = ftrace_modify_code(ip, call, nop); - if (failed) { - switch (failed) { - case 1: + ret = ftrace_modify_code(ip, call, nop); + if (ret) { + switch (ret) { + case -EFAULT: WARN_ON_ONCE(1); pr_info("ftrace faulted on modifying "); print_ip_sym(ip); break; - case 2: + case -EINVAL: WARN_ON_ONCE(1); pr_info("ftrace failed to modify "); print_ip_sym(ip); @@ -620,6 +620,15 @@ ftrace_code_disable(struct dyn_ftrace *rec) print_ip_ins(" replace: ", nop); printk(KERN_CONT "\n"); break; + case -EPERM: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on writing "); + print_ip_sym(ip); + break; + default: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on unknown error "); + print_ip_sym(ip); } rec->flags |= FTRACE_FL_FAILED; -- cgit v1.1 From 81adbdc029ecc416d56563e7f159100181dd711d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:02 -0400 Subject: ftrace: only have ftrace_kill atomic When an anomaly is detected, we need a way to completely disable ftrace. Right now we have two functions: ftrace_kill and ftrace_kill_atomic. The ftrace_kill tries to do it in a "nice" way by converting everything back to a nop. The "nice" way is dangerous itself, so this patch removes it and only has the "atomic" version, which is all that is needed. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 42 ++---------------------------------------- kernel/trace/trace.c | 2 +- 2 files changed, 3 insertions(+), 41 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b2de8de..93245ae 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1549,22 +1549,6 @@ int ftrace_force_update(void) return ret; } -static void ftrace_force_shutdown(void) -{ - struct task_struct *task; - int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; - - mutex_lock(&ftraced_lock); - task = ftraced_task; - ftraced_task = NULL; - ftraced_suspend = -1; - ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); - - if (task) - kthread_stop(task); -} - static __init int ftrace_init_debugfs(void) { struct dentry *d_tracer; @@ -1795,17 +1779,16 @@ core_initcall(ftrace_dynamic_init); # define ftrace_shutdown() do { } while (0) # define ftrace_startup_sysctl() do { } while (0) # define ftrace_shutdown_sysctl() do { } while (0) -# define ftrace_force_shutdown() do { } while (0) #endif /* CONFIG_DYNAMIC_FTRACE */ /** - * ftrace_kill_atomic - kill ftrace from critical sections + * ftrace_kill - kill ftrace * * This function should be used by panic code. It stops ftrace * but in a not so nice way. If you need to simply kill ftrace * from a non-atomic section, use ftrace_kill. */ -void ftrace_kill_atomic(void) +void ftrace_kill(void) { ftrace_disabled = 1; ftrace_enabled = 0; @@ -1816,27 +1799,6 @@ void ftrace_kill_atomic(void) } /** - * ftrace_kill - totally shutdown ftrace - * - * This is a safety measure. If something was detected that seems - * wrong, calling this function will keep ftrace from doing - * any more modifications, and updates. - * used when something went wrong. - */ -void ftrace_kill(void) -{ - mutex_lock(&ftrace_sysctl_lock); - ftrace_disabled = 1; - ftrace_enabled = 0; - - clear_ftrace_function(); - mutex_unlock(&ftrace_sysctl_lock); - - /* Try to totally disable ftrace */ - ftrace_force_shutdown(); -} - -/** * register_ftrace_function - register a function for profiling * @ops - ops structure that holds the function for profiling. * diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index aeb2f25..333a516 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3097,7 +3097,7 @@ void ftrace_dump(void) dump_ran = 1; /* No turning back! */ - ftrace_kill_atomic(); + ftrace_kill(); for_each_tracing_cpu(cpu) { atomic_inc(&global_trace.data[cpu]->disabled); -- cgit v1.1 From 6912896e994ddaf06cc0f6d3f2098bc4b59bdd84 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:03 -0400 Subject: ftrace: add ftrace warn on to disable ftrace Add ftrace warn on to disable ftrace as well as report a warning. [ Thanks to Andrew Morton for suggesting using the WARN_ON return value ] Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 93245ae..b08996c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -32,6 +32,18 @@ #include "trace.h" +#define FTRACE_WARN_ON(cond) \ + do { \ + if (WARN_ON(cond)) \ + ftrace_kill(); \ + } while (0) + +#define FTRACE_WARN_ON_ONCE(cond) \ + do { \ + if (WARN_ON_ONCE(cond)) \ + ftrace_kill(); \ + } while (0) + /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; @@ -363,10 +375,8 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) rec = ftrace_free_records; if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); ftrace_free_records = NULL; - ftrace_disabled = 1; - ftrace_enabled = 0; return NULL; } @@ -415,7 +425,7 @@ ftrace_record_ip(unsigned long ip) key = hash_long(ip, FTRACE_HASHBITS); - WARN_ON_ONCE(key >= FTRACE_HASHSIZE); + FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); if (ftrace_ip_in_hash(ip, key)) goto out; @@ -607,12 +617,12 @@ ftrace_code_disable(struct dyn_ftrace *rec) if (ret) { switch (ret) { case -EFAULT: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on modifying "); print_ip_sym(ip); break; case -EINVAL: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace failed to modify "); print_ip_sym(ip); print_ip_ins(" expected: ", call); @@ -621,12 +631,12 @@ ftrace_code_disable(struct dyn_ftrace *rec) printk(KERN_CONT "\n"); break; case -EPERM: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on writing "); print_ip_sym(ip); break; default: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on unknown error "); print_ip_sym(ip); } @@ -1722,8 +1732,7 @@ static int ftraced(void *ignore) ftrace_update_cnt != 1 ? "s" : "", ftrace_update_tot_cnt, usecs, usecs != 1 ? "s" : ""); - ftrace_disabled = 1; - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); } } mutex_unlock(&ftraced_lock); -- cgit v1.1 From cb7be3b2fc2cf089ee52b16f0fd9ebb29e9944e1 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:05 -0400 Subject: ftrace: remove daemon The ftrace daemon is complex and error prone. This patch strips it out of the code. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 322 ++++-------------------------------------- kernel/trace/trace_selftest.c | 14 -- 2 files changed, 28 insertions(+), 308 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b08996c..e758cab 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -165,25 +165,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) } #ifdef CONFIG_DYNAMIC_FTRACE - #ifndef CONFIG_FTRACE_MCOUNT_RECORD -/* - * The hash lock is only needed when the recording of the mcount - * callers are dynamic. That is, by the caller themselves and - * not recorded via the compilation. - */ -static DEFINE_SPINLOCK(ftrace_hash_lock); -#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) -#define ftrace_hash_unlock(flags) \ - spin_unlock_irqrestore(&ftrace_hash_lock, flags) -static void ftrace_release_hash(unsigned long start, unsigned long end); -#else -/* This is protected via the ftrace_lock with MCOUNT_RECORD. */ -#define ftrace_hash_lock(flags) do { (void)(flags); } while (0) -#define ftrace_hash_unlock(flags) do { } while(0) -static inline void ftrace_release_hash(unsigned long start, unsigned long end) -{ -} +# error Dynamic ftrace depends on MCOUNT_RECORD #endif /* @@ -194,8 +177,6 @@ static inline void ftrace_release_hash(unsigned long start, unsigned long end) */ static unsigned long mcount_addr = MCOUNT_ADDR; -static struct task_struct *ftraced_task; - enum { FTRACE_ENABLE_CALLS = (1 << 0), FTRACE_DISABLE_CALLS = (1 << 1), @@ -212,7 +193,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); -static DEFINE_MUTEX(ftraced_lock); static DEFINE_MUTEX(ftrace_regex_lock); struct ftrace_page { @@ -230,10 +210,6 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static int ftraced_trigger; -static int ftraced_suspend; -static int ftraced_stop; - static int ftrace_record_suspend; static struct dyn_ftrace *ftrace_free_records; @@ -398,7 +374,6 @@ static void ftrace_record_ip(unsigned long ip) { struct dyn_ftrace *node; - unsigned long flags; unsigned long key; int resched; int cpu; @@ -430,24 +405,18 @@ ftrace_record_ip(unsigned long ip) if (ftrace_ip_in_hash(ip, key)) goto out; - ftrace_hash_lock(flags); - /* This ip may have hit the hash before the lock */ if (ftrace_ip_in_hash(ip, key)) - goto out_unlock; + goto out; node = ftrace_alloc_dyn_node(ip); if (!node) - goto out_unlock; + goto out; node->ip = ip; ftrace_add_hash(node, key); - ftraced_trigger = 1; - - out_unlock: - ftrace_hash_unlock(flags); out: per_cpu(ftrace_shutdown_disable_cpu, cpu)--; @@ -647,7 +616,7 @@ ftrace_code_disable(struct dyn_ftrace *rec) return 1; } -static int __ftrace_update_code(void *ignore); +static int ftrace_update_code(void *ignore); static int __ftrace_modify_code(void *data) { @@ -659,7 +628,7 @@ static int __ftrace_modify_code(void *data) * Update any recorded ips now that we have the * machine stopped */ - __ftrace_update_code(NULL); + ftrace_update_code(NULL); ftrace_replace_code(1); tracing_on = 1; } else if (*command & FTRACE_DISABLE_CALLS) { @@ -686,26 +655,9 @@ static void ftrace_run_update_code(int command) stop_machine(__ftrace_modify_code, &command, NULL); } -void ftrace_disable_daemon(void) -{ - /* Stop the daemon from calling kstop_machine */ - mutex_lock(&ftraced_lock); - ftraced_stop = 1; - mutex_unlock(&ftraced_lock); - - ftrace_force_update(); -} - -void ftrace_enable_daemon(void) -{ - mutex_lock(&ftraced_lock); - ftraced_stop = 0; - mutex_unlock(&ftraced_lock); - - ftrace_force_update(); -} - static ftrace_func_t saved_ftrace_func; +static int ftrace_start; +static DEFINE_MUTEX(ftrace_start_lock); static void ftrace_startup(void) { @@ -714,9 +666,9 @@ static void ftrace_startup(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - ftraced_suspend++; - if (ftraced_suspend == 1) + mutex_lock(&ftrace_start_lock); + ftrace_start++; + if (ftrace_start == 1) command |= FTRACE_ENABLE_CALLS; if (saved_ftrace_func != ftrace_trace_function) { @@ -729,7 +681,7 @@ static void ftrace_startup(void) ftrace_run_update_code(command); out: - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_shutdown(void) @@ -739,9 +691,9 @@ static void ftrace_shutdown(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - ftraced_suspend--; - if (!ftraced_suspend) + mutex_lock(&ftrace_start_lock); + ftrace_start--; + if (!ftrace_start) command |= FTRACE_DISABLE_CALLS; if (saved_ftrace_func != ftrace_trace_function) { @@ -754,7 +706,7 @@ static void ftrace_shutdown(void) ftrace_run_update_code(command); out: - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_startup_sysctl(void) @@ -764,15 +716,15 @@ static void ftrace_startup_sysctl(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); + mutex_lock(&ftrace_start_lock); /* Force update next time */ saved_ftrace_func = NULL; - /* ftraced_suspend is true if we want ftrace running */ - if (ftraced_suspend) + /* ftrace_start is true if we want ftrace running */ + if (ftrace_start) command |= FTRACE_ENABLE_CALLS; ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_shutdown_sysctl(void) @@ -782,20 +734,20 @@ static void ftrace_shutdown_sysctl(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - /* ftraced_suspend is true if ftrace is running */ - if (ftraced_suspend) + mutex_lock(&ftrace_start_lock); + /* ftrace_start is true if ftrace is running */ + if (ftrace_start) command |= FTRACE_DISABLE_CALLS; ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static cycle_t ftrace_update_time; static unsigned long ftrace_update_cnt; unsigned long ftrace_update_tot_cnt; -static int __ftrace_update_code(void *ignore) +static int ftrace_update_code(void *ignore) { int i, save_ftrace_enabled; cycle_t start, stop; @@ -869,7 +821,6 @@ static int __ftrace_update_code(void *ignore) stop = ftrace_now(raw_smp_processor_id()); ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; - ftraced_trigger = 0; ftrace_enabled = save_ftrace_enabled; ftrace_record_suspend--; @@ -877,17 +828,6 @@ static int __ftrace_update_code(void *ignore) return 0; } -static int ftrace_update_code(void) -{ - if (unlikely(ftrace_disabled) || - !ftrace_enabled || !ftraced_trigger) - return 0; - - stop_machine(__ftrace_update_code, NULL, NULL); - - return 1; -} - static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) { struct ftrace_page *pg; @@ -1425,10 +1365,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) } mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (iter->filtered && ftraced_suspend && ftrace_enabled) + mutex_lock(&ftrace_start_lock); + if (iter->filtered && ftrace_start && ftrace_enabled) ftrace_run_update_code(FTRACE_ENABLE_CALLS); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); mutex_unlock(&ftrace_sysctl_lock); kfree(iter); @@ -1448,55 +1388,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file) return ftrace_regex_release(inode, file, 0); } -static ssize_t -ftraced_read(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - /* don't worry about races */ - char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; - int r = strlen(buf); - - return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); -} - -static ssize_t -ftraced_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[64]; - long val; - int ret; - - if (cnt >= sizeof(buf)) - return -EINVAL; - - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - - if (strncmp(buf, "enable", 6) == 0) - val = 1; - else if (strncmp(buf, "disable", 7) == 0) - val = 0; - else { - buf[cnt] = 0; - - ret = strict_strtoul(buf, 10, &val); - if (ret < 0) - return ret; - - val = !!val; - } - - if (val) - ftrace_enable_daemon(); - else - ftrace_disable_daemon(); - - filp->f_pos += cnt; - - return cnt; -} - static