diff options
49 files changed, 837 insertions, 1049 deletions
@@ -2,8 +2,9 @@ # Kbuild for top-level directory of the kernel # This file takes care of the following: # 1) Generate bounds.h -# 2) Generate asm-offsets.h (may need bounds.h) -# 3) Check for missing system calls +# 2) Generate timeconst.h +# 3) Generate asm-offsets.h (may need bounds.h and timeconst.h) +# 4) Check for missing system calls # Default sed regexp - multiline due to syntax constraints define sed-y @@ -47,7 +48,26 @@ $(obj)/$(bounds-file): kernel/bounds.s FORCE $(call filechk,offsets,__LINUX_BOUNDS_H__) ##### -# 2) Generate asm-offsets.h +# 2) Generate timeconst.h + +timeconst-file := include/generated/timeconst.h + +#always += $(timeconst-file) +targets += $(timeconst-file) + +quiet_cmd_gentimeconst = GEN $@ +define cmd_gentimeconst + (echo $(CONFIG_HZ) | bc -q $< ) > $@ +endef +define filechk_gentimeconst + (echo $(CONFIG_HZ) | bc -q $< ) +endef + +$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE + $(call filechk,gentimeconst) + +##### +# 3) Generate asm-offsets.h # offsets-file := include/generated/asm-offsets.h @@ -57,7 +77,7 @@ targets += arch/$(SRCARCH)/kernel/asm-offsets.s # We use internal kbuild rules to avoid the "is up to date" message from make arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \ - $(obj)/$(bounds-file) FORCE + $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c) @@ -65,7 +85,7 @@ $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE $(call filechk,offsets,__ASM_OFFSETS_H__) ##### -# 3) Check for missing system calls +# 4) Check for missing system calls # always += missing-syscalls @@ -77,5 +97,5 @@ quiet_cmd_syscalls = CALL $< missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE $(call cmd,syscalls) -# Keep these two files during make clean -no-clean-files := $(bounds-file) $(offsets-file) +# Keep these three files during make clean +no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file) diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index 358c54a..5cbd4e6 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -204,9 +204,8 @@ again: static void rapl_start_hrtimer(struct rapl_pmu *pmu) { - __hrtimer_start_range_ns(&pmu->hrtimer, - pmu->timer_interval, 0, - HRTIMER_MODE_REL_PINNED, 0); + hrtimer_start(&pmu->hrtimer, pmu->timer_interval, + HRTIMER_MODE_REL_PINNED); } static void rapl_stop_hrtimer(struct rapl_pmu *pmu) diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index c635b8b..7c411f0 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -233,9 +233,8 @@ static enum hrtimer_restart uncore_pmu_hrtimer(struct hrtimer *hrtimer) void uncore_pmu_start_hrtimer(struct intel_uncore_box *box) { - __hrtimer_start_range_ns(&box->hrtimer, - ns_to_ktime(box->hrtimer_duration), 0, - HRTIMER_MODE_REL_PINNED, 0); + hrtimer_start(&box->hrtimer, ns_to_ktime(box->hrtimer_duration), + HRTIMER_MODE_REL_PINNED); } void uncore_pmu_cancel_hrtimer(struct intel_uncore_box *box) diff --git a/drivers/clocksource/asm9260_timer.c b/drivers/clocksource/asm9260_timer.c index 2c9c993..4c2ba59 100644 --- a/drivers/clocksource/asm9260_timer.c +++ b/drivers/clocksource/asm9260_timer.c @@ -178,7 +178,7 @@ static void __init asm9260_timer_init(struct device_node *np) unsigned long rate; priv.base = of_io_request_and_map(np, 0, np->name); - if (!priv.base) + if (IS_ERR(priv.base)) panic("%s: unable to map resource", np->name); clk = of_clk_get(np, 0); diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c index b9efd30..c97d198 100644 --- a/drivers/clocksource/timer-integrator-ap.c +++ b/drivers/clocksource/timer-integrator-ap.c @@ -166,7 +166,7 @@ static void __init integrator_ap_timer_init_of(struct device_node *node) struct device_node *sec_node; base = of_io_request_and_map(node, 0, "integrator-timer"); - if (!base) + if (IS_ERR(base)) return; clk = of_clk_get(node, 0); diff --git a/drivers/clocksource/timer-sun5i.c b/drivers/clocksource/timer-sun5i.c index 28aa4b7..0ffb4ea 100644 --- a/drivers/clocksource/timer-sun5i.c +++ b/drivers/clocksource/timer-sun5i.c @@ -324,7 +324,7 @@ static void __init sun5i_timer_init(struct device_node *node) int irq; timer_base = of_io_request_and_map(node, 0, of_node_full_name(node)); - if (!timer_base) + if (IS_ERR(timer_base)) panic("Can't map registers"); irq = irq_of_parse_and_map(node, 0); diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c index 1e08195..5f855f9 100644 --- a/drivers/power/reset/ltc2952-poweroff.c +++ b/drivers/power/reset/ltc2952-poweroff.c @@ -158,7 +158,6 @@ static irqreturn_t ltc2952_poweroff_handler(int irq, void *dev_id) HRTIMER_MODE_REL); } else { hrtimer_cancel(&data->timer_trigger); - /* omitting return value check, timer should have been valid */ } return IRQ_HANDLED; } diff --git a/include/linux/alarmtimer.h b/include/linux/alarmtimer.h index a899402..52f3b7d 100644 --- a/include/linux/alarmtimer.h +++ b/include/linux/alarmtimer.h @@ -43,8 +43,8 @@ struct alarm { void alarm_init(struct alarm *alarm, enum alarmtimer_type type, enum alarmtimer_restart (*function)(struct alarm *, ktime_t)); -int alarm_start(struct alarm *alarm, ktime_t start); -int alarm_start_relative(struct alarm *alarm, ktime_t start); +void alarm_start(struct alarm *alarm, ktime_t start); +void alarm_start_relative(struct alarm *alarm, ktime_t start); void alarm_restart(struct alarm *alarm); int alarm_try_to_cancel(struct alarm *alarm); int alarm_cancel(struct alarm *alarm); diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index d27d015..278dd27 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -181,7 +181,6 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift) extern int clocksource_unregister(struct clocksource*); extern void clocksource_touch_watchdog(void); -extern struct clocksource* clocksource_get_next(void); extern void clocksource_change_rating(struct clocksource *cs, int rating); extern void clocksource_suspend(void); extern void clocksource_resume(void); diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 05f6df1..470d876 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -130,6 +130,12 @@ struct hrtimer_sleeper { struct task_struct *task; }; +#ifdef CONFIG_64BIT +# define HRTIMER_CLOCK_BASE_ALIGN 64 +#else +# define HRTIMER_CLOCK_BASE_ALIGN 32 +#endif + /** * struct hrtimer_clock_base - the timer base for a specific clock * @cpu_base: per cpu clock base @@ -137,9 +143,7 @@ struct hrtimer_sleeper { * timer to a base on another cpu. * @clockid: clock id for per_cpu support * @active: red black tree root node for the active timers - * @resolution: the resolution of the clock, in nanoseconds * @get_time: function to retrieve the current time of the clock - * @softirq_time: the time when running the hrtimer queue in the softirq * @offset: offset of this clock to the monotonic base */ struct hrtimer_clock_base { @@ -147,11 +151,9 @@ struct hrtimer_clock_base { int index; clockid_t clockid; struct timerqueue_head active; - ktime_t resolution; ktime_t (*get_time)(void); - ktime_t softirq_time; ktime_t offset; -}; +} __attribute__((__aligned__(HRTIMER_CLOCK_BASE_ALIGN))); enum hrtimer_base_type { HRTIMER_BASE_MONOTONIC, @@ -167,9 +169,10 @@ enum hrtimer_base_type { * and timers * @cpu: cpu number * @active_bases: Bitfield to mark bases with active timers - * @clock_was_set: Indicates that clock was set from irq context. + * @clock_was_set_seq: Sequence counter of clock was set events * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() + * @next_timer: Pointer to the first expiring timer * @in_hrtirq: hrtimer_interrupt() is currently executing * @hres_active: State of high resolution mode * @hang_detected: The last hrtimer interrupt detected a hang @@ -178,27 +181,34 @@ enum hrtimer_base_type { * @nr_hangs: Total number of hrtimer interrupt hangs * @max_hang_time: Maximum time spent in hrtimer_interrupt * @clock_base: array of clock bases for this cpu + * + * Note: next_timer is just an optimization for __remove_hrtimer(). + * Do not dereference the pointer because it is not reliable on + * cross cpu removals. */ struct hrtimer_cpu_base { raw_spinlock_t lock; unsigned int cpu; unsigned int active_bases; - unsigned int clock_was_set; + unsigned int clock_was_set_seq; #ifdef CONFIG_HIGH_RES_TIMERS + unsigned int in_hrtirq : 1, + hres_active : 1, + hang_detected : 1; ktime_t expires_next; - int in_hrtirq; - int hres_active; - int hang_detected; - unsigned long nr_events; - unsigned long nr_retries; - unsigned long nr_hangs; - ktime_t max_hang_time; + struct hrtimer *next_timer; + unsigned int nr_events; + unsigned int nr_retries; + unsigned int nr_hangs; + unsigned int max_hang_time; #endif struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; -}; +} ____cacheline_aligned; static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) { + BUILD_BUG_ON(sizeof(struct hrtimer_clock_base) > HRTIMER_CLOCK_BASE_ALIGN); + timer->node.expires = time; timer->_softexpires = time; } @@ -262,19 +272,16 @@ static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) return ktime_sub(timer->node.expires, timer->base->get_time()); } -#ifdef CONFIG_HIGH_RES_TIMERS -struct clock_event_device; - -extern void hrtimer_interrupt(struct clock_event_device *dev); - -/* - * In high resolution mode the time reference must be read accurate - */ static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) { return timer->base->get_time(); } +#ifdef CONFIG_HIGH_RES_TIMERS +struct clock_event_device; + +extern void hrtimer_interrupt(struct clock_event_device *dev); + static inline int hrtimer_is_hres_active(struct hrtimer *timer) { return timer->base->cpu_base->hres_active; @@ -295,21 +302,16 @@ extern void hrtimer_peek_ahead_timers(void); extern void clock_was_set_delayed(void); +extern unsigned int hrtimer_resolution; + #else # define MONOTONIC_RES_NSEC LOW_RES_NSEC # define KTIME_MONOTONIC_RES KTIME_LOW_RES -static inline void hrtimer_peek_ahead_timers(void) { } +#define hrtimer_resolution LOW_RES_NSEC -/* - * In non high resolution mode the time reference is taken from - * the base softirq time variable. - */ -static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) -{ - return timer->base->softirq_time; -} +static inline void hrtimer_peek_ahead_timers(void) { } static inline int hrtimer_is_hres_active(struct hrtimer *timer) { @@ -353,39 +355,45 @@ static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } #endif /* Basic timer operations: */ -extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, - const enum hrtimer_mode mode); -extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, +extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long range_ns, const enum hrtimer_mode mode); -extern int -__hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, - unsigned long delta_ns, - const enum hrtimer_mode mode, int wakeup); + +/** + * hrtimer_start - (re)start an hrtimer on the current CPU + * @timer: the timer