struct file_operations ftrace_avail_fops = { .open = ftrace_avail_open, .read = seq_read, @@ -1527,38 +1418,6 @@ static struct file_operations ftrace_notrace_fops = { .release = ftrace_notrace_release, }; -static struct file_operations ftraced_fops = { - .open = tracing_open_generic, - .read = ftraced_read, - .write = ftraced_write, -}; - -/** - * ftrace_force_update - force an update to all recording ftrace functions - */ -int ftrace_force_update(void) -{ - int ret = 0; - - if (unlikely(ftrace_disabled)) - return -ENODEV; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - - /* - * If ftraced_trigger is not set, then there is nothing - * to update. - */ - if (ftraced_trigger && !ftrace_update_code()) - ret = -EBUSY; - - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - return ret; -} - static __init int ftrace_init_debugfs(void) { struct dentry *d_tracer; @@ -1589,17 +1448,11 @@ static __init int ftrace_init_debugfs(void) pr_warning("Could not create debugfs " "'set_ftrace_notrace' entry\n"); - entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, - NULL, &ftraced_fops); - if (!entry) - pr_warning("Could not create debugfs " - "'ftraced_enabled' entry\n"); return 0; } fs_initcall(ftrace_init_debugfs); -#ifdef CONFIG_FTRACE_MCOUNT_RECORD static int ftrace_convert_nops(unsigned long *start, unsigned long *end) { @@ -1619,7 +1472,7 @@ static int ftrace_convert_nops(unsigned long *start, /* p is ignored */ local_irq_save(flags); - __ftrace_update_code(p); + ftrace_update_code(p); local_irq_restore(flags); return 0; @@ -1666,122 +1519,6 @@ void __init ftrace_init(void) failed: ftrace_disabled = 1; } -#else /* CONFIG_FTRACE_MCOUNT_RECORD */ - -static void ftrace_release_hash(unsigned long start, unsigned long end) -{ - struct dyn_ftrace *rec; - struct hlist_node *t, *n; - struct hlist_head *head, temp_list; - unsigned long flags; - int i, cpu; - - preempt_disable_notrace(); - - /* disable incase we call something that calls mcount */ - cpu = raw_smp_processor_id(); - per_cpu(ftrace_shutdown_disable_cpu, cpu)++; - - ftrace_hash_lock(flags); - - for (i = 0; i < FTRACE_HASHSIZE; i++) { - INIT_HLIST_HEAD(&temp_list); - head = &ftrace_hash[i]; - - /* all CPUS are stopped, we are safe to modify code */ - hlist_for_each_entry_safe(rec, t, n, head, node) { - if (rec->flags & FTRACE_FL_FREE) - continue; - - if ((rec->ip >= start) && (rec->ip < end)) - ftrace_free_rec(rec); - } - } - - ftrace_hash_unlock(flags); - - per_cpu(ftrace_shutdown_disable_cpu, cpu)--; - preempt_enable_notrace(); - -} - -static int ftraced(void *ignore) -{ - unsigned long usecs; - - while (!kthread_should_stop()) { - - set_current_state(TASK_INTERRUPTIBLE); - - /* check once a second */ - schedule_timeout(HZ); - - if (unlikely(ftrace_disabled)) - continue; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (!ftraced_suspend && !ftraced_stop && - ftrace_update_code()) { - usecs = nsecs_to_usecs(ftrace_update_time); - if (ftrace_update_tot_cnt > 100000) { - ftrace_update_tot_cnt = 0; - pr_info("hm, dftrace overflow: %lu change%s" - " (%lu total) in %lu usec%s\n", - ftrace_update_cnt, - ftrace_update_cnt != 1 ? "s" : "", - ftrace_update_tot_cnt, - usecs, usecs != 1 ? "s" : ""); - FTRACE_WARN_ON_ONCE(1); - } - } - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - ftrace_shutdown_replenish(); - } - __set_current_state(TASK_RUNNING); - return 0; -} - -static int __init ftrace_dynamic_init(void) -{ - struct task_struct *p; - unsigned long addr; - int ret; - - addr = (unsigned long)ftrace_record_ip; - - stop_machine(ftrace_dyn_arch_init, &addr, NULL); - - /* ftrace_dyn_arch_init places the return code in addr */ - if (addr) { - ret = (int)addr; - goto failed; - } - - ret = ftrace_dyn_table_alloc(NR_TO_INIT); - if (ret) - goto failed; - - p = kthread_run(ftraced, NULL, "ftraced"); - if (IS_ERR(p)) { - ret = -1; - goto failed; - } - - last_ftrace_enabled = ftrace_enabled = 1; - ftraced_task = p; - - return 0; - - failed: - ftrace_disabled = 1; - return ret; -} - -core_initcall(ftrace_dynamic_init); -#endif /* CONFIG_FTRACE_MCOUNT_RECORD */ #else # define ftrace_startup() do { } while (0) @@ -1801,9 +1538,6 @@ void ftrace_kill(void) { ftrace_disabled = 1; ftrace_enabled = 0; -#ifdef CONFIG_DYNAMIC_FTRACE - ftraced_suspend = -1; -#endif clear_ftrace_function(); } diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 95815d2..90bc752 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -99,13 +99,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* passed in by parameter to fool gcc from optimizing */ func(); - /* update the records */ - ret = ftrace_force_update(); - if (ret) { - printk(KERN_CONT ".. ftraced failed .. "); - return ret; - } - /* * Some archs *cough*PowerPC*cough* add charachters to the * start of the function names. We simply put a '*' to @@ -183,13 +176,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* make sure msleep has been recorded */ msleep(1); - /* force the recorded functions to be traced */ - ret = ftrace_force_update(); - if (ret) { - printk(KERN_CONT ".. ftraced failed .. "); - return ret; - } - /* start the tracing */ ftrace_enabled = 1; tracer_enabled = 1; -- cgit v1.1 From 4d296c24326783bff1282ac72f310d8bac8df413 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:06 -0400 Subject: ftrace: remove mcount set The arch dependent function ftrace_mcount_set was only used by the daemon start up code. This patch removes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index e758cab..226fd91 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -620,7 +620,6 @@ static int ftrace_update_code(void *ignore); static int __ftrace_modify_code(void *data) { - unsigned long addr; int *command = data; if (*command & FTRACE_ENABLE_CALLS) { @@ -639,14 +638,6 @@ static int __ftrace_modify_code(void *data) if (*command & FTRACE_UPDATE_TRACE_FUNC) ftrace_update_ftrace_func(ftrace_trace_function); - if (*command & FTRACE_ENABLE_MCOUNT) { - addr = (unsigned long)ftrace_record_ip; - ftrace_mcount_set(&addr); - } else if (*command & FTRACE_DISABLE_MCOUNT) { - addr = (unsigned long)ftrace_stub; - ftrace_mcount_set(&addr); - } - return 0; } -- cgit v1.1 From 08f5ac906d2c0faf96d608c54a0b03177376da8d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:07 -0400 Subject: ftrace: remove ftrace hash The ftrace hash was used by the ftrace_daemon code. The record ip function would place the calling address (ip) into the hash. The daemon would later read the hash and modify that code. The hash complicates the code. This patch removes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 243 ++++++++------------------------------------------ kernel/trace/trace.c | 3 - 2 files changed, 35 insertions(+), 211 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 226fd91..07762c0 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include @@ -189,9 +188,7 @@ static int ftrace_filtered; static int tracing_on; static int frozen_record_count; -static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; - -static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); +static LIST_HEAD(ftrace_new_addrs); static DEFINE_MUTEX(ftrace_regex_lock); @@ -210,8 +207,6 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static int ftrace_record_suspend; - static struct dyn_ftrace *ftrace_free_records; @@ -242,72 +237,6 @@ static inline int record_frozen(struct dyn_ftrace *rec) # define record_frozen(rec) ({ 0; }) #endif /* CONFIG_KPROBES */ -int skip_trace(unsigned long ip) -{ - unsigned long fl; - struct dyn_ftrace *rec; - struct hlist_node *t; - struct hlist_head *head; - - if (frozen_record_count == 0) - return 0; - - head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; - hlist_for_each_entry_rcu(rec, t, head, node) { - if (rec->ip == ip) { - if (record_frozen(rec)) { - if (rec->flags & FTRACE_FL_FAILED) - return 1; - - if (!(rec->flags & FTRACE_FL_CONVERTED)) - return 1; - - if (!tracing_on || !ftrace_enabled) - return 1; - - if (ftrace_filtered) { - fl = rec->flags & (FTRACE_FL_FILTER | - FTRACE_FL_NOTRACE); - if (!fl || (fl & FTRACE_FL_NOTRACE)) - return 1; - } - } - break; - } - } - - return 0; -} - -static inline int -ftrace_ip_in_hash(unsigned long ip, unsigned long key) -{ - struct dyn_ftrace *p; - struct hlist_node *t; - int found = 0; - - hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { - if (p->ip == ip) { - found = 1; - break; - } - } - - return found; -} - -static inline void -ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) -{ - hlist_add_head_rcu(&node->node, &ftrace_hash[key]); -} - -/* called from kstop_machine */ -static inline void ftrace_del_hash(struct dyn_ftrace *node) -{ - hlist_del(&node->node); -} - static void ftrace_free_rec(struct dyn_ftrace *rec) { rec->ip = (unsigned long)ftrace_free_records; @@ -362,69 +291,36 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) } if (ftrace_pages->index == ENTRIES_PER_PAGE) { - if (!ftrace_pages->next) - return NULL; + if (!ftrace_pages->next) { + /* allocate another page */ + ftrace_pages->next = + (void *)get_zeroed_page(GFP_KERNEL); + if (!ftrace_pages->next) + return NULL; + } ftrace_pages = ftrace_pages->next; } return &ftrace_pages->records[ftrace_pages->index++]; } -static void +static struct dyn_ftrace * ftrace_record_ip(unsigned long ip) { - struct dyn_ftrace *node; - unsigned long key; - int resched; - int cpu; + struct dyn_ftrace *rec; if (!ftrace_enabled || ftrace_disabled) - return; - - resched = need_resched(); - preempt_disable_notrace(); - - /* - * We simply need to protect against recursion. - * Use the the raw version of smp_processor_id and not - * __get_cpu_var which can call debug hooks that can - * cause a recursive crash here. - */ - cpu = raw_smp_processor_id(); - per_cpu(ftrace_shutdown_disable_cpu, cpu)++; - if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) - goto out; - - if (unlikely(ftrace_record_suspend)) - goto out; - - key = hash_long(ip, FTRACE_HASHBITS); - - FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); - - if (ftrace_ip_in_hash(ip, key)) - goto out; - - /* This ip may have hit the hash before the lock */ - if (ftrace_ip_in_hash(ip, key)) - goto out; - - node = ftrace_alloc_dyn_node(ip); - if (!node) - goto out; + return NULL; - node->ip = ip; + rec = ftrace_alloc_dyn_node(ip); + if (!rec) + return NULL; - ftrace_add_hash(node, key); + rec->ip = ip; - out: - per_cpu(ftrace_shutdown_disable_cpu, cpu)--; + list_add(&rec->list, &ftrace_new_addrs); - /* prevent recursion with scheduler */ - if (resched) - preempt_enable_no_resched_notrace(); - else - preempt_enable_notrace(); + return rec; } #define FTRACE_ADDR ((long)(ftrace_caller)) @@ -543,7 +439,6 @@ static void ftrace_replace_code(int enable) rec->flags |= FTRACE_FL_FAILED; if ((system_state == SYSTEM_BOOTING) || !core_kernel_text(rec->ip)) { - ftrace_del_hash(rec); ftrace_free_rec(rec); } } @@ -551,15 +446,6 @@ static void ftrace_replace_code(int enable) } } -static void ftrace_shutdown_replenish(void) -{ - if (ftrace_pages->next) - return; - - /* allocate another page */ - ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); -} - static void print_ip_ins(const char *fmt, unsigned char *p) { int i; @@ -616,18 +502,11 @@ ftrace_code_disable(struct dyn_ftrace *rec) return 1; } -static int ftrace_update_code(void *ignore); - static int __ftrace_modify_code(void *data) { int *command = data; if (*command & FTRACE_ENABLE_CALLS) { - /* - * Update any recorded ips now that we have the - * machine stopped - */ - ftrace_update_code(NULL); ftrace_replace_code(1); tracing_on = 1; } else if (*command & FTRACE_DISABLE_CALLS) { @@ -738,84 +617,34 @@ static cycle_t ftrace_update_time; static unsigned long ftrace_update_cnt; unsigned long ftrace_update_tot_cnt; -static int ftrace_update_code(void *ignore) +static int ftrace_update_code(void) { - int i, save_ftrace_enabled; + struct dyn_ftrace *p, *t; cycle_t start, stop; - struct dyn_ftrace *p; - struct hlist_node *t, *n; - struct hlist_head *head, temp_list; - - /* Don't be recording funcs now */ - ftrace_record_suspend++; - save_ftrace_enabled = ftrace_enabled; - ftrace_enabled = 0; start = ftrace_now(raw_smp_processor_id()); ftrace_update_cnt = 0; - /* No locks needed, the machine is stopped! */ - for (i = 0; i < FTRACE_HASHSIZE; i++) { - INIT_HLIST_HEAD(&temp_list); - head = &ftrace_hash[i]; + list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { - /* all CPUS are stopped, we are safe to modify code */ - hlist_for_each_entry_safe(p, t, n, head, node) { - /* Skip over failed records which have not been - * freed. */ - if (p->flags & FTRACE_FL_FAILED) - continue; + /* If something went wrong, bail without enabling anything */ + if (unlikely(ftrace_disabled)) + return -1; - /* Unconverted records are always at the head of the - * hash bucket. Once we encounter a converted record, - * simply skip over to the next bucket. Saves ftraced - * some processor cycles (ftrace does its bid for - * global warming :-p ). */ - if (p->flags & (FTRACE_FL_CONVERTED)) - break; + list_del_init(&p->list); - /* Ignore updates to this record's mcount site. - * Reintroduce this record at the head of this - * bucket to attempt to "convert" it again if - * the kprobe on it is unregistered before the - * next run. */ - if (get_kprobe((void *)p->ip)) { - ftrace_del_hash(p); - INIT_HLIST_NODE(&p->node); - hlist_add_head(&p->node, &temp_list); - freeze_record(p); - continue; - } else { - unfreeze_record(p); - } - - /* convert record (i.e, patch mcount-call with NOP) */ - if (ftrace_code_disable(p)) { - p->flags |= FTRACE_FL_CONVERTED; - ftrace_update_cnt++; - } else { - if ((system_state == SYSTEM_BOOTING) || - !core_kernel_text(p->ip)) { - ftrace_del_hash(p); - ftrace_free_rec(p); - } - } - } - - hlist_for_each_entry_safe(p, t, n, &temp_list, node) { - hlist_del(&p->node); - INIT_HLIST_NODE(&p->node); - hlist_add_head(&p->node, head); - } + /* convert record (i.e, patch mcount-call with NOP) */ + if (ftrace_code_disable(p)) { + p->flags |= FTRACE_FL_CONVERTED; + ftrace_update_cnt++; + } else + ftrace_free_rec(p); } stop = ftrace_now(raw_smp_processor_id()); ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; - ftrace_enabled = save_ftrace_enabled; - ftrace_record_suspend--; - return 0; } @@ -847,7 +676,7 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) pg = ftrace_pages = ftrace_pages_start; cnt = num_to_init / ENTRIES_PER_PAGE; - pr_info("ftrace: allocating %ld hash entries in %d pages\n", + pr_info("ftrace: allocating %ld entries in %d pages\n", num_to_init, cnt); for (i = 0; i < cnt; i++) { @@ -1451,20 +1280,18 @@ static int ftrace_convert_nops(unsigned long *start, unsigned long addr; unsigned long flags; + mutex_lock(&ftrace_start_lock); p = start; while (p < end) { addr = ftrace_call_adjust(*p++); - /* should not be called from interrupt context */ - spin_lock(&ftrace_lock); ftrace_record_ip(addr); - spin_unlock(&ftrace_lock); - ftrace_shutdown_replenish(); } - /* p is ignored */ + /* disable interrupts to prevent kstop machine */ local_irq_save(flags); - ftrace_update_code(p); + ftrace_update_code(); local_irq_restore(flags); + mutex_unlock(&ftrace_start_lock); return 0; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 333a516..06951e2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -865,9 +865,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) if (unlikely(!ftrace_function_enabled)) return; - if (skip_trace(ip)) - return; - pc = preempt_count(); resched = need_resched(); preempt_disable_notrace(); -- cgit v1.1 From 3b5d5c6b0ccba733a313f8752ebc3f8015628ba3 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 6 Oct 2008 13:19:27 +0400 Subject: proc: move /proc/modules boilerplate to kernel/module.c Signed-off-by: Alexey Dobriyan --- kernel/module.c | 59 +++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 41 insertions(+), 18 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 0d8d21e..6fded84 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -20,11 +20,13 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include #include @@ -2599,23 +2601,6 @@ unsigned long module_kallsyms_lookup_name(const char *name) } #endif /* CONFIG_KALLSYMS */ -/* Called by the /proc file system to return a list of modules. */ -static void *m_start(struct seq_file *m, loff_t *pos) -{ - mutex_lock(&module_mutex); - return seq_list_start(&modules, *pos); -} - -static void *m_next(struct seq_file *m, void *p, loff_t *pos) -{ - return seq_list_next(p, &modules, pos); -} - -static void m_stop(struct seq_file *m, void *p) -{ - mutex_unlock(&module_mutex); -} - static char *module_flags(struct module *mod, char *buf) { int bx = 0; @@ -2649,6 +2634,24 @@ static char *module_flags(struct module *mod, char *buf) return buf; } +#ifdef CONFIG_PROC_FS +/* Called by the /proc file system to return a list of modules. */ +static void *m_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&module_mutex); + return seq_list_start(&modules, *pos); +} + +static void *m_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &modules, pos); +} + +static void m_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&module_mutex); +} + static int m_show(struct seq_file *m, void *p) { struct module *mod = list_entry(p, struct module, list); @@ -2679,13 +2682,33 @@ static int m_show(struct seq_file *m, void *p) Where refcount is a number or -, and deps is a comma-separated list of depends or -. */ -const struct seq_operations modules_op = { +static const struct seq_operations modules_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = m_show }; +static int modules_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &modules_op); +} + +static const struct file_operations proc_modules_operations = { + .open = modules_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init proc_modules_init(void) +{ + proc_create("modules", 0, NULL, &proc_modules_operations); + return 0; +} +module_init(proc_modules_init); +#endif + /* Given an address, look for it in the module exception tables. */ const struct exception_table_entry *search_module_extables(unsigned long addr) { -- cgit v1.1 From b5aadf7f14c1acc94956aa257e018e9de3881f41 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 6 Oct 2008 13:23:43 +0400 Subject: proc: move /proc/schedstat boilerplate to kernel/sched_stats.h Signed-off-by: Alexey Dobriyan --- kernel/sched.c | 1 + kernel/sched_stats.h | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index d906f72..5a70189 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index b8c1569..3d14ce2 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -90,13 +90,20 @@ static int schedstat_open(struct inode *inode, struct file *file) return res; } -const struct file_operations proc_schedstat_operations = { +static const struct file_operations proc_schedstat_operations = { .open = schedstat_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; +static int __init proc_schedstat_init(void) +{ + proc_create("schedstat", 0, NULL, &proc_schedstat_operations); + return 0; +} +module_init(proc_schedstat_init); + /* * Expects runqueue lock to be held for atomicity of update */ -- cgit v1.1 From 66b0de3569b00f61978782b9f97aa4803dbec0fb Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 23 Oct 2008 16:11:03 +0200 Subject: ftrace: fix build failure fix: kernel/trace/ftrace.c: In function 'ftrace_release': kernel/trace/ftrace.c:271: error: implicit declaration of function 'ftrace_release_hash' release_hash is not needed without dftraced. Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 07762c0..2721232 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -267,8 +267,6 @@ void ftrace_release(void *start, unsigned long size) } } spin_unlock(&ftrace_lock); - - ftrace_release_hash(s, e); } static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) -- cgit v1.1 From d2441183dc222d12961ff2201f5086c846505d93 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 23 Oct 2008 12:07:17 -0700 Subject: Fix compile warning in kernel/params.c Move free_module_param_attrs() into the CONFIG_MODULES section, since it's only used inside there. Thus avoiding the warning kernel/params.c:514: warning: 'free_module_param_attrs' defined but not used Signed-off-by: Linus Torvalds --- kernel/params.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index b077f1b..a1e3025 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -510,6 +510,7 @@ fail: return err; } +#ifdef CONFIG_MODULES static void free_module_param_attrs(struct module_kobject *mk) { kfree(mk->mp->grp.attrs); @@ -517,7 +518,6 @@ static void free_module_param_attrs(struct module_kobject *mk) mk->mp = NULL; } -#ifdef CONFIG_MODULES /* * module_param_sysfs_setup - setup sysfs support for one module * @mod: module -- cgit v1.1 From acff181d3574244e651913df77332e897b88bff4 Mon Sep 17 00:00:00 2001 From: roel kluin Date: Tue, 21 Oct 2008 19:49:09 -0400 Subject: printk: remove unused code from kernel/printk.c both log_buf_copy() and log_buf_len are unused. Signed-off-by: Ingo Molnar --- kernel/printk.c | 39 --------------------------------------- 1 file changed, 39 deletions(-) (limited to 'kernel') diff --git a/kernel/printk.c b/kernel/printk.c index 6341af7..f492f15 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -233,45 +233,6 @@ static inline void boot_delay_msec(void) #endif /* - * Return the number of unread characters in the log buffer. - */ -static int log_buf_get_len(void) -{ - return logged_chars; -} - -/* - * Copy a range of characters from the log buffer. - */ -int log_buf_copy(char *dest, int idx, int len) -{ - int ret, max; - bool took_lock = false; - - if (!oops_in_progress) { - spin_lock_irq(&logbuf_lock); - took_lock = true; - } - - max = log_buf_get_len(); - if (idx < 0 || idx >= max) { - ret = -1; - } else { - if (len > max) - len = max; - ret = len; - idx += (log_end - max); - while (len-- > 0) - dest[len] = LOG_BUF(idx + len); - } - - if (took_lock) - spin_unlock_irq(&logbuf_lock); - - return ret; -} - -/* * Commands to do_syslog: * * 0 -- Close the log. Currently a NOP. -- cgit v1.1 From bea92112415635ecb7e681355834413c7c048f67 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 22 Oct 2008 19:31:11 +0900 Subject: kernel/resource: fix reserve_region_with_split() section mismatch Impact: cleanup, small kernel text size reduction, no functionality changed reserve_region_with_split() calls in to __reserve_region_with_split(), which is an __init function. The only caller of reserve_region_with_split() is an __init function, so make it __init too. Signed-off-by: Paul Mundt Signed-off-by: Ingo Molnar --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/resource.c b/kernel/resource.c index 4089d12..7fec0e4 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -571,7 +571,7 @@ static void __init __reserve_region_with_split(struct resource *root, } -void reserve_region_with_split(struct resource *root, +void __init reserve_region_with_split(struct resource *root, resource_size_t start, resource_size_t end, const char *name) { -- cgit v1.1 From 01c8c57d668d94f1036d9ab11a22aa24ca16a35d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 24 Oct 2008 11:06:12 +0200 Subject: sched: fix a find_busiest_group buglet In one of the group load balancer patches: commit 408ed066b11cf9ee4536573b4269ee3613bd735e Author: Peter Zijlstra Date: Fri Jun 27 13:41:28 2008 +0200 Subject: sched: hierarchical load vs find_busiest_group The following change: - if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >= + if (max_load - this_load + 2*busiest_load_per_task >= busiest_load_per_task * imbn) { made the condition always true, because imbn is [1,2]. Therefore, remove the 2*, and give the it a fair chance. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 6625c3c..12bc367 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3344,7 +3344,7 @@ small_imbalance: } else this_load_per_task = cpu_avg_load_per_task(this_cpu); - if (max_load - this_load + 2*busiest_load_per_task >= + if (max_load - this_load + busiest_load_per_task >= busiest_load_per_task * imbn) { *imbalance = busiest_load_per_task; return busiest; -- cgit v1.1 From 1af5f730fc1bf7c62ec9fb2d307206e18bf40a69 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 24 Oct 2008 11:06:13 +0200 Subject: sched: more accurate min_vruntime accounting Mike noticed the current min_vruntime tracking can go wrong and skip the current task. If the only remaining task in the tree is a nice 19 task with huge vruntime, new tasks will be inserted too far to the right too, causing some interactibity issues. min_vruntime can only change due to the leftmost entry disappearing (dequeue_entity()), or by the leftmost entry being incremented past the next entry, which elects a new leftmost (__update_curr()) Due to the current entry not being part of the actual tree, we have to compare the leftmost tree entry with the current entry, and take the leftmost of these two. So create a update_min_vruntime() function that takes computes the leftmost vruntime in the system (either tree of current) and increases the cfs_rq->min_vruntime if the computed value is larger than the previously found min_vruntime. And call this from the two sites we've identified that can change min_vruntime. Reported-by: Mike Galbraith Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 49 +++++++++++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 42d211f..b27ccc5 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -223,6 +223,27 @@ static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se) return se->vruntime - cfs_rq->min_vruntime; } +static void update_min_vruntime(struct cfs_rq *cfs_rq) +{ + u64 vruntime = cfs_rq->min_vruntime; + + if (cfs_rq->curr) + vruntime = cfs_rq->curr->vruntime; + + if (cfs_rq->rb_leftmost) { + struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost, + struct sched_entity, + run_node); + + if (vruntime == cfs_rq->min_vruntime) + vruntime = se->vruntime; + else + vruntime = min_vruntime(vruntime, se->vruntime); + } + + cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); +} + /* * Enqueue an entity into the rb-tree: */ @@ -256,15 +277,8 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) * Maintain a cache of leftmost tree entries (it is frequently * used): */ - if (leftmost) { + if (leftmost) cfs_rq->rb_leftmost = &se->run_node; - /* - * maintain cfs_rq->min_vruntime to be a monotonic increasing - * value tracking the leftmost vruntime in the tree. - */ - cfs_rq->min_vruntime = - max_vruntime(cfs_rq->min_vruntime, se->vruntime); - } rb_link_node(&se->run_node, parent, link); rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); @@ -274,18 +288,9 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { if (cfs_rq->rb_leftmost == &se->run_node) { struct rb_node *next_node; - struct sched_entity *next; next_node = rb_next(&se->run_node); cfs_rq->rb_leftmost = next_node; - - if (next_node) { - next = rb_entry(next_node, - struct sched_entity, run_node); - cfs_rq->min_vruntime = - max_vruntime(cfs_rq->min_vruntime, - next->vruntime); - } } if (cfs_rq->next == se) @@ -424,6 +429,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, schedstat_add(cfs_rq, exec_clock, delta_exec); delta_exec_weighted = calc_delta_fair(delta_exec, curr); curr->vruntime += delta_exec_weighted; + update_min_vruntime(cfs_rq); } static void update_curr(struct cfs_rq *cfs_rq) @@ -613,13 +619,7 @@ static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) static void place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) { - u64 vruntime; - - if (first_fair(cfs_rq)) { - vruntime = min_vruntime(cfs_rq->min_vruntime, - __pick_next_entity(cfs_rq)->vruntime); - } else - vruntime = cfs_rq->min_vruntime; + u64 vruntime = cfs_rq->min_vruntime; /* * The 'current' period is already promised to the current tasks, @@ -696,6 +696,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) if (se != cfs_rq->curr) __dequeue_entity(cfs_rq, se); account_entity_dequeue(cfs_rq, se); + update_min_vruntime(cfs_rq); } /* -- cgit v1.1 From 0d13033bc9257fe65c1aa25e84568b1608da0901 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 24 Oct 2008 11:06:14 +0200 Subject: sched: weaken sync hint Mysql+oltp and pgsql+oltp peaks are still shifted right. The below puts the peaks back to 1 client/server pair per core. Use the avg_overlap information to weaken the sync hint. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index b27ccc5..b71ee2c 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1123,10 +1123,9 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) return 0; - if (!sync && sched_feat(SYNC_WAKEUPS) && - curr->se.avg_overlap < sysctl_sched_migration_cost && - p->se.avg_overlap < sysctl_sched_migration_cost) - sync = 1; + if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || + p->se.avg_overlap > sysctl_sched_migration_cost)) + sync = 0; /* * If sync wakeup then subtract the (maximum possible) -- cgit v1.1 From 464b75273f64be7c81fee975bd6ca9593df3427b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 24 Oct 2008 11:06:15 +0200 Subject: sched: re-instate vruntime based wakeup preemption The advantage is that vruntime based wakeup preemption has a better conceptual model. Here wakeup_gran = 0 means: preempt when 'fair'. Therefore wakeup_gran is the granularity of unfairness we allow in order to make progress. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 92 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index b71ee2c..7af17e0 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -143,6 +143,49 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se) return se->parent; } +/* return depth at which a sched entity is present in the hierarchy */ +static inline int depth_se(struct sched_entity *se) +{ + int depth = 0; + + for_each_sched_entity(se) + depth++; + + return depth; +} + +static void +find_matching_se(struct sched_entity **se, struct sched_entity **pse) +{ + int se_depth, pse_depth; + + /* + * preemption test can be made between sibling entities who are in the + * same cfs_rq i.e who have a common parent. Walk up the hierarchy of + * both tasks until we find their ancestors who are siblings of common + * parent. + */ + + /* First walk up until both entities are at same depth */ + se_depth = depth_se(*se); + pse_depth = depth_se(*pse); + + while (se_depth > pse_depth) { + se_depth--; + *se = parent_entity(*se); + } + + while (pse_depth > se_depth) { + pse_depth--; + *pse = parent_entity(*pse); + } + + while (!is_same_group(*se, *pse)) { + *se = parent_entity(*se); + *pse = parent_entity(*pse); + } +} + #else /* CONFIG_FAIR_GROUP_SCHED */ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) @@ -193,6 +236,11 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se) return NULL; } +static inline void +find_matching_se(struct sched_entity **se, struct sched_entity **pse) +{ +} + #endif /* CONFIG_FAIR_GROUP_SCHED */ @@ -1244,13 +1292,42 @@ static unsigned long wakeup_gran(struct sched_entity *se) * More easily preempt - nice tasks, while not making it harder for * + nice tasks. */ - if (sched_feat(ASYM_GRAN)) - gran = calc_delta_mine(gran, NICE_0_LOAD, &se->load); + if (!sched_feat(ASYM_GRAN) || se->load.weight > NICE_0_LOAD) + gran = calc_delta_fair(sysctl_sched_wakeup_granularity, se); return gran; } /* + * Should 'se' preempt 'curr'. + * + * |s1 + * |s2 + * |s3 + * g + * |<--->|c + * + * w(c, s1) = -1 + * w(c, s2) = 0 + * w(c, s3) = 1 + * + */ +static int +wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) +{ + s64 gran, vdiff = curr->vruntime - se->vruntime; + + if (vdiff <= 0) + return -1; + + gran = wakeup_gran(curr); + if (vdiff > gran) + return 1; + + return 0; +} + +/* * Preempt the current task with a newly woken task if needed: */ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) @@ -1258,7 +1335,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); struct sched_entity *se = &curr->se, *pse = &p->se; - s64 delta_exec; if (unlikely(rt_prio(p->prio))) { update_rq_clock(rq); @@ -1296,9 +1372,19 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) return; } - delta_exec = se->sum_exec_runtime - se->prev_sum_exec_runtime; - if (delta_exec > wakeup_gran(pse)) - resched_task(curr); + find_matching_se(&se, &pse); + + while (se) { + BUG_ON(!pse); + + if (wakeup_preempt_entity(se, pse) == 1) { + resched_task(curr); + break; + } + + se = parent_entity(se); + pse = parent_entity(pse); + } } static struct task_struct *pick_next_task_fair(struct rq *rq) -- cgit v1.1 From 3f3a490480d8ab96e0fe30a41f80f14e6a0c579d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 24 Oct 2008 11:06:16 +0200 Subject: sched: virtual time buddy preemption Since we moved wakeup preemption back to virtual time, it makes sense to move the buddy stuff back as well. The purpose of the buddy scheduling is to allow a quickly scheduling pair of tasks to run away from the group as far as a regular busy task would be allowed under wakeup preemption. This has the advantage that the pair can ping-pong for a while, enjoying cache-hotness. Without buddy scheduling other tasks would interleave destroying the cache. Also, it saves a word in cfs_rq. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched.c | 1 - kernel/sched_fair.c | 10 ++++------ 2 files changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 12bc367..e8819bc 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -386,7 +386,6 @@ struct cfs_rq { u64 exec_clock; u64 min_vruntime; - u64 pair_start; struct rb_root tasks_timeline; struct rb_node *rb_leftmost; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 7af17e0..ce514af 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -791,16 +791,14 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) se->prev_sum_exec_runtime = se->sum_exec_runtime; } +static int +wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); + static struct sched_entity * pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) { - struct rq *rq = rq_of(cfs_rq); - u64 pair_slice = rq->clock - cfs_rq->pair_start; - - if (!cfs_rq->next || pair_slice > sysctl_sched_min_granularity) { - cfs_rq->pair_start = rq->clock; + if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1) return se; - } return cfs_rq->next; } -- cgit v1.1 From f17845e5d97ead8fbdadfd40039e058ec7cf4a42 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 24 Oct 2008 12:47:10 +0200 Subject: ftrace: warning in kernel/trace/ftrace.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit this warning: kernel/trace/ftrace.c:189: warning: ‘frozen_record_count’ defined but not used triggers because frozen_record_count is only used in the KCONFIG_MARKERS case. Move the variable it there. Alas, this frozen-record facility seems to have little use. The frozen_record_count variable is not used by anything, nor the flags. So this section might need a bit of dead-code-removal care as well. Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2721232..7618c52 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -186,7 +186,6 @@ enum { static int ftrace_filtered; static int tracing_on; -static int frozen_record_count; static LIST_HEAD(ftrace_new_addrs); @@ -211,6 +210,9 @@ static struct dyn_ftrace *ftrace_free_records; #ifdef CONFIG_KPROBES + +static int frozen_record_count; + static inline void freeze_record(struct dyn_ftrace *rec) { if (!(rec->flags & FTRACE_FL_FROZEN)) { @@ -1443,3 +1445,4 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_unlock(&ftrace_sysctl_lock); return ret; } + -- cgit v1.1 From 4403b406d4369a275d483ece6ddee0088cc0d592 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 25 Oct 2008 19:53:38 -0700 Subject: Revert "Call init_workqueues before pre smp initcalls." This reverts commit a802dd0eb5fc97a50cf1abb1f788a8f6cc5db635 by moving the call to init_workqueues() back where it belongs - after SMP has been initialized. It also moves stop_machine_init() - which needs workqueues - to a later phase using a core_initcall() instead of early_initcall(). That should satisfy all ordering requirements, and was apparently the reason why init_workqueues() was moved to be too early. Cc: Heiko Carstens Cc: Rusty Russell Signed-off-by: Linus Torvalds --- kernel/stop_machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 8aff79d..9bc4c00 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -160,4 +160,4 @@ static int __init stop_machine_init(void) stop_machine_work = alloc_percpu(struct work_struct); return 0; } -early_initcall(stop_machine_init); +core_initcall(stop_machine_init); -- cgit v1.1 From 2077776641b6ffb0049f13018d2e162340ec51c7 Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Tue, 21 Oct 2008 16:11:20 +1100 Subject: cgroup: remove unused variable /scratch/sfr/next/kernel/cgroup.c: In function 'cgroup_tasks_start': /scratch/sfr/next/kernel/cgroup.c:2107: warning: unused variable 'i' Introduced in commit cc31edceee04a7b87f2be48f9489ebb72d264844 "cgroups: convert tasks file to use a seq_file with shared pid array". Signed-off-by: Stephen Rothwell Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 046c160..35eebd5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2104,7 +2104,7 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) down_read(&cgrp->pids_mutex); if (pid) { int end = cgrp->pids_length; - int i; + while (index < end) { int mid = (index + end) / 2; if (cgrp->tasks_pids[mid] == pid) { -- cgit v1.1 From e2862c9470beb842d3f1c1965b03a2112114c160 Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Mon, 27 Oct 2008 17:43:28 +1100 Subject: trace: fix printk warning for u64 A powerpc ppc64_defconfig build produces these warnings: kernel/trace/ring_buffer.c: In function 'rb_add_time_stamp': kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 2 has type 'u64' kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'u64' kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type 'u64' Just cast the u64s to unsigned long long like we do everywhere else. Signed-off-by: Stephen Rothwell Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 091aeef..cedf4e2 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -966,7 +966,9 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, if (unlikely(*delta > (1ULL << 59) && !once++)) { printk(KERN_WARNING "Delta way too big! %llu" " ts=%llu write stamp = %llu\n", - *delta, *ts, cpu_buffer->write_stamp); + (unsigned long long)*delta, + (unsigned long long)*ts, + (unsigned long long)cpu_buffer->write_stamp); WARN_ON(1); } -- cgit v1.1 From f66af459a931f25807e1df7915b2b66bb5978d82 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Oct 2008 19:14:55 +0200 Subject: tracepoint: check if the probe has been registered Impact: fix kernel crash that can trigger during tracing If we try to remove a probe that has not been already registered, the tracepoint_entry_remove_probe() function will dereference a NULL pointer. Check the probe before removing it to avoid crashes. Signed-off-by: Frederic Weisbecker Acked-by: Mathieu Desnoyers Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index f2b7c28..af8c856 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -131,6 +131,9 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe) old = entry->funcs; + if (!old) + return NULL; + debug_print_probes(entry); /* (N -> M), (N > 1, M >= 0) probes */ for (nr_probes = 0; old[nr_probes]; nr_probes++) { @@ -388,6 +391,11 @@ int tracepoint_probe_unregister(const char *name, void *probe) if (entry->rcu_pending) rcu_barrier_sched(); old = tracepoint_entry_remove_probe(entry, probe); + if (!old) { + printk(KERN_WARNING "Warning: Trying to unregister a probe" + "that doesn't exist\n"); + goto end; + } mutex_unlock(&tracepoints_mutex); tracepoint_update_probes(); /* may update entry */ mutex_lock(&tracepoints_mutex); -- cgit v1.1 From ea31e72d753e5817a97de552f152d0cb55c7defc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Oct 2008 19:26:23 +0200 Subject: tracing/ftrace: make boot tracer select the sched_switch tracer Impact: build fix If the boot tracer is selected but not the sched_switch, there will be a build failure: kernel/built-in.o: In function `boot_trace_init': trace_boot.c:(.text+0x5ee38): undefined reference to `sched_switch_trace' kernel/built-in.o: In function `disable_boot_trace': (.text+0x5eee1): undefined reference to `tracing_stop_cmdline_record' kernel/built-in.o: In function `enable_boot_trace': (.text+0x5ef11): undefined reference to `tracing_start_cmdline_record' This patch fixes it. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index bc535cb..e0cea28 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -123,6 +123,7 @@ config BOOT_TRACER bool "Trace boot initcalls" depends on DEBUG_KERNEL select TRACING + select CONTEXT_SWITCH_TRACER help This tracer helps developers to optimize boot times: it records the timings of the initcalls and traces key events and the identity -- cgit v1.1 From 21798a84ab383cdac0e7ee3368e0792b718b867d Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 28 Oct 2008 09:43:26 +0100 Subject: tracing: fix a build error on alpha Impact: build fix on Alpha When tracing is enabled, some arch have included on their but others like alpha or m68k don't. Build error on alpha: kernel/trace/trace.c: In function 'tracing_cpumask_write': kernel/trace/trace.c:2145: error: implicit declaration of function 'raw_local_irq_disable' kernel/trace/trace.c:2162: error: implicit declaration of function 'raw_local_irq_enable' Tested on Alpha through a cross-compiler (should correct a similar issue on m68k). Reported-by: Alexey Dobriyan Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 06951e2..bc577dc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -34,6 +34,7 @@ #include #include +#include #include "trace.h" -- cgit v1.1 From 46fec7ac40e452a2ea5e63648d98b6bb2b5898f9 Mon Sep 17 00:00:00 2001 From: qinghuang feng Date: Tue, 28 Oct 2008 17:24:28 +0800 Subject: lockdep: minor fix for debug_show_all_locks() When we failed to get tasklist_lock eventually (count equals 0), we should only print " ignoring it.\n", and not print " locked it.\n" needlessly. Signed-off-by: Qinghuang Feng Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index dbda475..11832ac 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3417,9 +3417,10 @@ retry: } printk(" ignoring it.\n"); unlock = 0; + } else { + if (count != 10) + printk(KERN_CONT " locked it.\n"); } - if (count != 10) - printk(" locked it.\n"); do_each_thread(g, p) { /* -- cgit v1.1 From 6afe40b4dace385d7ba2faf24b352f066f3b71bf Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 28 Oct 2008 11:14:58 +0100 Subject: lockdep: fix irqs on/off ip tracing Impact: fix lockdep lock-api-caller output when irqsoff tracing is enabled 81d68a96 "ftrace: trace irq disabled critical timings" added wrappers around trace_hardirqs_on/off_caller. However these functions use __builtin_return_address(0) to figure out which function actually disabled or enabled irqs. The result is that we save the ips of trace_hardirqs_on/off instead of the real caller. Not very helpful. However since the patch from Steven the ip already gets passed. So use that and get rid of __builtin_return_address(0) in these two functions. Signed-off-by: Heiko Carstens Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 11832ac..06e1571 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2169,12 +2169,11 @@ void early_boot_irqs_on(void) /* * Hardirqs will be enabled: */ -void trace_hardirqs_on_caller(unsigned long a0) +void trace_hardirqs_on_caller(unsigned long ip) { struct task_struct *curr = current; - unsigned long ip; - time_hardirqs_on(CALLER_ADDR0, a0); + time_hardirqs_on(CALLER_ADDR0, ip); if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2188,7 +2187,6 @@ void trace_hardirqs_on_caller(unsigned long a0) } /* we'll do an OFF -> ON transition: */ curr->hardirqs_enabled = 1; - ip = (unsigned long) __builtin_return_address(0); if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return; @@ -2224,11 +2222,11 @@ EXPORT_SYMBOL(trace_hardirqs_on); /* * Hardirqs were disabled: */ -void trace_hardirqs_off_caller(unsigned long a0) +void trace_hardirqs_off_caller(unsigned long ip) { struct task_struct *curr = current; - time_hardirqs_off(CALLER_ADDR0, a0); + time_hardirqs_off(CALLER_ADDR0, ip); if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2241,7 +2239,7 @@ void trace_hardirqs_off_caller(unsigned long a0) * We have done an ON -> OFF transition: */ curr->hardirqs_enabled = 0; - curr->hardirq_disable_ip = _RET_IP_; + curr->hardirq_disable_ip = ip; curr->hardirq_disable_event = ++curr->irq_events; debug_atomic_inc(&hardirqs_off_events); } else -- cgit v1.1 From 60063a66236c15f5613f91390631e06718689782 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 28 Oct 2008 10:44:24 -0400 Subject: ftrace: fix current_tracer error return The commit (in linux-tip) c2931e05ec5965597cbfb79ad332d4a29aeceb23 ( ftrace: return an error when setting a nonexistent tracer ) added useful code that would error when a bad tracer was written into the current_tracer file. But this had a bug if the amount written was more than the amount read by that code. The first iteration would set the tracer correctly, but since it did not consume the rest of what was written (usually whitespace), the userspace utility would continue to write what was not consumed. This second iteration would fail to find a tracer and return -EINVAL. Funny thing is that the tracer would have already been set. This patch just consumes all the data that is written to the file. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bc577dc..a610ca7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2377,9 +2377,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, int i; size_t ret; + ret = cnt; + if (cnt > max_tracer_type_len) cnt = max_tracer_type_len; - ret = cnt; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; @@ -2412,8 +2413,8 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&trace_types_lock); - if (ret == cnt) - filp->f_pos += cnt; + if (ret > 0) + filp->f_pos += ret; return ret; } -- cgit v1.1 From 0b6e4d56bf71866a2b58daa8323cf747988ce7e4 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 28 Oct 2008 20:17:38 +0100 Subject: ftrace: perform an initialization for ftrace to enable it Impact: corrects a bug which made the non-dyn function tracer not functional With latest git, the non-dynamic function tracer didn't get any trace. The problem was the fact that ftrace_enabled wasn't initialized to 1 because ftrace hasn't any init function when DYNAMIC_FTRACE is disabled. So when a tracer tries to register an ftrace_ops struct, __register_ftrace_function failed to set the hook. This patch corrects it by setting an init function to initialize ftrace during the boot. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7618c52..4a39d24 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1339,6 +1339,14 @@ void __init ftrace_init(void) } #else + +static int __init ftrace_nodyn_init(void) +{ + ftrace_enabled = 1; + return 0; +} +device_initcall(ftrace_nodyn_init); + # define ftrace_startup() do { } while (0) # define ftrace_shutdown() do { } while (0) # define ftrace_startup_sysctl() do { } while (0) -- cgit v1.1 From d68612b257b5f4ea2e6535859c5a26b10011a9df Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 28 Oct 2008 11:45:42 -0700 Subject: resources: fix x86info results ioremap.c:226 __ioremap_caller+0xf2/0x2d6() WARNINGs Impact: avoid false-positive WARN_ON() Andi Kleen reported: > When running x86info on a 2.6.27-git8 system I get > > resource map sanity check conflict: 0x9e000 0x9efff 0x10000 0x9e7ff System RAM > ------------[ cut here ]------------ > WARNING: at /home/lsrc/linux/arch/x86/mm/ioremap.c:226 __ioremap_caller+0xf2/0x2d6() > ... Some of the pages below the 1MB ISA addresses will be shared typically by both BIOS and system usable RAM. For example: BIOS-e820: 0000000000000000 - 000000000009f800 (usable) BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved) x86info reads the low physical address using /dev/mem, which internally uses ioremap() for accessing non RAM pages. ioremap() of such low pages conflicts with multiple resource entities leading to the above warning. Change the iomem_map_sanity_check() to allow mapping a page spanning multiple resource entities (minimum granularity that one can map is a page anyhow). Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- kernel/resource.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/resource.c b/kernel/resource.c index 7fec0e4..6aac5c6 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -17,6 +17,7 @@ #include #include #include +#include #include @@ -849,7 +850,8 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) continue; if (p->end < addr) continue; - if (p->start <= addr && (p->end >= addr + size - 1)) + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && + PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) continue; printk(KERN_WARNING "resource map sanity check conflict: " "0x%llx 0x%llx 0x%llx 0x%llx %s\n", -- cgit v1.1 From f3384b28a05624783b53836ccfed95ecde66a7ad Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 29 Oct 2008 11:15:57 -0400 Subject: ftrace: fix trace_nop config select Impact: build fix on non-function-tracing architectures The trace_nop is the tracer that is defined when no tracer is set in the ftrace infrastructure. The trace_nop was mistakenly selected by HAVE_FTRACE due to the confusion between ftrace infrastructure and the ftrace function tracer (which has been solved by renaming the function tracer). This patch changes the select to the approriate TRACING. This patch should fix compile errors on architectures that do not define the FUNCTION_TRACER. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e0cea28..b58f43b 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -8,7 +8,6 @@ config NOP_TRACER config HAVE_FUNCTION_TRACER bool - select NOP_TRACER config HAVE_DYNAMIC_FTRACE bool @@ -28,6 +27,7 @@ config TRACING select RING_BUFFER select STACKTRACE select TRACEPOINTS + select NOP_TRACER menu "Tracers" -- cgit v1.1 From a9cf4ddb3b2ce03c3027929b22a920aeff933009 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 30 Oct 2008 15:23:34 +0800 Subject: sched: change sched_debug's mode to 0444 Impact: change /proc/sched/debug from rw-r--r-- to r--r--r-- /proc/sched_debug is read-only. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index ad958c1..5ae1776 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -319,7 +319,7 @@ static int __init init_sched_debug_procfs(void) { struct proc_dir_entry *pe; - pe = proc_create("sched_debug", 0644, NULL, &sched_debug_fops); + pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops); if (!pe) return -ENOMEM; return 0; -- cgit v1.1 From 7ccb97437bcc818d0ba6067513475f6ee8177a15 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 29 Oct 2008 14:00:51 -0700 Subject: freezer_cg: fix improper BUG_ON() causing oops The BUG_ON() should be protected by freezer->lock, otherwise it can be triggered easily when a task has been unfreezed but the corresponding cgroup hasn't been changed to FROZEN state. Signed-off-by: Li Zefan Acked-by: Cedric Le Goater Acked-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index e950569..7f54d1c 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -190,8 +190,9 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) freezer = task_freezer(task); task_unlock(task); - BUG_ON(freezer->state == CGROUP_FROZEN); spin_lock_irq(&freezer->lock); + BUG_ON(freezer->state == CGROUP_FROZEN); + /* Locking avoids race with FREEZING -> THAWED transitions. */ if (freezer->state == CGROUP_FREEZING) freeze_task(task, true); -- cgit v1.1 From 80a6a2cf3bebcf20285cf05373b9c5ec96816577 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 29 Oct 2008 14:00:52 -0700 Subject: freezer_cg: remove redundant check in freezer_can_attach() It is sufficient to check if @task is frozen, and no need to check if the original freezer is frozen. Signed-off-by: Li Zefan Acked-by: Cedric Le Goater Acked-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 7f54d1c..e9c856a 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -162,9 +162,13 @@ static int freezer_can_attach(struct cgroup_subsys *ss, struct task_struct *task) { struct freezer *freezer; - int retval; - /* Anything frozen can't move or be moved to/from */ + /* + * Anything frozen can't move or be moved to/from. + * + * Since orig_freezer->state == FROZEN means that @task has been + * frozen, so it's sufficient to check the latter condition. + */ if (is_task_frozen_enough(task)) return -EBUSY; @@ -173,13 +177,7 @@ static int freezer_can_attach(struct cgroup_subsys *ss, if (freezer->state == CGROUP_FROZEN) return -EBUSY; - retval = 0; - task_lock(task); - freezer = task_freezer(task); - if (freezer->state == CGROUP_FROZEN) - retval = -EBUSY; - task_unlock(task); - return retval; + return 0; } static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) -- cgit v1.1 From 00c2e63c31d0f431952ff2a671c5c6997dd4f8b2 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 29 Oct 2008 14:00:53 -0700 Subject: freezer_cg: use thaw_process() in unfreeze_cgroup() Don't duplicate the implementation of thaw_process(). [akpm@linux-foundation.org: make __thaw_process() static] Signed-off-by: Li Zefan Cc: Cedric Le Goater Acked-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 15 ++++----------- kernel/freezer.c | 20 ++++++++++---------- 2 files changed, 14 insertions(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index e9c856a..5e6d26b 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -275,25 +275,18 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) return num_cant_freeze_now ? -EBUSY : 0; } -static int unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) +static void unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) { struct cgroup_iter it; struct task_struct *task; cgroup_iter_start(cgroup, &it); while ((task = cgroup_iter_next(cgroup, &it))) { - int do_wake; - - task_lock(task); - do_wake = __thaw_process(task); - task_unlock(task); - if (do_wake) - wake_up_process(task); + thaw_process(task); } cgroup_iter_end(cgroup, &it); - freezer->state = CGROUP_THAWED; - return 0; + freezer->state = CGROUP_THAWED; } static int freezer_change_state(struct cgroup *cgroup, @@ -320,7 +313,7 @@ static int freezer_change_state(struct cgroup *cgroup, } /* state == FREEZING and goal_state == THAWED, so unfreeze */ case CGROUP_FROZEN: - retval = unfreeze_cgroup(cgroup, freezer); + unfreeze_cgroup(cgroup, freezer); break; default: break; diff --git a/kernel/freezer.c b/kernel/freezer.c index ba6248b..2f4936c 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -121,16 +121,7 @@ void cancel_freezing(struct task_struct *p) } } -/* - * Wake up a frozen process - * - * task_lock() is needed to prevent the race with refrigerator() which may - * occur if the freezing of tasks fails. Namely, without the lock, if the - * freezing of tasks failed, thaw_tasks() might have run before a task in - * refrigerator() could call frozen_process(), in which case the task would be - * frozen and no one would thaw it. - */ -int __thaw_process(struct task_struct *p) +static int __thaw_process(struct task_struct *p) { if (frozen(p)) { p->flags &= ~PF_FROZEN; @@ -140,6 +131,15 @@ int __thaw_process(struct task_struct *p) return 0; } +/* + * Wake up a frozen process + * + * task_lock() is needed to prevent the race with refrigerator() which may + * occur if the freezing of tasks fails. Namely, without the lock, if the + * freezing of tasks failed, thaw_tasks() might have run before a task in + * refrigerator() could call frozen_process(), in which case the task would be + * frozen and no one would thaw it. + */ int thaw_process(struct task_struct *p) { task_lock(p); -- cgit v1.1 From 51308ee59dee1136ed599d875ea8968d7be55c91 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 29 Oct 2008 14:00:54 -0700 Subject: freezer_cg: simplify freezer_change_state() Just call unfreeze_cgroup() if goal_state == THAWED, and call try_to_freeze_cgroup() if goal_state == FROZEN. No behavior has been changed. Signed-off-by: Li Zefan Acked-by: Cedric Le Goater Acked-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup_freezer.