to be added + * @tim: expiry time + * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or + * relative (HRTIMER_MODE_REL) + */ +static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim, + const enum hrtimer_mode mode) +{ + hrtimer_start_range_ns(timer, tim, 0, mode); +} extern int hrtimer_cancel(struct hrtimer *timer); extern int hrtimer_try_to_cancel(struct hrtimer *timer); -static inline int hrtimer_start_expires(struct hrtimer *timer, - enum hrtimer_mode mode) +static inline void hrtimer_start_expires(struct hrtimer *timer, + enum hrtimer_mode mode) { unsigned long delta; ktime_t soft, hard; soft = hrtimer_get_softexpires(timer); hard = hrtimer_get_expires(timer); delta = ktime_to_ns(ktime_sub(hard, soft)); - return hrtimer_start_range_ns(timer, soft, delta, mode); + hrtimer_start_range_ns(timer, soft, delta, mode); } -static inline int hrtimer_restart(struct hrtimer *timer) +static inline void hrtimer_restart(struct hrtimer *timer) { - return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); + hrtimer_start_expires(timer, HRTIMER_MODE_ABS); } /* Query timers: */ extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); -extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); -extern ktime_t hrtimer_get_next_event(void); +extern u64 hrtimer_get_next_event(void); /* * A timer is active, when it is enqueued into the rbtree or the @@ -418,7 +426,22 @@ static inline int hrtimer_callback_running(struct hrtimer *timer) extern u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); -/* Forward a hrtimer so it expires after the hrtimer's current now */ +/** + * hrtimer_forward_now - forward the timer expiry so it expires after now + * @timer: hrtimer to forward + * @interval: the interval to forward + * + * Forward the timer expiry so it will expire after the current time + * of the hrtimer clock base. Returns the number of overruns. + * + * Can be safely called from the callback function of @timer. If + * called from other contexts @timer must neither be enqueued nor + * running the callback and the caller needs to take care of + * serialization. + * + * Note: This only updates the timer expiry value and does not requeue + * the timer. + */ static inline u64 hrtimer_forward_now(struct hrtimer *timer, ktime_t interval) { @@ -443,7 +466,6 @@ extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); /* Soft interrupt function to run the hrtimer queues: */ extern void hrtimer_run_queues(void); -extern void hrtimer_run_pending(void); /* Bootup initialization: */ extern void __init hrtimers_init(void); diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 950ae45..be7e75c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -413,7 +413,8 @@ enum BLOCK_IOPOLL_SOFTIRQ, TASKLET_SOFTIRQ, SCHED_SOFTIRQ, - HRTIMER_SOFTIRQ, + HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the + numbering. Sigh! */ RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */ NR_SOFTIRQS @@ -592,10 +593,10 @@ tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer, clockid_t which_clock, enum hrtimer_mode mode); static inline -int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time, - const enum hrtimer_mode mode) +void tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time, + const enum hrtimer_mode mode) { - return hrtimer_start(&ttimer->timer, time, mode); + hrtimer_start(&ttimer->timer, time, mode); } static inline diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index c367cbd..5e75af6 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -7,6 +7,7 @@ #include <linux/time.h> #include <linux/timex.h> #include <asm/param.h> /* for HZ */ +#include <generated/timeconst.h> /* * The following defines establish the engineering parameters of the PLL @@ -288,7 +289,80 @@ static inline u64 jiffies_to_nsecs(const unsigned long j) return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; } -extern unsigned long msecs_to_jiffies(const unsigned int m); +extern unsigned long __msecs_to_jiffies(const unsigned int m); +#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) +/* + * HZ is equal to or smaller than 1000, and 1000 is a nice round + * multiple of HZ, divide with the factor between them, but round + * upwards: + */ +static inline unsigned long _msecs_to_jiffies(const unsigned int m) +{ + return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); +} +#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) +/* + * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - + * simply multiply with the factor between them. + * + * But first make sure the multiplication result cannot overflow: + */ +static inline unsigned long _msecs_to_jiffies(const unsigned int m) +{ + if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) + return MAX_JIFFY_OFFSET; + return m * (HZ / MSEC_PER_SEC); +} +#else +/* + * Generic case - multiply, round and divide. But first check that if + * we are doing a net multiplication, that we wouldn't overflow: + */ +static inline unsigned long _msecs_to_jiffies(const unsigned int m) +{ + if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) + return MAX_JIFFY_OFFSET; + + return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) + >> MSEC_TO_HZ_SHR32; +} +#endif +/** + * msecs_to_jiffies: - convert milliseconds to jiffies + * @m: time in milliseconds + * + * conversion is done as follows: + * + * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) + * + * - 'too large' values [that would result in larger than + * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. + * + * - all other values are converted to jiffies by either multiplying + * the input value by a factor or dividing it with a factor and + * handling any 32-bit overflows. + * for the details see __msecs_to_jiffies() + * + * msecs_to_jiffies() checks for the passed in value being a constant + * via __builtin_constant_p() allowing gcc to eliminate most of the + * code, __msecs_to_jiffies() is called if the value passed does not + * allow constant folding and the actual conversion must be done at + * runtime. + * the HZ range specific helpers _msecs_to_jiffies() are called both + * directly here and from __msecs_to_jiffies() in the case where + * constant folding is not possible. + */ +static inline unsigned long msecs_to_jiffies(const unsigned int m) +{ + if (__builtin_constant_p(m)) { + if ((int)m < 0) + return MAX_JIFFY_OFFSET; + return _msecs_to_jiffies(m); + } else { + return __msecs_to_jiffies(m); + } +} + extern unsigned long usecs_to_jiffies(const unsigned int u); extern unsigned long timespec_to_jiffies(const struct timespec *value); extern void jiffies_to_timespec(const unsigned long jiffies, diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 61992cf..cf3342a 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -566,8 +566,12 @@ struct perf_cpu_context { struct perf_event_context *task_ctx; int active_oncpu; int exclusive; + + raw_spinlock_t hrtimer_lock; struct hrtimer hrtimer; ktime_t hrtimer_interval; + unsigned int hrtimer_active; + struct pmu *unique_pmu; struct perf_cgroup *cgrp; }; diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 573a5af..0627a44 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -44,6 +44,8 @@ #include <linux/debugobjects.h> #include <linux/bug.h> #include <linux/compiler.h> +#include <linux/ktime.h> + #include <asm/barrier.h> extern int rcu_expedited; /* for sysctl */ @@ -1154,9 +1156,9 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) #if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) -static inline int rcu_needs_cpu(unsigned long *delta_jiffies) +static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt) { - *delta_jiffies = ULONG_MAX; + *nextevt = KTIME_MAX; return 0; } #endif /* #if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) */ diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index d2e583a..db2e31be 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -32,7 +32,7 @@ void rcu_note_context_switch(void); #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(unsigned long *delta_jiffies); +int rcu_needs_cpu(u64 basem, u64 *nextevt); #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ void rcu_cpu_stall_reset(void); diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index fb86963..6f8276a 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -49,6 +49,7 @@ struct tk_read_base { * @offs_boot: Offset clock monotonic -> clock boottime * @offs_tai: Offset clock monotonic -> clock tai * @tai_offset: The current UTC to TAI offset in seconds + * @clock_was_set_seq: The sequence number of clock was set events * @raw_time: Monotonic raw base time in timespec64 format * @cycle_interval: Number of clock cycles in one NTP interval * @xtime_interval: Number of clock shifted nano seconds in one NTP @@ -85,6 +86,7 @@ struct timekeeper { ktime_t offs_boot; ktime_t offs_tai; s32 tai_offset; + unsigned int clock_was_set_seq; struct timespec64 raw_time; /* The following members are for timekeeping internal use */ diff --git a/include/linux/timer.h b/include/linux/timer.h index 8c5a197..fbb80e0 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -188,13 +188,6 @@ extern void set_timer_slack(struct timer_list *time, int slack_hz); #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1) /* - * Return when the next timer-wheel timeout occurs (in absolute jiffies), - * locks the timer base and does the comparison against the given - * jiffie. - */ -extern unsigned long get_next_timer_interrupt(unsigned long now); - -/* * Timer-statistics info: */ #ifdef CONFIG_TIMER_STATS diff --git a/include/linux/timerqueue.h b/include/linux/timerqueue.h index a520fd7..7eec17a 100644 --- a/include/linux/timerqueue.h +++ b/include/linux/timerqueue.h @@ -16,10 +16,10 @@ struct timerqueue_head { }; -extern void timerqueue_add(struct timerqueue_head *head, - struct timerqueue_node *node); -extern void timerqueue_del(struct timerqueue_head *head, - struct timerqueue_node *node); +extern bool timerqueue_add(struct timerqueue_head *head, + struct timerqueue_node *node); +extern bool timerqueue_del(struct timerqueue_head *head, + struct timerqueue_node *node); extern struct timerqueue_node *timerqueue_iterate_next( struct timerqueue_node *node); diff --git a/kernel/events/core.c b/kernel/events/core.c index 1a3bf48..1c6c282 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -51,9 +51,11 @@ static struct workqueue_struct *perf_wq; +typedef int (*remote_function_f)(void *); + struct remote_function_call { struct task_struct *p; - int (*func)(void *info); + remote_function_f func; void *info; int ret; }; @@ -86,7 +88,7 @@ static void remote_function(void *data) * -EAGAIN - when the process moved away */ static int -task_function_call(struct task_struct *p, int (*func) (void *info), void *info) +task_function_call(struct task_struct *p, remote_function_f func, void *info) { struct remote_function_call data = { .p = p, @@ -110,7 +112,7 @@ task_function_call(struct task_struct *p, int (*func) (void *info), void *info) * * returns: @func return value or -ENXIO when the cpu is offline */ -static int cpu_function_call(int cpu, int (*func) (void *info), void *info) +static int cpu_function_call(int cpu, remote_function_f func, void *info) { struct remote_function_call data = { .p = NULL, @@ -747,62 +749,31 @@ perf_cgroup_mark_enabled(struct perf_event *event, /* * function must be called with interrupts disbled */ -static enum hrtimer_restart perf_cpu_hrtimer_handler(struct hrtimer *hr) +static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) { struct perf_cpu_context *cpuctx; - enum hrtimer_restart ret = HRTIMER_NORESTART; int rotations = 0; WARN_ON(!irqs_disabled()); cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); - rotations = perf_rotate_context(cpuctx); - /* - * arm timer if needed - */ - if (rotations) { + raw_spin_lock(&cpuctx->hrtimer_lock); + if (rotations) hrtimer_forward_now(hr, cpuctx->hrtimer_interval); - ret = HRTIMER_RESTART; - } - - return ret; -} - -/* CPU is going down */ -void perf_cpu_hrtimer_cancel(int cpu) -{ - struct perf_cpu_context *cpuctx; - struct pmu *pmu; - unsigned long flags; - - if (WARN_ON(cpu != smp_processor_id())) - return; - - local_irq_save(flags); - - rcu_read_lock(); - - list_for_each_entry_rcu(pmu, &pmus, entry) { - cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); - - if (pmu->task_ctx_nr == perf_sw_context) - continue; - - hrtimer_cancel(&cpuctx->hrtimer); - } - - rcu_read_unlock(); + else + cpuctx->hrtimer_active = 0; + raw_spin_unlock(&cpuctx->hrtimer_lock); - local_irq_restore(flags); + return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART; } -static void __perf_cpu_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) +static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) { - struct hrtimer *hr = &cpuctx->hrtimer; + struct hrtimer *timer = &cpuctx->hrtimer; struct pmu *pmu = cpuctx->ctx.pmu; - int timer; + u64 interval; /* no multiplexing needed for SW PMU */ if (pmu->task_ctx_nr == perf_sw_context) @@ -812,31 +783,36 @@ static void __perf_cpu_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) * check default is sane, if not set then force to * default interval (1/tick) */ - timer = pmu->hrtimer_interval_ms; - if (timer < 1) - timer = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; + interval = pmu->hrtimer_interval_ms; + if (interval < 1) + interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER; - cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); + cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); - hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED); - hr->function = perf_cpu_hrtimer_handler; + raw_spin_lock_init(&cpuctx->hrtimer_lock); + hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); + timer->function = perf_mux_hrtimer_handler; } -static void perf_cpu_hrtimer_restart(struct perf_cpu_context *cpuctx) +static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx) { - struct hrtimer *hr = &cpuctx->hrtimer; + struct hrtimer *timer = &cpuctx->hrtimer; struct pmu *pmu = cpuctx->ctx.pmu; + unsigned long flags; /* not for SW PMU */ if (pmu->task_ctx_nr == perf_sw_context) - return; + return 0; - if (hrtimer_active(hr)) - return; + raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags); + if (!cpuctx->hrtimer_active) { + cpuctx->hrtimer_active = 1; + hrtimer_forward_now(timer, cpuctx->hrtimer_interval); + hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); + } + raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags); - if (!hrtimer_callback_running(hr)) - __hrtimer_start_range_ns(hr, cpuctx->hrtimer_interval, - 0, HRTIMER_MODE_REL_PINNED, 0); + return 0; } void perf_pmu_disable(struct pmu *pmu) @@ -1935,7 +1911,7 @@ group_sched_in(struct perf_event *group_event, if (event_sched_in(group_event, cpuctx, ctx)) { pmu->cancel_txn(pmu); - perf_cpu_hrtimer_restart(cpuctx); + perf_mux_hrtimer_restart(cpuctx); return -EAGAIN; } @@ -1982,7 +1958,7 @@ group_error: pmu->cancel_txn(pmu); - perf_cpu_hrtimer_restart(cpuctx); + perf_mux_hrtimer_restart(cpuctx); return -EAGAIN; } @@ -2255,7 +2231,7 @@ static int __perf_event_enable(void *info) */ if (leader != event) { group_sched_out(leader, cpuctx, ctx); - perf_cpu_hrtimer_restart(cpuctx); + perf_mux_hrtimer_restart(cpuctx); } if (leader->attr.pinned) { update_group_times(leader); @@ -6863,9 +6839,8 @@ static void perf_swevent_start_hrtimer(struct perf_event *event) } else { period = max_t(u64, 10000, hwc->sample_period); } - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL_PINNED, 0); + hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), + HRTIMER_MODE_REL_PINNED); } static void perf_swevent_cancel_hrtimer(struct perf_event *event) @@ -7166,6 +7141,8 @@ perf_event_mux_interval_ms_show(struct device *dev, return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms); } +static DEFINE_MUTEX(mux_interval_mutex); + static ssize_t perf_event_mux_interval_ms_store(struct device *dev, struct device_attribute *attr, @@ -7185,17 +7162,21 @@ perf_event_mux_interval_ms_store(struct device *dev, if (timer == pmu->hrtimer_interval_ms) return count; + mutex_lock(&mux_interval_mutex); pmu->hrtimer_interval_ms = timer; /* update all cpuctx for this PMU */ - for_each_possible_cpu(cpu) { + get_online_cpus(); + for_each_online_cpu(cpu) { struct perf_cpu_context *cpuctx; cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer); - if (hrtimer_active(&cpuctx->hrtimer)) - hrtimer_forward_now(&cpuctx->hrtimer, cpuctx->hrtimer_interval); + cpu_function_call(cpu, + (remote_function_f)perf_mux_hrtimer_restart, cpuctx); } + put_online_cpus(); + mutex_unlock(&mux_interval_mutex); return count; } @@ -7300,7 +7281,7 @@ skip_type: lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); cpuctx->ctx.pmu = pmu; - __perf_cpu_hrtimer_init(cpuctx, cpu); + __perf_mux_hrtimer_init(cpuctx, cpu); cpuctx->unique_pmu = pmu; } diff --git a/kernel/futex.c b/kernel/futex.c index 2579e40..720eacf 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2063,11 +2063,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, queue_me(q, hb); /* Arm the timer */ - if (timeout) { + if (timeout) hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - if (!hrtimer_active(&timeout->timer)) - timeout->task = NULL; - } /* * If we have been removed from the hash list, then another task diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index b025295..8b678ca 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1182,11 +1182,8 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, set_current_state(state); /* Setup the timer, when timeout != NULL */ - if (unlikely(timeout)) { + if (unlikely(timeout)) hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - if (!hrtimer_active(&timeout->timer)) - timeout->task = NULL; - } ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 8c0ec0f..0ef80a0 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1368,9 +1368,9 @@ static void rcu_prepare_kthreads(int cpu) * any flavor of RCU. */ #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(unsigned long *delta_jiffies) +int rcu_needs_cpu(u64 basemono, u64 *nextevt) { - *delta_jiffies = ULONG_MAX; + *nextevt = KTIME_MAX; return rcu_cpu_has_callbacks(NULL); } #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ @@ -1481,16 +1481,17 @@ static bool __maybe_unused rcu_try_advance_all_cbs(void) * The caller must have disabled interrupts. */ #ifndef CONFIG_RCU_NOCB_CPU_ALL -int rcu_needs_cpu(unsigned long *dj) +int rcu_needs_cpu(u64 basemono, u64 *nextevt) { struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); + unsigned long dj; /* Snapshot to detect later posting of non-lazy callback. */ rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; /* If no callbacks, RCU doesn't need the CPU. */ if (!rcu_cpu_has_callbacks(&rdtp->all_lazy)) { - *dj = ULONG_MAX; + *nextevt = KTIME_MAX; return 0; } @@ -1504,11 +1505,12 @@ int rcu_needs_cpu(unsigned long *dj) /* Request timer delay depending on laziness, and round. */ if (!rdtp->all_lazy) { - *dj = round_up(rcu_idle_gp_delay + jiffies, + dj = round_up(rcu_idle_gp_delay + jiffies, rcu_idle_gp_delay) - jiffies; } else { - *dj = round_jiffies(rcu_idle_lazy_gp_delay + jiffies) - jiffies; + dj = round_jiffies(rcu_idle_lazy_gp_delay + jiffies) - jiffies; } + *nextevt = basemono + dj * TICK_NSEC; return 0; } #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 57bd333..ecb7c42 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -90,26 +90,6 @@ #define CREATE_TRACE_POINTS #include <trace/events/sched.h> -void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) -{ - unsigned long delta; - ktime_t soft, hard, now; - - for (;;) { - if (hrtimer_active(period_timer)) - break; - - now = hrtimer_cb_get_time(period_timer); - hrtimer_forward(period_timer, now, period); - - soft = hrtimer_get_softexpires(period_timer); - hard = hrtimer_get_expires(period_timer); - delta = ktime_to_ns(ktime_sub(hard, soft)); - __hrtimer_start_range_ns(period_timer, soft, delta, - HRTIMER_MODE_ABS_PINNED, 0); - } -} - DEFINE_MUTEX(sched_domains_mutex); DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); @@ -355,12 +335,11 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer) #ifdef CONFIG_SMP -static int __hrtick_restart(struct rq *rq) +static void __hrtick_restart(struct rq *rq) { struct hrtimer *timer = &rq->hrtick_timer; - ktime_t time = hrtimer_get_softexpires(timer); - return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0); + hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED); } /* @@ -440,8 +419,8 @@ void hrtick_start(struct rq *rq, u64 delay) * doesn't make sense. Rely on vruntime for fairness. */ delay = max_t(u64, delay, 10000LL); - __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, - HRTIMER_MODE_REL_PINNED, 0); + hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), + HRTIMER_MODE_REL_PINNED); } static inline void init_hrtick(void) @@ -8108,10 +8087,8 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) __refill_cfs_bandwidth_runtime(cfs_b); /* restart the period timer (if active) to handle new period expiry */ - if (runtime_enabled && cfs_b->timer_active) { - /* force a reprogram */ - __start_cfs_bandwidth(cfs_b, true); - } + if (runtime_enabled) + start_cfs_bandwidth(cfs_b); raw_spin_unlock_irq(&cfs_b->lock); for_each_online_cpu(i) { diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 5e95145..21d6907 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -503,8 +503,6 @@ static int start_dl_timer(struct sched_dl_entity *dl_se, bool boosted) struct dl_rq *dl_rq = dl_rq_of_se(dl_se); struct rq *rq = rq_of_dl_rq(dl_rq); ktime_t now, act; - ktime_t soft, hard; - unsigned long range; s64 delta; if (boosted) @@ -527,15 +525,9 @@ static int start_dl_timer(struct sched_dl_entity *dl_se, bool boosted) if (ktime_us_delta(act, now) < 0) return 0; - hrtimer_set_expires(&dl_se->dl_timer, act); + hrtimer_start(&dl_se->dl_timer, act, HRTIMER_MODE_ABS); - soft = hrtimer_get_softexpires(&dl_se->dl_timer); - hard = hrtimer_get_expires(&dl_se->dl_timer); - range = ktime_to_ns(ktime_sub(hard, soft)); - __hrtimer_start_range_ns(&dl_se->dl_timer, soft, - range, HRTIMER_MODE_ABS, 0); - - return hrtimer_active(&dl_se->dl_timer); + return 1; } /* diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index a245c1f..f94724e 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -230,8 +230,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) #endif #endif #ifdef CONFIG_CFS_BANDWIDTH - SEQ_printf(m, " .