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 5e6d26b..7fa476f 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -296,27 +296,22 @@ static int freezer_change_state(struct cgroup *cgroup, int retval = 0; freezer = cgroup_freezer(cgroup); + spin_lock_irq(&freezer->lock); + update_freezer_state(cgroup, freezer); if (goal_state == freezer->state) goto out; - switch (freezer->state) { + + switch (goal_state) { case CGROUP_THAWED: - retval = try_to_freeze_cgroup(cgroup, freezer); + unfreeze_cgroup(cgroup, freezer); break; - case CGROUP_FREEZING: - if (goal_state == CGROUP_FROZEN) { - /* Userspace is retrying after - * "/bin/echo FROZEN > freezer.state" returned -EBUSY */ - retval = try_to_freeze_cgroup(cgroup, freezer); - break; - } - /* state == FREEZING and goal_state == THAWED, so unfreeze */ case CGROUP_FROZEN: - unfreeze_cgroup(cgroup, freezer); + retval = try_to_freeze_cgroup(cgroup, freezer); break; default: - break; + BUG(); } out: spin_unlock_irq(&freezer->lock); -- cgit v1.1 From ce05fcc30ea41c85f9d50bee1ce289f7cb7fb223 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 29 Oct 2008 14:01:07 -0700 Subject: kernel/profile: fix profile_init() section mismatch profile_init() calls in to alloc_bootmem() on early initialization. While alloc_bootmem() is __init, the reference itself is safe in that it is tucked below a !slab_is_available() check. So, flag profile_init() as __ref. Signed-off-by: Paul Mundt Cc: Dave Hansen Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/profile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/profile.c b/kernel/profile.c index a9e422d..9830a03 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -102,7 +102,7 @@ int profile_setup(char *str) __setup("profile=", profile_setup); -int profile_init(void) +int __ref profile_init(void) { int buffer_bytes; if (!prof_on) -- cgit v1.1 From d25141a818383b3c3b09f065698c544a7a0ec6e7 Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Wed, 29 Oct 2008 14:01:11 -0700 Subject: 'kill sig -1' must only apply to caller's namespace Currently "kill -1" kills processes in all namespaces and breaks the isolation of namespaces. Earlier attempt to fix this was discussed at: http://lkml.org/lkml/2008/7/23/148 As suggested by Oleg Nesterov in that thread, use "task_pid_vnr() > 1" check since task_pid_vnr() returns 0 if process is outside the caller's namespace. Signed-off-by: Sukadev Bhattiprolu Acked-by: Eric W. Biederman Tested-by: Daniel Hokka Zakrisson Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index 105217d..4530fc6 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1144,7 +1144,8 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid) struct task_struct * p; for_each_process(p) { - if (p->pid > 1 && !same_thread_group(p, current)) { + if (task_pid_vnr(p) > 1 && + !same_thread_group(p, current)) { int err = group_send_sig_info(sig, info, p); ++count; if (err != -EPERM) -- cgit v1.1 From 9244489a7b69fe0746dc7cb3957f02e05bd1ceb0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 24 Oct 2008 09:42:59 -0400 Subject: ftrace: handle archs that do not support irqs_disabled_flags Impact: build fix on non-lockdep architectures Some architectures do not support a way to read the irq flags that is set from "local_irq_save(flags)" to determine if interrupts were disabled or enabled. Ftrace uses this information to display to the user if the trace occurred with interrupts enabled or disabled. Besides the fact that those archs that do not support this will fail to compile, unless they fix it, we do not want to have the trace simply say interrupts were not disabled or they were enabled, without knowing the real answer. This patch adds a 'X' in the output to let the user know that the architecture they are running on does not support a way for the tracer to determine if interrupts were enabled or disabled. It also lets those same archs compile with tracing enabled. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 7 ++++++- kernel/trace/trace.h | 20 +++++++++++--------- 2 files changed, 17 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a610ca7..8a499e2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -656,7 +656,11 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; entry->flags = +#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | +#else + TRACE_FLAG_IRQS_NOSUPPORT | +#endif ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); @@ -1244,7 +1248,8 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); trace_seq_printf(s, "%3d", cpu); trace_seq_printf(s, "%c%c", - (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', + (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : + (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.', ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6889ca4..8465ad0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -120,18 +120,20 @@ struct trace_boot { /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: - * IRQS_OFF - interrupts were disabled - * NEED_RESCED - reschedule is requested - * HARDIRQ - inside an interrupt handler - * SOFTIRQ - inside a softirq handler - * CONT - multiple entries hold the trace item + * IRQS_OFF - interrupts were disabled + * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags + * NEED_RESCED - reschedule is requested + * HARDIRQ - inside an interrupt handler + * SOFTIRQ - inside a softirq handler + * CONT - multiple entries hold the trace item */ enum trace_flag_type { TRACE_FLAG_IRQS_OFF = 0x01, - TRACE_FLAG_NEED_RESCHED = 0x02, - TRACE_FLAG_HARDIRQ = 0x04, - TRACE_FLAG_SOFTIRQ = 0x08, - TRACE_FLAG_CONT = 0x10, + TRACE_FLAG_IRQS_NOSUPPORT = 0x02, + TRACE_FLAG_NEED_RESCHED = 0x04, + TRACE_FLAG_HARDIRQ = 0x08, + TRACE_FLAG_SOFTIRQ = 0x10, + TRACE_FLAG_CONT = 0x20, }; #define TRACE_BUF_SIZE 1024 -- cgit v1.1 From 42c0202363194007a1ac377d047a95aa39246eb0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 1 Nov 2008 09:53:58 -0700 Subject: reserve_region_with_split: Fix GFP_KERNEL usage under spinlock This one apparently doesn't generate any warnings, because the function is only used during system bootup, when the warnings are disabled. But it's still very wrong. The __reserve_region_with_split() function is called with the resource_lock held for writing, so it must only ever do GFP_ATOMIC allocations. Signed-off-by: Linus Torvalds --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/resource.c b/kernel/resource.c index 6aac5c6..4337063 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -523,7 +523,7 @@ static void __init __reserve_region_with_split(struct resource *root, { struct resource *parent = root; struct resource *conflict; - struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); if (!res) return; -- cgit v1.1 From 28959742c14918f153c1de641bb12b4ea44315a1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 1 Nov 2008 18:20:09 +0000 Subject: PM_TEST_SUSPEND should depend on RTC_CLASS, not RTC_LIB Insufficient dependency - we really want CONFIG_RTC_CLASS=y there. That will give us CONFIG_RTC_LIB=y, so the old dependency can be simply replaced. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds --- kernel/power/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index dcd165f..23bd4da 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -96,7 +96,7 @@ config SUSPEND config PM_TEST_SUSPEND bool "Test suspend/resume and wakealarm during bootup" - depends on SUSPEND && PM_DEBUG && RTC_LIB=y + depends on SUSPEND && PM_DEBUG && RTC_CLASS=y ---help--- This option will let you suspend your machine during bootup, and make it wake up a few seconds later using an RTC wakeup alarm. -- cgit v1.1 From c2c80529460095035752bf0ecc1af82c1e0f6e0f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 31 Oct 2008 19:50:41 +0000 Subject: tracing, alpha: undefined reference to `save_stack_trace' Impact: build fix on !stacktrace architectures only select STACKTRACE on architectures that have STACKTRACE_SUPPORT ... since we also need to ifdef out the guts of ftrace_trace_stack(). We also want to disallow setting TRACE_ITER_STACKTRACE in trace_flags on such configs, but that can wait. Signed-off-by: Al Viro Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 2 +- kernel/trace/trace.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index b58f43b..33dbefd 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -25,7 +25,7 @@ config TRACING bool select DEBUG_FS select RING_BUFFER - select STACKTRACE + select STACKTRACE if STACKTRACE_SUPPORT select TRACEPOINTS select NOP_TRACER diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8a499e2..85bee77 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -705,6 +705,7 @@ static void ftrace_trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc) { +#ifdef CONFIG_STACKTRACE struct ring_buffer_event *event; struct stack_entry *entry; struct stack_trace trace; @@ -730,6 +731,7 @@ static void ftrace_trace_stack(struct trace_array *tr, save_stack_trace(&trace); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); +#endif } void __trace_stack(struct trace_array *tr, -- cgit v1.1 From b3aa557722b3d5858f14ca559e03461c24125aaf Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 31 Oct 2008 15:44:07 -0400 Subject: ftrace: use kretprobe trampoline name to test in output Impact: ia64+tracing build fix When a function is kprobed, the return address is set to the kprobe_trampoline, or something similar. This caused the output of the trace to look confusing when the parent seemed to be this "kprobe_trampoline" function. To fix this, Abhishek Sagar added a test of the instruction pointer of the parent to see if it matched the kprobe_trampoline. If it did, the output would print a "[unknown/kretprobe'd]" instead. Unfortunately, not all archs do this the same way, and the trampoline function may not be exported, which causes failures in builds. This patch will compare the name instead of the pointer to see if it matches. This prevents us from depending on a function from being exported, and should work on all archs. The worst that can happen is that an arch might use a different name and then we go back to the confusing output. At least the arch will still build. Reported-by: Abhishek Sagar Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Tested-by: Abhishek Sagar Acked-by: Abhishek Sagar --- kernel/trace/trace.c | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 85bee77..9f3b478 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1088,17 +1088,20 @@ static void s_stop(struct seq_file *m, void *p) mutex_unlock(&trace_types_lock); } -#define KRETPROBE_MSG "[unknown/kretprobe'd]" - #ifdef CONFIG_KRETPROBES -static inline int kretprobed(unsigned long addr) +static inline const char *kretprobed(const char *name) { - return addr == (unsigned long)kretprobe_trampoline; + static const char tramp_name[] = "kretprobe_trampoline"; + int size = sizeof(tramp_name); + + if (strncmp(tramp_name, name, size) == 0) + return "[unknown/kretprobe'd]"; + return name; } #else -static inline int kretprobed(unsigned long addr) +static inline const char *kretprobed(const char *name) { - return 0; + return name; } #endif /* CONFIG_KRETPROBES */ @@ -1107,10 +1110,13 @@ seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) { #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; + const char *name; kallsyms_lookup(address, NULL, NULL, NULL, str); - return trace_seq_printf(s, fmt, str); + name = kretprobed(str); + + return trace_seq_printf(s, fmt, name); #endif return 1; } @@ -1121,9 +1127,12 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt, { #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; + const char *name; sprint_symbol(str, address); - return trace_seq_printf(s, fmt, str); + name = kretprobed(str); + + return trace_seq_printf(s, fmt, name); #endif return 1; } @@ -1377,10 +1386,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_puts(s, " ("); - if (kretprobed(field->parent_ip)) - trace_seq_puts(s, KRETPROBE_MSG); - else - seq_print_ip_sym(s, field->parent_ip, sym_flags); + seq_print_ip_sym(s, field->parent_ip, sym_flags); trace_seq_puts(s, ")\n"); break; } @@ -1496,12 +1502,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) ret = trace_seq_printf(s, " <-"); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - if (kretprobed(field->parent_ip)) - ret = trace_seq_puts(s, KRETPROBE_MSG); - else - ret = seq_print_ip_sym(s, - field->parent_ip, - sym_flags); + ret = seq_print_ip_sym(s, + field->parent_ip, + sym_flags); if (!ret) return TRACE_TYPE_PARTIAL_LINE; } -- cgit v1.1 From 818e3dd30a4ff34fff6d90e87ae59c73f6a53691 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 31 Oct 2008 09:58:35 -0400 Subject: tracing, ring-buffer: add paranoid checks for loops While writing a new tracer, I had a bug where I caused the ring-buffer to recurse in a bad way. The bug was with the tracer I was writing and not the ring-buffer itself. But it took a long time to find the problem. This patch adds paranoid checks into the ring-buffer infrastructure that will catch bugs of this nature. Note: I put the bug back in the tracer and this patch showed the error nicely and prevented the lockup. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index cedf4e2..3f33806 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1022,8 +1022,23 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event; u64 ts, delta; int commit = 0; + int nr_loops = 0; again: + /* + * We allow for interrupts to reenter here and do a trace. + * If one does, it will cause this original code to loop + * back here. Even with heavy interrupts happening, this + * should only happen a few times in a row. If this happens + * 1000 times in a row, there must be either an interrupt + * storm or we have something buggy. + * Bail! + */ + if (unlikely(++nr_loops > 1000)) { + RB_WARN_ON(cpu_buffer, 1); + return NULL; + } + ts = ring_buffer_time_stamp(cpu_buffer->cpu); /* @@ -1532,10 +1547,23 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { struct buffer_page *reader = NULL; unsigned long flags; + int nr_loops = 0; spin_lock_irqsave(&cpu_buffer->lock, flags); again: + /* + * This should normally only loop twice. But because the + * start of the reader inserts an empty page, it causes + * a case where we will loop three times. There should be no + * reason to loop four times (that I know of). + */ + if (unlikely(++nr_loops > 3)) { + RB_WARN_ON(cpu_buffer, 1); + reader = NULL; + goto out; + } + reader = cpu_buffer->reader_page; /* If there's more to read, return this page */ @@ -1665,6 +1693,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; struct buffer_page *reader; + int nr_loops = 0; if (!cpu_isset(cpu, buffer->cpumask)) return NULL; @@ -1672,6 +1701,19 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) cpu_buffer = buffer->buffers[cpu]; again: + /* + * We repeat when a timestamp is encountered. It is possible + * to get multiple timestamps from an interrupt entering just + * as one timestamp is about to be written. The max times + * that this can happen is the number of nested interrupts we + * can have. Nesting 10 deep of interrupts is clearly + * an anomaly. + */ + if (unlikely(++nr_loops > 10)) { + RB_WARN_ON(cpu_buffer, 1); + return NULL; + } + reader = rb_get_reader_page(cpu_buffer); if (!reader) return NULL; @@ -1722,6 +1764,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) struct ring_buffer *buffer; struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; + int nr_loops = 0; if (ring_buffer_iter_empty(iter)) return NULL; @@ -1730,6 +1773,19 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) buffer = cpu_buffer->buffer; again: + /* + * We repeat when a timestamp is encountered. It is possible + * to get multiple timestamps from an interrupt entering just + * as one timestamp is about to be written. The max times + * that this can happen is the number of nested interrupts we + * can have. Nesting 10 deep of interrupts is clearly + * an anomaly. + */ + if (unlikely(++nr_loops > 10)) { + RB_WARN_ON(cpu_buffer, 1); + return NULL; + } + if (rb_per_cpu_empty(cpu_buffer)) return NULL; -- cgit v1.1 From f4b6755fb37595da3630d1d6fc130ea6888cd48f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Nov 2008 21:25:07 +0100 Subject: sched: cleanup fair task selection Impact: cleanup Clean up task selection Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 33 +++++++++++---------------------- 1 file changed, 11 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ce514af..6167336 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -347,17 +347,17 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) rb_erase(&se->run_node, &cfs_rq->tasks_timeline); } -static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq) -{ - return cfs_rq->rb_leftmost; -} - static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq) { - return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node); + struct rb_node *left = cfs_rq->rb_leftmost; + + if (!left) + return NULL; + + return rb_entry(left, struct sched_entity, run_node); } -static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) +static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) { struct rb_node *last = rb_last(&cfs_rq->tasks_timeline); @@ -794,28 +794,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) static int wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); -static struct sched_entity * -pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) +static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) { + struct sched_entity *se = __pick_next_entity(cfs_rq); + if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1) return se; return cfs_rq->next; } -static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) -{ - struct sched_entity *se = NULL; - - if (first_fair(cfs_rq)) { - se = __pick_next_entity(cfs_rq); - se = pick_next(cfs_rq, se); - set_next_entity(cfs_rq, se); - } - - return se; -} - static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) { /* @@ -1396,6 +1384,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq) do { se = pick_next_entity(cfs_rq); + set_next_entity(cfs_rq, se); cfs_rq = group_cfs_rq(se); } while (cfs_rq); -- cgit v1.1 From d95f98d0691d3aba5e35850011946a08c9b36428 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Nov 2008 21:25:08 +0100 Subject: sched: fix fair preempt check Impact: fix cross-class preemption Inter-class wakeup preemptions should go on class order. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6167336..ebd6de8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1329,6 +1329,9 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) return; } + if (unlikely(p->sched_class != &fair_sched_class)) + return; + if (unlikely(se == pse)) return; -- cgit v1.1 From 4793241be408b3926ee00c704d7da3b3faf3a05f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Nov 2008 21:25:09 +0100 Subject: sched: backward looking buddy Impact: improve/change/fix wakeup-buddy scheduling Currently we only have a forward looking buddy, that is, we prefer to schedule to the task we last woke up, under the presumption that its going to consume the data we just produced, and therefore will have cache hot benefits. This allows co-waking producer/consumer task pairs to run ahead of the pack for a little while, keeping their cache warm. Without this, we would interleave all pairs, utterly trashing the cache. This patch introduces a backward looking buddy, that is, suppose that in the above scenario, the consumer preempts the producer before it can go to sleep, we will therefore miss the wakeup from consumer to producer (its already running, after all), breaking the cycle and reverting to the cache-trashing interleaved schedule pattern. The backward buddy will try to schedule back to the task that woke us up in case the forward buddy is not available, under the assumption that the last task will be the one with the most cache hot task around barring current. This will basically allow a task to continue after it got preempted. In order to avoid starvation, we allow either buddy to get wakeup_gran ahead of the pack. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched.c | 6 ++++-- kernel/sched_fair.c | 32 +++++++++++++++++++++++++------- kernel/sched_features.h | 1 + 3 files changed, 30 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index e8819bc..82cc839 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -397,7 +397,7 @@ struct cfs_rq { * 'curr' points to currently running entity on this cfs_rq. * It is set to NULL otherwise (i.e when none are currently running). */ - struct sched_entity *curr, *next; + struct sched_entity *curr, *next, *last; unsigned long nr_spread_over; @@ -1805,7 +1805,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) /* * Buddy candidates are cache hot: */ - if (sched_feat(CACHE_HOT_BUDDY) && (&p->se == cfs_rq_of(&p->se)->next)) + if (sched_feat(CACHE_HOT_BUDDY) && + (&p->se == cfs_rq_of(&p->se)->next || + &p->se == cfs_rq_of(&p->se)->last)) return 1; if (p->sched_class != &fair_sched_class) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ebd6de8..a6b1db8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -341,9 +341,6 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) cfs_rq->rb_leftmost = next_node; } - if (cfs_rq->next == se) - cfs_rq->next = NULL; - rb_erase(&se->run_node, &cfs_rq->tasks_timeline); } @@ -741,6 +738,12 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) #endif } + if (cfs_rq->last == se) + cfs_rq->last = NULL; + + if (cfs_rq->next == se) + cfs_rq->next = NULL; + if (se != cfs_rq->curr) __dequeue_entity(cfs_rq, se); account_entity_dequeue(cfs_rq, se); @@ -798,10 +801,13 @@ static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) { struct sched_entity *se = __pick_next_entity(cfs_rq); - if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1) - return se; + if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1) + return cfs_rq->next; - return cfs_rq->next; + if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1) + return cfs_rq->last; + + return se; } static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) @@ -1319,10 +1325,11 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) { struct task_struct *curr = rq->curr; - struct cfs_rq *cfs_rq = task_cfs_rq(curr); struct sched_entity *se = &curr->se, *pse = &p->se; if (unlikely(rt_prio(p->prio))) { + struct cfs_rq *cfs_rq = task_cfs_rq(curr); + update_rq_clock(rq); update_curr(cfs_rq); resched_task(curr); @@ -1335,6 +1342,17 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) if (unlikely(se == pse)) return; + /* + * Only set the backward buddy when the current task is still on the + * rq. This can happen when a wakeup gets interleaved with schedule on + * the ->pre_schedule() or idle_balance() point, either of which can + * drop the rq lock. + * + * Also, during early boot the idle thread is in the fair class, for + * obvious reasons its a bad idea to schedule back to the idle thread. + */ + if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) + cfs_rq_of(se)->last = se; cfs_rq_of(pse)->next = pse; /* diff --git a/kernel/sched_features.h b/kernel/sched_features.h index fda0162..da5d93b 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -12,3 +12,4 @@ SCHED_FEAT(LB_BIAS, 1) SCHED_FEAT(LB_WAKEUP_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) SCHED_FEAT(WAKEUP_OVERLAP, 0) +SCHED_FEAT(LAST_BUDDY, 1) -- cgit v1.1 From 02479099c286894644f8e96c6bbb535ab64662fd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Nov 2008 21:25:10 +0100 Subject: sched: fix buddies for group scheduling Impact: scheduling order fix for group scheduling For each level in the hierarchy, set the buddy to point to the right entity. Therefore, when we do the hierarchical schedule, we have a fair chance of ending up where we meant to. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a6b1db8..51aa3e1 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1319,6 +1319,18 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) return 0; } +static void set_last_buddy(struct sched_entity *se) +{ + for_each_sched_entity(se) + cfs_rq_of(se)->last = se; +} + +static void set_next_buddy(struct sched_entity *se) +{ + for_each_sched_entity(se) + cfs_rq_of(se)->next = se; +} + /* * Preempt the current task with a newly woken task if needed: */ @@ -1352,8 +1364,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) * obvious reasons its a bad idea to schedule back to the idle thread. */ if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) - cfs_rq_of(se)->last = se; - cfs_rq_of(pse)->next = pse; + set_last_buddy(se); + set_next_buddy(pse); /* * We can come here with TIF_NEED_RESCHED already set from new task -- cgit v1.1 From 561920a0d2bb6d63343e83acfd784c0a77bd28d1 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 30 Oct 2008 18:28:41 +0100 Subject: generic-ipi: fix the smp_mb() placement smp_mb() is needed (to make the memory operations visible globally) before sending the ipi on the sender and the receiver (on Alpha atleast) needs smp_read_barrier_depends() in the handler before reading the call_single_queue list in a lock-free fashion. On x86, x2apic mode register accesses for sending IPI's don't have serializing semantics. So the need for smp_mb() before sending the IPI becomes more critical in x2apic mode. Remove the unnecessary smp_mb() in csd_flag_wait(), as the presence of that smp_mb() doesn't mean anything on the sender, when the ipi receiver is not doing any thing special (like memory fence) after clearing the CSD_FLAG_WAIT. Signed-off-by: Suresh Siddha Signed-off-by: Jens Axboe --- kernel/smp.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/smp.c b/kernel/smp.c index f362a85..75c8dde 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -51,10 +51,6 @@ static void csd_flag_wait(struct call_single_data *data) { /* Wait for response */ do { - /* - * We need to see the flags store in the IPI handler - */ - smp_mb(); if (!