%-30s: %d\n", "tg->cfs_bandwidth.timer_active", - cfs_rq->tg->cfs_bandwidth.timer_active); SEQ_printf(m, " .%-30s: %d\n", "throttled", cfs_rq->throttled); SEQ_printf(m, " .%-30s: %d\n", "throttle_count", diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ffeaa41..69be282 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3476,16 +3476,7 @@ static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq) if (cfs_b->quota == RUNTIME_INF) amount = min_amount; else { - /* - * If the bandwidth pool has become inactive, then at least one - * period must have elapsed since the last consumption. - * Refresh the global state and ensure bandwidth timer becomes - * active. - */ - if (!cfs_b->timer_active) { - __refill_cfs_bandwidth_runtime(cfs_b); - __start_cfs_bandwidth(cfs_b, false); - } + start_cfs_bandwidth(cfs_b); if (cfs_b->runtime > 0) { amount = min(cfs_b->runtime, min_amount); @@ -3634,6 +3625,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); struct sched_entity *se; long task_delta, dequeue = 1; + bool empty; se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))]; @@ -3663,13 +3655,21 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->throttled = 1; cfs_rq->throttled_clock = rq_clock(rq); raw_spin_lock(&cfs_b->lock); + empty = list_empty(&cfs_rq->throttled_list); + /* * Add to the _head_ of the list, so that an already-started * distribute_cfs_runtime will not see us */ list_add_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); - if (!cfs_b->timer_active) - __start_cfs_bandwidth(cfs_b, false); + + /* + * If we're the first throttled task, make sure the bandwidth + * timer is running. + */ + if (empty) + start_cfs_bandwidth(cfs_b); + raw_spin_unlock(&cfs_b->lock); } @@ -3784,13 +3784,6 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) if (cfs_b->idle && !throttled) goto out_deactivate; - /* - * if we have relooped after returning idle once, we need to update our - * status as actually running, so that other cpus doing - * __start_cfs_bandwidth will stop trying to cancel us. - */ - cfs_b->timer_active = 1; - __refill_cfs_bandwidth_runtime(cfs_b); if (!throttled) { @@ -3835,7 +3828,6 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) return 0; out_deactivate: - cfs_b->timer_active = 0; return 1; } @@ -3850,7 +3842,7 @@ static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC; * Are we near the end of the current quota period? * * Requires cfs_b->lock for hrtimer_expires_remaining to be safe against the - * hrtimer base being cleared by __hrtimer_start_range_ns. In the case of + * hrtimer base being cleared by hrtimer_start. In the case of * migrate_hrtimers, base is never cleared, so we are fine. */ static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire) @@ -3878,8 +3870,9 @@ static void start_cfs_slack_bandwidth(struct cfs_bandwidth *cfs_b) if (runtime_refresh_within(cfs_b, min_left)) return; - start_bandwidth_timer(&cfs_b->slack_timer, - ns_to_ktime(cfs_bandwidth_slack_period)); + hrtimer_start(&cfs_b->slack_timer, + ns_to_ktime(cfs_bandwidth_slack_period), + HRTIMER_MODE_REL); } /* we know any runtime found here is valid as update_curr() precedes return */ @@ -3999,6 +3992,7 @@ static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer) { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, slack_timer); + do_sched_cfs_slack_timer(cfs_b); return HRTIMER_NORESTART; @@ -4008,20 +4002,19 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, period_timer); - ktime_t now; int overrun; int idle = 0; raw_spin_lock(&cfs_b->lock); for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, cfs_b->period); - + overrun = hrtimer_forward_now(timer, cfs_b->period); if (!overrun) break; idle = do_sched_cfs_period_timer(cfs_b, overrun); } + if (idle) + cfs_b->period_active = 0; raw_spin_unlock(&cfs_b->lock); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; @@ -4035,7 +4028,7 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) cfs_b->period = ns_to_ktime(default_cfs_period()); INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); - hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); cfs_b->period_timer.function = sched_cfs_period_timer; hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cfs_b->slack_timer.function = sched_cfs_slack_timer; @@ -4047,28 +4040,15 @@ static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) INIT_LIST_HEAD(&cfs_rq->throttled_list); } -/* requires cfs_b->lock, may release to reprogram timer */ -void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force) +void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) { - /* - * The timer may be active because we're trying to set a new bandwidth - * period or because we're racing with the tear-down path - * (timer_active==0 becomes visible before the hrtimer call-back - * terminates). In either case we ensure that it's re-programmed - */ - while (unlikely(hrtimer_active(&cfs_b->period_timer)) && - hrtimer_try_to_cancel(&cfs_b->period_timer) < 0) { - /* bounce the lock to allow do_sched_cfs_period_timer to run */ - raw_spin_unlock(&cfs_b->lock); - cpu_relax(); - raw_spin_lock(&cfs_b->lock); - /* if someone else restarted the timer then we're done */ - if (!force && cfs_b->timer_active) - return; - } + lockdep_assert_held(&cfs_b->lock); - cfs_b->timer_active = 1; - start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); + if (!cfs_b->period_active) { + cfs_b->period_active = 1; + hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); + hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED); + } } static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 575da76..e43da53 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -18,19 +18,22 @@ static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) { struct rt_bandwidth *rt_b = container_of(timer, struct rt_bandwidth, rt_period_timer); - ktime_t now; - int overrun; int idle = 0; + int overrun; + raw_spin_lock(&rt_b->rt_runtime_lock); for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, rt_b->rt_period); - + overrun = hrtimer_forward_now(timer, rt_b->rt_period); if (!overrun) break; + raw_spin_unlock(&rt_b->rt_runtime_lock); idle = do_sched_rt_period_timer(rt_b, overrun); + raw_spin_lock(&rt_b->rt_runtime_lock); } + if (idle) + rt_b->rt_period_active = 0; + raw_spin_unlock(&rt_b->rt_runtime_lock); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; } @@ -52,11 +55,12 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b) if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) return; - if (hrtimer_active(&rt_b->rt_period_timer)) - return; - raw_spin_lock(&rt_b->rt_runtime_lock); - start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); + if (!rt_b->rt_period_active) { + rt_b->rt_period_active = 1; + hrtimer_forward_now(&rt_b->rt_period_timer, rt_b->rt_period); + hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED); + } raw_spin_unlock(&rt_b->rt_runtime_lock); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e0e1299..f9a58ef 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -131,6 +131,7 @@ struct rt_bandwidth { ktime_t rt_period; u64 rt_runtime; struct hrtimer rt_period_timer; + unsigned int rt_period_active; }; void __dl_clear_params(struct task_struct *p); @@ -215,7 +216,7 @@ struct cfs_bandwidth { s64 hierarchical_quota; u64 runtime_expires; - int idle, timer_active; + int idle, period_active; struct hrtimer period_timer, slack_timer; struct list_head throttled_cfs_rq; @@ -306,7 +307,7 @@ extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); -extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force); +extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); extern void free_rt_sched_group(struct task_group *tg); @@ -1406,8 +1407,6 @@ static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } static inline void sched_avg_update(struct rq *rq) { } #endif -extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period); - /* * __task_rq_lock - lock the rq @p resides on. */ diff --git a/kernel/time/Makefile b/kernel/time/Makefile index 01f0312..ffc4cc3 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -13,19 +13,4 @@ obj-$(CONFIG_TIMER_STATS) += timer_stats.o obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o obj-$(CONFIG_TEST_UDELAY) += test_udelay.o -$(obj)/time.o: $(obj)/timeconst.h - -quiet_cmd_hzfile = HZFILE $@ - cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@ - -targets += hz.bc -$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE - $(call if_changed,hzfile) - -quiet_cmd_bc = BC $@ - cmd_bc = bc -q $(filter-out FORCE,$^) > $@ - -targets += timeconst.h -$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE - $(call if_changed,bc) - +$(obj)/time.o: $(objtree)/include/config/ diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 1b001ed..7fbba63 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -317,19 +317,16 @@ EXPORT_SYMBOL_GPL(alarm_init); * @alarm: ptr to alarm to set * @start: time to run the alarm */ -int alarm_start(struct alarm *alarm, ktime_t start) +void alarm_start(struct alarm *alarm, ktime_t start) { struct alarm_base *base = &alarm_bases[alarm->type]; unsigned long flags; - int ret; spin_lock_irqsave(&base->lock, flags); alarm->node.expires = start; alarmtimer_enqueue(base, alarm); - ret = hrtimer_start(&alarm->timer, alarm->node.expires, - HRTIMER_MODE_ABS); + hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); spin_unlock_irqrestore(&base->lock, flags); - return ret; } EXPORT_SYMBOL_GPL(alarm_start); @@ -338,12 +335,12 @@ EXPORT_SYMBOL_GPL(alarm_start); * @alarm: ptr to alarm to set * @start: time relative to now to run the alarm */ -int alarm_start_relative(struct alarm *alarm, ktime_t start) +void alarm_start_relative(struct alarm *alarm, ktime_t start) { struct alarm_base *base = &alarm_bases[alarm->type]; start = ktime_add(start, base->gettime()); - return alarm_start(alarm, start); + alarm_start(alarm, start); } EXPORT_SYMBOL_GPL(alarm_start_relative); @@ -495,12 +492,12 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, */ static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) { - clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; - if (!alarmtimer_get_rtcdev()) return -EINVAL; - return hrtimer_get_res(baseid, tp); + tp->tv_sec = 0; + tp->tv_nsec = hrtimer_resolution; + return 0; } /** diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 76d4bd9..4adf320 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -66,7 +66,6 @@ */ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = { - .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), .clock_base = { @@ -74,25 +73,21 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = .index = HRTIMER_BASE_MONOTONIC, .clockid = CLOCK_MONOTONIC, .get_time = &ktime_get, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_REALTIME, .clockid = CLOCK_REALTIME, .get_time = &ktime_get_real, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_BOOTTIME, .clockid = CLOCK_BOOTTIME, .get_time = &ktime_get_boottime, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_TAI, .clockid = CLOCK_TAI, .get_time = &ktime_get_clocktai, - .resolution = KTIME_LOW_RES, }, } }; @@ -109,27 +104,6 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id) return hrtimer_clock_to_base_table[clock_id]; } - -/* - * Get the coarse grained time at the softirq based on xtime and - * wall_to_monotonic. - */ -static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) -{ - ktime_t xtim, mono, boot, tai; - ktime_t off_real, off_boot, off_tai; - - mono = ktime_get_update_offsets_tick(&off_real, &off_boot, &off_tai); - boot = ktime_add(mono, off_boot); - xtim = ktime_add(mono, off_real); - tai = ktime_add(mono, off_tai); - - base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim; - base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono; - base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot; - base->clock_base[HRTIMER_BASE_TAI].softirq_time = tai; -} - /* * Functions and macros which are different for UP/SMP systems are kept in a * single place @@ -441,24 +415,35 @@ static inline void debug_deactivate(struct hrtimer *timer) } #if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS) +static inline void hrtimer_update_next_timer(struct hrtimer_cpu_base *cpu_base, + struct hrtimer *timer) +{ +#ifdef CONFIG_HIGH_RES_TIMERS + cpu_base->next_timer = timer; +#endif +} + static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base) { struct hrtimer_clock_base *base = cpu_base->clock_base; ktime_t expires, expires_next = { .tv64 = KTIME_MAX }; - int i; + unsigned int active = cpu_base->active_bases; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { + hrtimer_update_next_timer(cpu_base, NULL); + for (; active; base++, active >>= 1) { struct timerqueue_node *next; struct hrtimer *timer; - next = timerqueue_getnext(&base->active); - if (!next) + if (!(active & 0x01)) continue; + next = timerqueue_getnext(&base->active); timer = container_of(next, struct hrtimer, node); expires = ktime_sub(hrtimer_get_expires(timer), base->offset); - if (expires.tv64 < expires_next.tv64) + if (expires.tv64 < expires_next.tv64) { expires_next = expires; + hrtimer_update_next_timer(cpu_base, timer); + } } /* * clock_was_set() might have changed base->offset of any of @@ -471,6 +456,16 @@ static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base) } #endif +static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) +{ + ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; + ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; + ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; + + return ktime_get_update_offsets_now(&base->clock_was_set_seq, + offs_real, offs_boot, offs_tai); +} + /* High resolution timer related functions */ #ifdef CONFIG_HIGH_RES_TIMERS @@ -478,6 +473,8 @@ static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base) * High resolution timer enabled ? */ static int hrtimer_hres_enabled __read_mostly = 1; +unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC; +EXPORT_SYMBOL_GPL(hrtimer_resolution); /* * Enable / Disable high resolution mode @@ -506,9 +503,14 @@ static inline int hrtimer_is_hres_enabled(void) /* * Is the high resolution mode active ? */ +static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base) +{ + return cpu_base->hres_active; +} + static inline int hrtimer_hres_active(void) { - return __this_cpu_read(hrtimer_bases.hres_active); + return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases)); } /* @@ -519,7 +521,12 @@ static inline int hrtimer_hres_active(void) static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) { - ktime_t expires_next = __hrtimer_get_next_event(cpu_base); + ktime_t expires_next; + + if (!cpu_base->hres_active) + return; + + expires_next = __hrtimer_get_next_event(cpu_base); if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64) return; @@ -548,58 +555,49 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) } /* - * Shared reprogramming for clock_realtime and clock_monotonic - * * When a timer is enqueued and expires earlier than the already enqueued * timers, we have to check, whether it expires earlier than the timer for * which the clock event device was armed. * - * Note, that in case the state has HRTIMER_STATE_CALLBACK set, no reprogramming - * and no expiry check happens. The timer gets enqueued into the rbtree. The - * reprogramming and expiry check is done in the hrtimer_interrupt or in the - * softirq. - * * Called with interrupts disabled and base->cpu_base.lock held */ -static int hrtimer_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base) +static void hrtimer_reprogram(struct hrtimer *timer, + struct hrtimer_clock_base *base) { struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); - int res; WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); /* - * When the callback is running, we do not reprogram the clock event - * device. The timer callback is either running on a different CPU or - * the callback is executed in the hrtimer_interrupt context. The - * reprogramming is handled either by the softirq, which called the - * callback or at the end of the hrtimer_interrupt. + * If the timer is not on the current cpu, we cannot reprogram + * the other cpus clock event device. */ - if (hrtimer_callback_running(timer)) - return 0; + if (base->cpu_base != cpu_base) + return; + + /* + * If the hrtimer interrupt is running, then it will + * reevaluate the clock bases and reprogram the clock event + * device. The callbacks are always executed in hard interrupt + * context so we don't need an extra check for a running + * callback. + */ + if (cpu_base->in_hrtirq) + return; /* * CLOCK_REALTIME timer might be requested with an absolute - * expiry time which is less than base->offset. Nothing wrong - * about that, just avoid to call into the tick code, which - * has now objections against negative expiry values. + * expiry time which is less than base->offset. Set it to 0. */ if (expires.tv64 < 0) - return -ETIME; + expires.tv64 = 0; if (expires.tv64 >= cpu_base->expires_next.tv64) - return 0; + return; - /* - * When the target cpu of the timer is currently executing - * hrtimer_interrupt(), then we do not touch the clock event - * device. hrtimer_interrupt() will reevaluate all clock bases - * before reprogramming the device. - */ - if (cpu_base->in_hrtirq) - return 0; + /* Update the pointer to the next expiring timer */ + cpu_base->next_timer = timer; /* * If a hang was detected in the last timer interrupt then we @@ -608,15 +606,14 @@ static int hrtimer_reprogram(struct hrtimer *timer, * to make progress. */ if (cpu_base->hang_detected) - return 0; + return; /* - * Clockevents returns -ETIME, when the event was in the past. + * Program the timer hardware. We enforce the expiry for + * events which are already in the past. */ - res = tick_program_event(expires, 0); - if (!IS_ERR_VALUE(res)) - cpu_base->expires_next = expires; - return res; + cpu_base->expires_next = expires; + tick_program_event(expires, 1); } /* @@ -628,15 +625,6 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) base->hres_active = 0; } -static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) -{ - ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; - ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; - ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; - - return ktime_get_update_offsets_now(offs_real, offs_boot, offs_tai); -} - /* * Retrigger next event is called after clock was set * @@ -646,7 +634,7 @@ static void retrigger_next_event(void *arg) { struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); - if (!hrtimer_hres_active()) + if (!base->hres_active) return; raw_spin_lock(&base->lock); @@ -660,29 +648,19 @@ static void retrigger_next_event(void *arg) */ static int hrtimer_switch_to_hres(void) { - int i, cpu = smp_processor_id(); - struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); - unsigned long flags; - - if (base->hres_active) - return 1; - - local_irq_save(flags); + struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); if (tick_init_highres()) { - local_irq_restore(flags); printk(KERN_WARNING "Could not switch to high resolution " - "mode on CPU %d\n", cpu); + "mode on CPU %d\n", base->cpu); return 0; } base->hres_active = 1; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) - base->clock_base[i].resolution = KTIME_HIGH_RES; + hrtimer_resolution = HIGH_RES_NSEC; tick_setup_sched_timer(); /* "Retrigger" the interrupt to get things going */ retrigger_next_event(NULL); - local_irq_restore(flags); return 1; } @@ -704,6 +682,7 @@ void clock_was_set_delayed(void) #else +static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *b) { return 0; } static inline int hrtimer_hres_active(void) { return 0; } static inline int hrtimer_is_hres_enabled(void) { return 0; } static inline int hrtimer_switch_to_hres(void) { return 0; } @@ -801,6 +780,14 @@ void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) * * Forward the timer expiry so it will expire in the future. * Returns the number of overruns. + * + * Can be safely called from the callback function of @timer. If + * called from other contexts @timer must neither be enqueued nor + * running the callback and the caller needs to take care of + * serialization. + * + * Note: This only updates the timer expiry value and does not requeue + * the timer. */ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) { @@ -812,8 +799,11 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) if (delta.tv64 < 0) return 0; - if (interval.tv64 < timer->base->resolution.tv64) - interval.tv64 = timer->base->resolution.tv64; + if (WARN_ON(timer->state & HRTIMER_STATE_ENQUEUED)) + return 0; + + if (interval.tv64 < hrtimer_resolution) + interval.tv64 = hrtimer_resolution; if (unlikely(delta.tv64 >= interval.tv64)) { s64 incr = ktime_to_ns(interval); @@ -847,7 +837,6 @@ static int enqueue_hrtimer(struct hrtimer *timer, { debug_activate(timer); - timerqueue_add(&base->active, &timer->node); base->cpu_base->active_bases |= 1 << base->index; /* @@ -856,7 +845,7 @@ static int enqueue_hrtimer(struct hrtimer *timer, */ timer->state |= HRTIMER_STATE_ENQUEUED; - return (&timer->node == base->active.next); + return timerqueue_add(&base->active, &timer->node); } /* @@ -873,29 +862,28 @@ static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, unsigned long newstate, int reprogram) { - struct timerqueue_node *next_timer; - if (!(timer->state & HRTIMER_STATE_ENQUEUED)) - goto out; + struct hrtimer_cpu_base *cpu_base = base->cpu_base; + unsigned int state = timer->state; + + timer->state = newstate; + if (!(state & HRTIMER_STATE_ENQUEUED)) + return; + + if (!timerqueue_del(&base->active, &timer->node)) + cpu_base->active_bases &= ~(1 << base->index); - next_timer = timerqueue_getnext(&base->active); - timerqueue_del(&base->active, &timer->node); - if (&timer->node == next_timer) { #ifdef CONFIG_HIGH_RES_TIMERS - /* Reprogram the clock event device. if enabled */ - if (reprogram && hrtimer_hres_active()) { - ktime_t expires; - - expires = ktime_sub(hrtimer_get_expires(timer), - base->offset); - if (base->cpu_base->expires_next.tv64 == expires.tv64) - hrtimer_force_reprogram(base->cpu_base, 1); - } + /* + * Note: If reprogram is false we do not update + * cpu_base->next_timer. This happens when we remove the first + * timer on a remote cpu. No harm as we never dereference + * cpu_base->next_timer. So the worst thing what can happen is + * an superflous call to hrtimer_force_reprogram() on the + * remote cpu later on if the same timer gets enqueued again. + */ + if (reprogram && timer == cpu_base->next_timer) + hrtimer_force_reprogram(cpu_base, 1); #endif - } - if (!timerqueue_getnext(&base->active)) - base->cpu_base->active_bases &= ~(1 << base->index); -out: - timer->state = newstate; } /* @@ -931,18 +919,25 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) return 0; } -int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, - unsigned long delta_ns, const enum hrtimer_mode mode, - int wakeup) +/** + * 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 + * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or + * relative (HRTIMER_MODE_REL) + */ +void 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; - int ret, leftmost; + int leftmost; base = lock_hrtimer_base(timer, &flags); /* Remove an active timer from the queue: */ - ret = remove_hrtimer(timer, base); + remove_hrtimer(timer, base); if (mode & HRTIMER_MODE_REL) { tim = ktime_add_safe(tim, base->get_time()); @@ -954,7 +949,7 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, * timeouts. This will go away with the GTOD framework. */ #ifdef CONFIG_TIME_LOW_RES - tim = ktime_add_safe(tim, base->resolution); + tim = ktime_add_safe(tim, ktime_set(0, hrtimer_resolution)); #endif } @@ -966,11 +961,8 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, timer_stats_hrtimer_set_start_info(timer); leftmost = enqueue_hrtimer(timer, new_base); - - if (!leftmost) { - unlock_hrtimer_base(timer, &flags); - return ret; - } + if (!leftmost) + goto unlock; if (!hrtimer_is_hres_active(timer)) { /* @@ -978,73 +970,15 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, * on dynticks target. */ wake_up_nohz_cpu(new_base->cpu_base->cpu); - } else if (new_base->cpu_base == this_cpu_ptr(&hrtimer_bases) && - hrtimer_reprogram(timer, new_base)) { - /* - * Only allow reprogramming if the new base is on this CPU. - * (it might still be on another CPU if the timer was pending) - * - * XXX send_remote_softirq() ? - */ - if (wakeup) { - /* - * We need to drop cpu_base->lock to avoid a - * lock ordering issue vs. rq->lock. - */ - raw_spin_unlock(&new_base->cpu_base->lock); - raise_softirq_irqoff(HRTIMER_SOFTIRQ); - local_irq_restore(flags); - return ret; - } else { - __raise_softirq_irqoff(HRTIMER_SOFTIRQ); - } + } else { + hrtimer_reprogram(timer, new_base); } - +unlock: unlock_hrtimer_base(timer, &flags); - - return ret; -} -EXPORT_SYMBOL_GPL(__hrtimer_start_range_ns); - -/** - * 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 - * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or - * relative (HRTIMER_MODE_REL) - * - * Returns: - * 0 on success - * 1 when the timer was active - */ -int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, - unsigned long delta_ns, const enum hrtimer_mode mode) -{ - return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1); } EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); /** - * hrtimer_start - (re)start an hrtimer on the current CPU - * @timer: the timer to be added - * @tim: expiry time - * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or - * relative (HRTIMER_MODE_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, 1); -} -EXPORT_SYMBOL_GPL(hrtimer_start); - - -/** * hrtimer_try_to_cancel - try to deactivate a timer * @timer: hrtimer to stop * @@ -1060,6 +994,15 @@ int hrtimer_try_to_cancel(struct hrtimer *timer) unsigned long flags; int ret = -1; + /* + * Check lockless first. If the timer is not active (neither + * enqueued nor running the callback, nothing to do here. The + * base lock does not serialize against a concurrent enqueue, + * so we can avoid taking it. + */ + if (!hrtimer_active(timer)) + return 0; + base = lock_hrtimer_base(timer, &flags); if (!hrtimer_callback_running(timer)) @@ -1113,26 +1056,22 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining); /** * hrtimer_get_next_event - get the time until next expiry event * - * Returns the delta to the next expiry event or KTIME_MAX if no timer - * is pending. + * Returns the next expiry time or KTIME_MAX if no timer is pending. */ -ktime_t hrtimer_get_next_event(void) +u64 hrtimer_get_next_event(void) { struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); - ktime_t mindelta = { .tv64 = KTIME_MAX }; + u64 expires = KTIME_MAX; unsigned long flags; raw_spin_lock_irqsave(&cpu_base->lock, flags); - if (!hrtimer_hres_active()) - mindelta = ktime_sub(__hrtimer_get_next_event(cpu_base), - ktime_get()); + if (!__hrtimer_hres_active(cpu_base)) + expires = __hrtimer_get_next_event(cpu_base).tv64; raw_spin_unlock_irqrestore(&cpu_base->lock, flags); - if (mindelta.tv64 < 0) - mindelta.tv64 = 0; - return mindelta; + return expires; } #endif @@ -1174,30 +1113,10 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, } EXPORT_SYMBOL_GPL(hrtimer_init); -/** - * hrtimer_get_res - get the timer resolution for a clock - * @which_clock: which clock to query - * @tp: pointer to timespec variable to store the resolution - * - * Store the resolution of the clock selected by @which_clock in the - * variable pointed to by @tp. - */ -int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) -{ - struct hrtimer_cpu_base *cpu_base; - int base = hrtimer_clockid_to_base(which_clock); - - cpu_base = raw_cpu_ptr(&hrtimer_bases); - *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution); - - return 0; -} -EXPORT_SYMBOL_GPL(hrtimer_get_res); - -static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) +static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, + struct hrtimer_clock_base *base, + struct hrtimer *timer, ktime_t *now) { - struct hrtimer_clock_base *base = timer->base; - struct hrtimer_cpu_base *cpu_base = base->cpu_base; enum hrtimer_restart (*fn)(struct hrtimer *); int restart; @@ -1223,55 +1142,32 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) * Note: We clear the CALLBACK bit after enqueue_hrtimer and * we do not reprogramm the event hardware. Happens either in * hrtimer_start_range_ns() or in hrtimer_interrupt() + * + * Note: Because we dropped the cpu_base->lock above, + * hrtimer_start_range_ns() can have popped in and enqueued the timer + * for us already. */ - if (restart != HRTIMER_NORESTART) { - BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); + if (restart != HRTIMER_NORESTART && + !(timer->state & HRTIMER_STATE_ENQUEUED)) enqueue_hrtimer(timer, base); - } WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK)); timer->state &= ~HRTIMER_STATE_CALLBACK; } -#ifdef CONFIG_HIGH_RES_TIMERS - -/* - * High resolution timer interrupt - * Called with interrupts disabled - */ -void hrtimer_interrupt(struct clock_event_device *dev) +static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) { - struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); - ktime_t expires_next, now, entry_time, delta; - int i, retries = 0; - - BUG_ON(!cpu_base->hres_active); - cpu_base->nr_events++; - dev->next_event.tv64 = KTIME_MAX; - - raw_spin_lock(&cpu_base->lock); - entry_time = now = hrtimer_update_base(cpu_base); -retry: - cpu_base->in_hrtirq = 1; - /* - * We set expires_next to KTIME_MAX here with cpu_base->lock - * held to prevent that a timer is enqueued in our queue via - * the migration code. This does not affect enqueueing of - * timers which run their callback and need to be requeued on - * this CPU. - */ - cpu_base->expires_next.tv64 = KTIME_MAX; + struct hrtimer_clock_base *base = cpu_base->clock_base; + unsigned int active = cpu_base->active_bases; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - struct hrtimer_clock_base *base; + for (; active; base++, active >>= 1) { struct timerqueue_node *node; ktime_t basenow; - if (!(cpu_base->active_bases & (1 << i))) + if (!(active & 0x01)) continue; - base = cpu_base->clock_base + i; basenow = ktime_add(now, base->offset); while ((node = timerqueue_getnext(&base->active))) { @@ -1294,9 +1190,42 @@ retry: if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) break; - __run_hrtimer(timer, &basenow); + __run_hrtimer(cpu_base, base, timer, &basenow); } } +} + +#ifdef CONFIG_HIGH_RES_TIMERS + +/* + * High resolution timer interrupt + * Called with interrupts disabled + */ +void hrtimer_interrupt(struct clock_event_device *dev) +{ + struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); + ktime_t expires_next, now, entry_time, delta; + int retries = 0; + + BUG_ON(!cpu_base->hres_active); + cpu_base->nr_events++; + dev->next_event.tv64 = KTIME_MAX; + + raw_spin_lock(&cpu_base->lock); + entry_time = now = hrtimer_update_base(cpu_base); +retry: + cpu_base->in_hrtirq = 1; + /* + * We set expires_next to KTIME_MAX here with cpu_base->lock + * held to prevent that a timer is enqueued in our queue via + * the migration code. This does not affect enqueueing of + * timers which run their callback and need to be requeued on + * this CPU. + */ + cpu_base->expires_next.tv64 = KTIME_MAX; + + __hrtimer_run_queues(cpu_base, now); + /* Reevaluate the clock bases for the next expiry */ expires_next = __hrtimer_get_next_event(cpu_base); /* @@ -1342,8 +1271,8 @@ retry: cpu_base->hang_detected = 1; raw_spin_unlock(&cpu_base->lock); delta = ktime_sub(now, entry_time); - if (delta.tv64 > cpu_base->max_hang_time.tv64) - cpu_base->max_hang_time = delta; + if ((unsigned int)delta.tv64 > cpu_base->max_hang_time) + cpu_base->max_hang_time = (unsigned int) delta.tv64; /* * Limit it to a sensible value as we enforce a longer * delay. Give the CPU at least 100ms to catch up. @@ -1361,7 +1290,7 @@ retry: * local version of hrtimer_peek_ahead_timers() called with interrupts * disabled. */ -static void __hrtimer_peek_ahead_timers(void) +static inline void __hrtimer_peek_ahead_timers(void) { struct tick_device *td; @@ -1373,29 +1302,6 @@ static void __hrtimer_peek_ahead_timers(void) hrtimer_interrupt(td->evtdev); } -/** - * 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; - - local_irq_save(flags); - __hrtimer_peek_ahead_timers(); - local_irq_restore(flags); -} - -static void run_hrtimer_softirq(struct softirq_action *h) -{ - hrtimer_peek_ahead_timers(); -} - #else /* CONFIG_HIGH_RES_TIMERS */ static inline void __hrtimer_peek_ahead_timers(void) { } @@ -1403,66 +1309,32 @@ static inline void __hrtimer_peek_ahead_timers(void) { } #endif /* !CONFIG_HIGH_RES_TIMERS */ /* - * Called from timer softirq every jiffy, expire hrtimers: - * - * For HRT its the fall back code to run the softirq in the timer - * softirq context in case the hrtimer initialization failed or has - * not been done yet. + * Called from run_local_timers in hardirq context every jiffy */ -void hrtimer_run_pending(void) +void hrtimer_run_queues(void) { - if (hrtimer_hres_active()) + struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); + ktime_t now; + + if (__hrtimer_hres_active(cpu_base)) return; /* - * This _is_ ugly: We have to check in the softirq context, - * whether we can switch to highres and / or nohz mode. The - * clocksource switch happens in the timer interrupt with - * xtime_lock held. Notification from there only sets the - * check bit in the tick_oneshot code, otherwise we might - * deadlock vs. xtime_lock. + * This _is_ ugly: We have to check periodically, whether we + * can switch to highres and / or nohz mode. The clocksource + * switch happens with xtime_lock held. Notification from + * there only sets the check bit in the tick_oneshot code, + * otherwise we might deadlock vs. xtime_lock. */ - if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) + if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) { hrtimer_switch_to_hres(); -} - -/* - * Called from hardirq context every jiffy - */ -void hrtimer_run_queues(void) -{ - struct timerqueue_node *node; - struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); - struct hrtimer_clock_base *base; - int index, gettime = 1; - - if (hrtimer_hres_active()) return; - - for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { - base = &cpu_base->clock_base[index]; - if (!timerqueue_getnext(&base->active)) - continue; - - if (gettime) { - hrtimer_get_softirq_time(cpu_base); - gettime = 0; - } - - raw_spin_lock(&cpu_base->lock); - - while ((node = timerqueue_getnext(&base->active))) { - struct hrtimer *timer; - - timer = container_of(node, struct hrtimer, node); - if (base->softirq_time.tv64 <= - hrtimer_get_expires_tv64(timer)) - break; - - __run_hrtimer(timer, &base->softirq_time); - } - raw_spin_unlock(&cpu_base->lock); } + + raw_spin_lock(&cpu_base->lock); + now = hrtimer_update_base(cpu_base); + __hrtimer_run_queues(cpu_base, now); + raw_spin_unlock(&cpu_base->lock); } /* @@ -1495,8 +1367,6 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod do { set_current_state(TASK_INTERRUPTIBLE); hrtimer_start_expires(&t->timer, mode); - if (!hrtimer_active(&t->timer)) - t->task = NULL; if (likely(t->task)) freezable_schedule(); @@ -1729,9 +1599,6 @@ void __init hrtimers_init(void) hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); register_cpu_notifier(&hrtimers_nb); -#ifdef CONFIG_HIGH_RES_TIMERS - open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); -#endif } /** @@ -1770,8 +1637,6 @@ schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta, hrtimer_init_sleeper(&t, current); hrtimer_start_expires(&t.timer, mode); - if (!hrtimer_active(&t.timer)) - t.task = NULL; if (likely(t.task)) schedule(); diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 31ea01f..31d11ac 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -272,13 +272,20 @@ static int posix_get_tai(clockid_t which_clock, struct timespec *tp) return 0; } +static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec *tp) +{ + tp->tv_sec = 0; + tp->tv_nsec = hrtimer_resolution; + return 0; +} + /* * Initialize everything, well, just everything in Posix clocks/timers ;) */ static __init int init_posix_timers(void) { struct k_clock clock_realtime = { - .clock_getres = hrtimer_get_res, + .clock_getres = posix_get_hrtimer_res, .clock_get = posix_clock_realtime_get, .clock_set = posix_clock_realtime_set, .clock_adj = posix_clock_realtime_adj, @@ -290,7 +297,7 @@ static __init int init_posix_timers(void) .timer_del = common_timer_del, }; struct k_clock clock_monotonic = { - .clock_getres = hrtimer_get_res, + .clock_getres = posix_get_hrtimer_res, .clock_get = posix_ktime_get_ts, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, @@ -300,7 +307,7 @@ static __init int init_posix_timers(void) .timer_del = common_timer_del, }; struct k_clock clock_monotonic_raw = { - .clock_getres = hrtimer_get_res, + .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_monotonic_raw, }; struct k_clock clock_realtime_coarse = { @@ -312,7 +319,7 @@ static __init int init_posix_timers(void) .clock_get = posix_get_monotonic_coarse, }; struct k_clock clock_tai = { - .clock_getres = hrtimer_get_res, + .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_tai, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, @@ -322,7 +329,7 @@ static __init int init_posix_timers(void) .timer_del = common_timer_del, }; struct k_clock clock_boottime = { - .clock_getres = hrtimer_get_res, + .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_boottime, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c index 6aac4be..3e7db49 100644 --- a/kernel/time/tick-broadcast-hrtimer.c +++ b/kernel/time/tick-broadcast-hrtimer.c @@ -22,6 +22,7 @@ static void bc_set_mode(enum clock_event_mode mode, struct clock_event_device *bc) { switch (mode) { + case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: /* * Note, we cannot cancel the timer here as we might @@ -66,9 +67,11 @@ static int bc_set_next(ktime_t expires, struct clock_event_device *bc) * hrtimer_{start/cancel} functions call into tracing, * calls to these functions must be bound within RCU_NONIDLE. */ - RCU_NONIDLE(bc_moved = (hrtimer_try_to_cancel(&bctimer) >= 0) ? - !hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED) : - 0); + RCU_NONIDLE({ + bc_moved = hrtimer_try_to_cancel(&bctimer) >= 0; + if (bc_moved) + hrtimer_start(&bctimer, expires, + HRTIMER_MODE_ABS_PINNED);}); if (bc_moved) { /* Bind the "device" to the cpu */ bc->bound_on = smp_processor_id(); @@ -99,10 +102,13 @@ static enum hrtimer_restart bc_handler(struct hrtimer *t) { ce_broadcast_hrtimer.event_handler(&ce_broadcast_hrtimer); - if (ce_broadcast_hrtimer.next_event.tv64 == KTIME_MAX) + switch (ce_broadcast_hrtimer.mode) { + case CLOCK_EVT_MODE_ONESHOT: + if (ce_broadcast_hrtimer.next_event.tv64 != KTIME_MAX) + return HRTIMER_RESTART; + default: return HRTIMER_NORESTART; - - return HRTIMER_RESTART; + } } void tick_setup_hrtimer_broadcast(void) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 7e8ca4f..12fcc55 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -255,18 +255,18 @@ int tick_receive_broadcast(void) /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ -static void tick_do_broadcast(struct cpumask *mask) +static bool tick_do_broadcast(struct cpumask *mask) { int cpu = smp_processor_id(); struct tick_device *td; + bool local = false; /* * Check, if the current cpu is in the mask */ if (cpumask_test_cpu(cpu, mask)) { cpumask_clear_cpu(cpu, mask); - td = &per_cpu(tick_cpu_device, cpu); - td->evtdev->event_handler(td->evtdev); + local = true; } if (!cpumask_empty(mask)) { @@ -279,16 +279,17 @@ static void tick_do_broadcast(struct cpumask *mask) td = &per_cpu(tick_cpu_device, cpumask_first(mask)); td->evtdev->broadcast(mask); } + return local; } /* * Periodic broadcast: * - invoke the broadcast handlers */ -static void tick_do_periodic_broadcast(void) +static bool tick_do_periodic_broadcast(void) { cpumask_and(tmpmask, cpu_online_mask, tick_broadcast_mask); - tick_do_broadcast(tmpmask); + return tick_do_broadcast(tmpmask); } /* @@ -296,34 +297,26 @@ static void tick_do_periodic_broadcast(void) */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { - ktime_t next; + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + bool bc_local; raw_spin_lock(&tick_broadcast_lock); + bc_local = tick_do_periodic_broadcast(); - tick_do_periodic_broadcast(); + if (dev->state == CLOCK_EVT_STATE_ONESHOT) { + ktime_t next = ktime_add(dev->next_event, tick_period); - /* - * The device is in periodic mode. No reprogramming necessary: - */ - if (dev->state == CLOCK_EVT_STATE_PERIODIC) - goto unlock; + clockevents_program_event(dev, next, true); + } + raw_spin_unlock(&tick_broadcast_lock); /* - * Setup the next period for devices, which do not have - * periodic mode. We read dev->next_event first and add to it - * when the event already expired. clockevents_program_event() - * sets dev->next_event only when the event is really - * programmed to the device. + * We run the handler of the local cpu after dropping + * tick_broadcast_lock because the handler might deadlock when + * trying to switch to oneshot mode. */ - for (next = dev->next_event; ;) { - next = ktime_add(next, tick_period); - - if (!clockevents_program_event(dev, next, false)) - goto unlock; - tick_do_periodic_broadcast(); - } -unlock: - raw_spin_unlock(&tick_broadcast_lock); + if (bc_local) + td->evtdev->event_handler(td->evtdev); } /** @@ -532,18 +525,14 @@ static void tick_broadcast_set_affinity(struct clock_event_device *bc, irq_set_affinity(bc->irq, bc->cpumask); } -static int tick_broadcast_set_event(struct clock_event_device *bc, int cpu, - ktime_t expires, int force) +static void tick_broadcast_set_event(struct clock_event_device *bc, int cpu, + ktime_t expires) { - int ret; - if (bc->state != CLOCK_EVT_STATE_ONESHOT) clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT); - ret = clockevents_program_event(bc, expires, force); - if (!ret) - tick_broadcast_set_affinity(bc, cpumask_of(cpu)); - return ret; + clockevents_program_event(bc, expires, 1); + tick_broadcast_set_affinity(bc, cpumask_of(cpu)); } static void tick_resume_broadcast_oneshot(struct clock_event_device *bc) @@ -580,9 +569,9 @@ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev) struct tick_device *td; ktime_t now, next_event; int cpu, next_cpu = 0; + bool bc_local; raw_spin_lock(&tick_broadcast_lock); -again: dev->next_event.tv64 = KTIME_MAX; next_event.tv64 = KTIME_MAX; cpumask_clear(tmpmask); @@ -624,7 +613,7 @@ again: /* * Wakeup the cpus which have an expired event. */ - tick_do_broadcast(tmpmask); + bc_local = tick_do_broadcast(tmpmask); /* * Two reasons for reprogram: @@ -636,15 +625,15 @@ again: * - There are pending events on sleeping