(data->flags & CSD_FLAG_WAIT)) break; cpu_relax(); @@ -76,6 +72,11 @@ static void generic_exec_single(int cpu, struct call_single_data *data) list_add_tail(&data->list, &dst->list); spin_unlock_irqrestore(&dst->lock, flags); + /* + * Make the list addition visible before sending the ipi. + */ + smp_mb(); + if (ipi) arch_send_call_function_single_ipi(cpu); @@ -157,7 +158,7 @@ void generic_smp_call_function_single_interrupt(void) * Need to see other stores to list head for checking whether * list is empty without holding q->lock */ - smp_mb(); + smp_read_barrier_depends(); while (!list_empty(&q->list)) { unsigned int data_flags; @@ -191,7 +192,7 @@ void generic_smp_call_function_single_interrupt(void) /* * See comment on outer loop */ - smp_mb(); + smp_read_barrier_depends(); } } @@ -370,6 +371,11 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info, list_add_tail_rcu(&data->csd.list, &call_function_queue); spin_unlock_irqrestore(&call_function_lock, flags); + /* + * Make the list addition visible before sending the ipi. + */ + smp_mb(); + /* Send a message to all CPUs in the map */ arch_send_call_function_ipi(mask); -- cgit v1.1 From 9c133c469d38043d5aadaa03f2fb840d88d1cf4f Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 6 Nov 2008 08:42:48 +0100 Subject: Add round_jiffies_up and related routines This patch (as1158b) adds round_jiffies_up() and friends. These routines work like the analogous round_jiffies() functions, except that they will never round down. The new routines will be useful for timeouts where we don't care exactly when the timer expires, provided it doesn't expire too soon. Signed-off-by: Alan Stern Signed-off-by: Jens Axboe --- kernel/timer.c | 129 +++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 99 insertions(+), 30 deletions(-) (limited to 'kernel') diff --git a/kernel/timer.c b/kernel/timer.c index 56becf3..dbd50fa 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -112,27 +112,8 @@ timer_set_base(struct timer_list *timer, struct tvec_base *new_base) tbase_get_deferrable(timer->base)); } -/** - * __round_jiffies - function to round jiffies to a full second - * @j: the time in (absolute) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * __round_jiffies() rounds an absolute time in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The exact rounding is skewed for each processor to avoid all - * processors firing at the exact same time, which could lead - * to lock contention or spurious cache line bouncing. - * - * The return value is the rounded version of the @j parameter. - */ -unsigned long __round_jiffies(unsigned long j, int cpu) +static unsigned long round_jiffies_common(unsigned long j, int cpu, + bool force_up) { int rem; unsigned long original = j; @@ -154,8 +135,9 @@ unsigned long __round_jiffies(unsigned long j, int cpu) * due to delays of the timer irq, long irq off times etc etc) then * we should round down to the whole second, not up. Use 1/4th second * as cutoff for this rounding as an extreme upper bound for this. + * But never round down if @force_up is set. */ - if (rem < HZ/4) /* round down */ + if (rem < HZ/4 && !force_up) /* round down */ j = j - rem; else /* round up */ j = j - rem + HZ; @@ -167,6 +149,31 @@ unsigned long __round_jiffies(unsigned long j, int cpu) return original; return j; } + +/** + * __round_jiffies - function to round jiffies to a full second + * @j: the time in (absolute) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * __round_jiffies() rounds an absolute time in the future (in jiffies) + * up or down to (approximately) full seconds. This is useful for timers + * for which the exact time they fire does not matter too much, as long as + * they fire approximately every X seconds. + * + * By rounding these timers to whole seconds, all such timers will fire + * at the same time, rather than at various times spread out. The goal + * of this is to have the CPU wake up less, which saves power. + * + * The exact rounding is skewed for each processor to avoid all + * processors firing at the exact same time, which could lead + * to lock contention or spurious cache line bouncing. + * + * The return value is the rounded version of the @j parameter. + */ +unsigned long __round_jiffies(unsigned long j, int cpu) +{ + return round_jiffies_common(j, cpu, false); +} EXPORT_SYMBOL_GPL(__round_jiffies); /** @@ -191,13 +198,10 @@ EXPORT_SYMBOL_GPL(__round_jiffies); */ unsigned long __round_jiffies_relative(unsigned long j, int cpu) { - /* - * In theory the following code can skip a jiffy in case jiffies - * increments right between the addition and the later subtraction. - * However since the entire point of this function is to use approximate - * timeouts, it's entirely ok to not handle that. - */ - return __round_jiffies(j + jiffies, cpu) - jiffies; + unsigned long j0 = jiffies; + + /* Use j0 because jiffies might change while we run */ + return round_jiffies_common(j + j0, cpu, false) - j0; } EXPORT_SYMBOL_GPL(__round_jiffies_relative); @@ -218,7 +222,7 @@ EXPORT_SYMBOL_GPL(__round_jiffies_relative); */ unsigned long round_jiffies(unsigned long j) { - return __round_jiffies(j, raw_smp_processor_id()); + return round_jiffies_common(j, raw_smp_processor_id(), false); } EXPORT_SYMBOL_GPL(round_jiffies); @@ -243,6 +247,71 @@ unsigned long round_jiffies_relative(unsigned long j) } EXPORT_SYMBOL_GPL(round_jiffies_relative); +/** + * __round_jiffies_up - function to round jiffies up to a full second + * @j: the time in (absolute) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * This is the same as __round_jiffies() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long __round_jiffies_up(unsigned long j, int cpu) +{ + return round_jiffies_common(j, cpu, true); +} +EXPORT_SYMBOL_GPL(__round_jiffies_up); + +/** + * __round_jiffies_up_relative - function to round jiffies up to a full second + * @j: the time in (relative) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * This is the same as __round_jiffies_relative() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long __round_jiffies_up_relative(unsigned long j, int cpu) +{ + unsigned long j0 = jiffies; + + /* Use j0 because jiffies might change while we run */ + return round_jiffies_common(j + j0, cpu, true) - j0; +} +EXPORT_SYMBOL_GPL(__round_jiffies_up_relative); + +/** + * round_jiffies_up - function to round jiffies up to a full second + * @j: the time in (absolute) jiffies that should be rounded + * + * This is the same as round_jiffies() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long round_jiffies_up(unsigned long j) +{ + return round_jiffies_common(j, raw_smp_processor_id(), true); +} +EXPORT_SYMBOL_GPL(round_jiffies_up); + +/** + * round_jiffies_up_relative - function to round jiffies up to a full second + * @j: the time in (relative) jiffies that should be rounded + * + * This is the same as round_jiffies_relative() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long round_jiffies_up_relative(unsigned long j) +{ + return __round_jiffies_up_relative(j, raw_smp_processor_id()); +} +EXPORT_SYMBOL_GPL(round_jiffies_up_relative); + static inline void set_running_timer(struct tvec_base *base, struct timer_list *timer) -- cgit v1.1 From 2d3854a37e8b767a51aba38ed6d22817b0631e33 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 5 Nov 2008 13:39:10 +1100 Subject: cpumask: introduce new API, without changing anything Impact: introduce new APIs We want to deprecate cpumasks on the stack, as we are headed for gynormous numbers of CPUs. Eventually, we want to head towards an undefined 'struct cpumask' so they can never be declared on stack. 1) New cpumask functions which take pointers instead of copies. (cpus_* -> cpumask_*) 2) Several new helpers to reduce requirements for temporary cpumasks (cpumask_first_and, cpumask_next_and, cpumask_any_and) 3) Helpers for declaring cpumasks on or offstack for large NR_CPUS (cpumask_var_t, alloc_cpumask_var and free_cpumask_var) 4) 'struct cpumask' for explicitness and to mark new-style code. 5) Make iterator functions stop at nr_cpu_ids (a runtime constant), not NR_CPUS for time efficiency and for smaller dynamic allocations in future. 6) cpumask_copy() so we can allocate less than a full cpumask eventually (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask' definition eventually. 7) work_on_cpu() helper for doing task on a CPU, rather than saving old cpumask for current thread and manipulating it. 8) smp_call_function_many() which is smp_call_function_mask() except taking a cpumask pointer. Note that this patch simply introduces the new functions and leaves the obsolescent ones in place. This is to simplify the transition patches. Signed-off-by: Rusty Russell Signed-off-by: Ingo Molnar --- kernel/cpu.c | 3 +++ kernel/workqueue.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index 86d4904..5a732c5 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -499,3 +499,6 @@ const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { #endif }; EXPORT_SYMBOL_GPL(cpu_bit_bitmap); + +const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; +EXPORT_SYMBOL(cpu_all_bits); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index f928f2a..d4dc69d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -970,6 +970,51 @@ undo: return ret; } +#ifdef CONFIG_SMP +struct work_for_cpu { + struct work_struct work; + long (*fn)(void *); + void *arg; + long ret; +}; + +static void do_work_for_cpu(struct work_struct *w) +{ + struct work_for_cpu *wfc = container_of(w, struct work_for_cpu, work); + + wfc->ret = wfc->fn(wfc->arg); +} + +/** + * work_on_cpu - run a function in user context on a particular cpu + * @cpu: the cpu to run on + * @fn: the function to run + * @arg: the function arg + * + * This will return -EINVAL in the cpu is not online, or the return value + * of @fn otherwise. + */ +long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) +{ + struct work_for_cpu wfc; + + INIT_WORK(&wfc.work, do_work_for_cpu); + wfc.fn = fn; + wfc.arg = arg; + get_online_cpus(); + if (unlikely(!cpu_online(cpu))) + wfc.ret = -EINVAL; + else { + schedule_work_on(cpu, &wfc.work); + flush_work(&wfc.work); + } + put_online_cpus(); + + return wfc.ret; +} +EXPORT_SYMBOL_GPL(work_on_cpu); +#endif /* CONFIG_SMP */ + void __init init_workqueues(void) { cpu_populated_map = cpu_online_map; -- cgit v1.1 From 24eb089950ce44603b30a3145a2c8520e2b55bb1 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 6 Nov 2008 12:53:32 -0800 Subject: cgroups: fix invalid cgrp->dentry before cgroup has been completely removed This fixes an oops when reading /proc/sched_debug. A cgroup won't be removed completely until finishing cgroup_diput(), so we shouldn't invalidate cgrp->dentry in cgroup_rmdir(). Otherwise, when a group is being removed while cgroup_path() gets called, we may trigger NULL dereference BUG. The bug can be reproduced: # cat test.sh #!/bin/sh mount -t cgroup -o cpu xxx /mnt for (( ; ; )) { mkdir /mnt/sub rmdir /mnt/sub } # ./test.sh & # cat /proc/sched_debug BUG: unable to handle kernel NULL pointer dereference at 00000038 IP: [] cgroup_path+0x39/0x90 ... Call Trace: [] ? print_cfs_rq+0x6e/0x75d [] ? sched_debug_show+0x72d/0xc1e ... Signed-off-by: Li Zefan Acked-by: Paul Menage Cc: Peter Zijlstra Cc: Ingo Molnar Cc: [2.6.26.x, 2.6.27.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 35eebd5..358e775 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2497,7 +2497,6 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry) list_del(&cgrp->sibling); spin_lock(&cgrp->dentry->d_lock); d = dget(cgrp->dentry); - cgrp->dentry = NULL; spin_unlock(&d->d_lock); cgroup_d_remove_dir(d); -- cgit v1.1 From f29c9b1ccb52904ee442a933cf3dee628f9f4e62 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 6 Nov 2008 09:45:16 +0800 Subject: sched: fix a bug in sched domain degenerate Impact: re-add incorrectly eliminated sched domain layers (1) on i386 with SCHED_SMT and SCHED_MC enabled # mount -t cgroup -o cpuset xxx /mnt # echo 0 > /mnt/cpuset.sched_load_balance # mkdir /mnt/0 # echo 0 > /mnt/0/cpuset.cpus # dmesg CPU0 attaching sched-domain: domain 0: span 0 level CPU groups: 0 (2) on i386 with SCHED_MC enabled but SCHED_SMT disabled # same with (1) # dmesg CPU0 attaching NULL sched-domain. The bug is that some sched domains may be skipped unintentionally when degenerating (optimizing) sched domains. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 82cc839..4c7e2bc 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6877,15 +6877,17 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) struct sched_domain *tmp; /* Remove the sched domains which do not contribute to scheduling. */ - for (tmp = sd; tmp; tmp = tmp->parent) { + for (tmp = sd; tmp; ) { struct sched_domain *parent = tmp->parent; if (!parent) break; + if (sd_parent_degenerate(tmp, parent)) { tmp->parent = parent->parent; if (parent->parent) parent->parent->child = tmp; - } + } else + tmp = tmp->parent; } if (sd && sd_degenerate(sd)) { -- cgit v1.1 From ca3273f9646694e0419cfb9d6c12deb1c9aff27c Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 7 Nov 2008 14:47:21 +0800 Subject: sched: fix memory leak in a failure path Impact: fix rare memory leak in the sched-domains manual reconfiguration code In the failure path, rd is not attached to a sched domain, so it causes a leak. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 4c7e2bc..57c933f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7676,6 +7676,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, error: free_sched_groups(cpu_map, tmpmask); SCHED_CPUMASK_FREE((void *)allmasks); + kfree(rd); return -ENOMEM; #endif } -- cgit v1.1