CPUs which were not * in the event mask */ - if (next_event.tv64 != KTIME_MAX) { - /* - * Rearm the broadcast device. If event expired, - * repeat the above - */ - if (tick_broadcast_set_event(dev, next_cpu, next_event, 0)) - goto again; - } + if (next_event.tv64 != KTIME_MAX) + tick_broadcast_set_event(dev, next_cpu, next_event); + raw_spin_unlock(&tick_broadcast_lock); + + if (bc_local) { + td = this_cpu_ptr(&tick_cpu_device); + td->evtdev->event_handler(td->evtdev); + } } static int broadcast_needs_cpu(struct clock_event_device *bc, int cpu) @@ -726,7 +715,7 @@ int tick_broadcast_oneshot_control(enum tick_broadcast_state state) */ if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) && dev->next_event.tv64 < bc->next_event.tv64) - tick_broadcast_set_event(bc, cpu, dev->next_event, 1); + tick_broadcast_set_event(bc, cpu, dev->next_event); } /* * If the current CPU owns the hrtimer broadcast @@ -861,7 +850,7 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT); tick_broadcast_init_next_event(tmpmask, tick_next_period); - tick_broadcast_set_event(bc, cpu, tick_next_period, 1); + tick_broadcast_set_event(bc, cpu, tick_next_period); } else bc->next_event.tv64 = KTIME_MAX; } else { diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 3ae6afa..ea5f9ea 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -102,6 +102,16 @@ void tick_handle_periodic(struct clock_event_device *dev) tick_periodic(cpu); +#if defined(CONFIG_HIGH_RES_TIMERS) || defined(CONFIG_NO_HZ_COMMON) + /* + * The cpu might have transitioned to HIGHRES or NOHZ mode via + * update_process_times() -> run_local_timers() -> + * hrtimer_run_queues(). + */ + if (dev->event_handler != tick_handle_periodic) + return; +#endif + if (dev->state != CLOCK_EVT_STATE_ONESHOT) return; for (;;) { diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index b64fdd8..65273f0 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -137,3 +137,5 @@ extern void tick_nohz_init(void); # else static inline void tick_nohz_init(void) { } #endif + +extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9142591..812f7a3 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -565,156 +565,144 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time) } EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us); +static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) +{ + hrtimer_cancel(&ts->sched_timer); + hrtimer_set_expires(&ts->sched_timer, ts->last_tick); + + /* 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_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED); + else + tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1); +} + static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, ktime_t now, int cpu) { - unsigned long seq, last_jiffies, next_jiffies, delta_jiffies; - ktime_t last_update, expires, ret = { .tv64 = 0 }; - unsigned long rcu_delta_jiffies; struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); - u64 time_delta; - - time_delta = timekeeping_max_deferment(); + u64 basemono, next_tick, next_tmr, next_rcu, delta, expires; + unsigned long seq, basejiff; + ktime_t tick; /* Read jiffies and the time when jiffies were updated last */ do { seq = read_seqbegin(&jiffies_lock); - last_update = last_jiffies_update; - last_jiffies = jiffies; + basemono = last_jiffies_update.tv64; + basejiff = jiffies; } while (read_seqretry(&jiffies_lock, seq)); + ts->last_jiffies = basejiff; - if (rcu_needs_cpu(&rcu_delta_jiffies) || + if (rcu_needs_cpu(basemono, &next_rcu) || arch_needs_cpu() || irq_work_needs_cpu()) { - next_jiffies = last_jiffies + 1; - delta_jiffies = 1; + next_tick = basemono + TICK_NSEC; } else { - /* Get the next timer wheel timer */ - next_jiffies = get_next_timer_interrupt(last_jiffies); - delta_jiffies = next_jiffies - last_jiffies; - if (rcu_delta_jiffies < delta_jiffies) { - next_jiffies = last_jiffies + rcu_delta_jiffies; - delta_jiffies = rcu_delta_jiffies; - } + /* + * Get the next pending timer. If high resolution + * timers are enabled this only takes the timer wheel + * timers into account. If high resolution timers are + * disabled this also looks at the next expiring + * hrtimer. + */ + next_tmr = get_next_timer_interrupt(basejiff, basemono); + ts->next_timer = next_tmr; + /* Take the next rcu event into account */ + next_tick = next_rcu < next_tmr ? next_rcu : next_tmr; } /* - * Do not stop the tick, if we are only one off (or less) - * or if the cpu is required for RCU: + * If the tick is due in the next period, keep it ticking or + * restart it proper. */ - if (!ts->tick_stopped && delta_jiffies <= 1) - goto out; - - /* Schedule the tick, if we are at least one jiffie off */ - if ((long)delta_jiffies >= 1) { - - /* - * If this cpu is the one which updates jiffies, then - * give up the assignment and let it be taken by the - * cpu which runs the tick timer next, which might be - * this cpu as well. If we don't drop this here the - * jiffies might be stale and do_timer() never - * invoked. Keep track of the fact that it was the one - * which had the do_timer() duty last. If this cpu is - * the one which had the do_timer() duty last, we - * limit the sleep time to the timekeeping - * max_deferement value which we retrieved - * above. Otherwise we can sleep as long as we want. - */ - if (cpu == tick_do_timer_cpu) { - tick_do_timer_cpu = TICK_DO_TIMER_NONE; - ts->do_timer_last = 1; - } else if (tick_do_timer_cpu != TICK_DO_TIMER_NONE) { - time_delta = KTIME_MAX; - ts->do_timer_last = 0; - } else if (!ts->do_timer_last) { - time_delta = KTIME_MAX; + delta = next_tick - basemono; + if (delta <= (u64)TICK_NSEC) { + tick.tv64 = 0; + if (!ts->tick_stopped) + goto out; + if (delta == 0) { + /* Tick is stopped, but required now. Enforce it */ + tick_nohz_restart(ts, now); + goto out; } + } + + /* + * If this cpu is the one which updates jiffies, then give up + * the assignment and let it be taken by the cpu which runs + * the tick timer next, which might be this cpu as well. If we + * don't drop this here the jiffies might be stale and + * do_timer() never invoked. Keep track of the fact that it + * was the one which had the do_timer() duty last. If this cpu + * is the one which had the do_timer() duty last, we limit the + * sleep time to the timekeeping max_deferement value. + * Otherwise we can sleep as long as we want. + */ + delta = timekeeping_max_deferment(); + if (cpu == tick_do_timer_cpu) { + tick_do_timer_cpu = TICK_DO_TIMER_NONE; + ts->do_timer_last = 1; + } else if (tick_do_timer_cpu != TICK_DO_TIMER_NONE) { + delta = KTIME_MAX; + ts->do_timer_last = 0; + } else if (!ts->do_timer_last) { + delta = KTIME_MAX; + } #ifdef CONFIG_NO_HZ_FULL - if (!ts->inidle) { - time_delta = min(time_delta, - scheduler_tick_max_deferment()); - } + /* Limit the tick delta to the maximum scheduler deferment */ + if (!ts->inidle) + delta = min(delta, scheduler_tick_max_deferment()); #endif - /* - * calculate the expiry time for the next timer wheel - * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals - * that there is no timer pending or at least extremely - * far into the future (12 days for HZ=1000). In this - * case we set the expiry to the end of time. - */ - if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) { - /* - * Calculate the time delta for the next timer event. - * If the time delta exceeds the maximum time delta - * permitted by the current clocksource then adjust - * the time delta accordingly to ensure the - * clocksource does not wrap. - */ - time_delta = min_t(u64, time_delta, - tick_period.tv64 * delta_jiffies); - } - - if (time_delta < KTIME_MAX) - expires = ktime_add_ns(last_update, time_delta); - else - expires.tv64 = KTIME_MAX; - - /* Skip reprogram of event if its not changed */ - if (ts->tick_stopped && ktime_equal(expires, dev->next_event)) - goto out; + /* Calculate the next expiry time */ + if (delta < (KTIME_MAX - basemono)) + expires = basemono + delta; + else + expires = KTIME_MAX; - ret = expires; + expires = min_t(u64, expires, next_tick); + tick.tv64 = expires; - /* - * nohz_stop_sched_tick can be called several times before - * the nohz_restart_sched_tick is called. This happens when - * interrupts arrive which do not cause a reschedule. In the - * first call we save the current tick time, so we can restart - * the scheduler tick in nohz_restart_sched_tick. - */ - if (!ts->tick_stopped) { - nohz_balance_enter_idle(cpu); - calc_load_enter_idle(); + /* Skip reprogram of event if its not changed */ + if (ts->tick_stopped && (expires == dev->next_event.tv64)) + goto out; - ts->last_tick = hrtimer_get_expires(&ts->sched_timer); - ts->tick_stopped = 1; - trace_tick_stop(1, " "); - } + /* + * nohz_stop_sched_tick can be called several times before + * the nohz_restart_sched_tick is called. This happens when + * interrupts arrive which do not cause a reschedule. In the + * first call we save the current tick time, so we can restart + * the scheduler tick in nohz_restart_sched_tick. + */ + if (!ts->tick_stopped) { + nohz_balance_enter_idle(cpu); + calc_load_enter_idle(); - /* - * If the expiration time == KTIME_MAX, then - * in this case we simply stop the tick timer. - */ - if (unlikely(expires.tv64 == KTIME_MAX)) { - if (ts->nohz_mode == NOHZ_MODE_HIGHRES) - hrtimer_cancel(&ts->sched_timer); - goto out; - } + ts->last_tick = hrtimer_get_expires(&ts->sched_timer); + ts->tick_stopped = 1; + trace_tick_stop(1, " "); + } - if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { - hrtimer_start(&ts->sched_timer, expires, - HRTIMER_MODE_ABS_PINNED); - /* Check, if the timer was already in the past */ - if (hrtimer_active(&ts->sched_timer)) - goto out; - } else if (!tick_program_event(expires, 0)) - goto out; - /* - * We are past the event already. So we crossed a - * jiffie boundary. Update jiffies and raise the - * softirq. - */ - tick_do_update_jiffies64(ktime_get()); + /* + * If the expiration time == KTIME_MAX, then we simply stop + * the tick timer. + */ + if (unlikely(expires == KTIME_MAX)) { + if (ts->nohz_mode == NOHZ_MODE_HIGHRES) + hrtimer_cancel(&ts->sched_timer); + goto out; } - raise_softirq_irqoff(TIMER_SOFTIRQ); + + if (ts->nohz_mode == NOHZ_MODE_HIGHRES) + hrtimer_start(&ts->sched_timer, tick, HRTIMER_MODE_ABS_PINNED); + else + tick_program_event(tick, 1); out: - ts->next_jiffies = next_jiffies; - ts->last_jiffies = last_jiffies; + /* Update the estimated sleep length */ ts->sleep_length = ktime_sub(dev->next_event, now); - - return ret; + return tick; } static void tick_nohz_full_stop_tick(struct tick_sched *ts) @@ -876,32 +864,6 @@ 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); - hrtimer_set_expires(&ts->sched_timer, ts->last_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_expires(&ts->sched_timer, - HRTIMER_MODE_ABS_PINNED); - /* Check, if the timer was already in the past */ - if (hrtimer_active(&ts->sched_timer)) - break; - } else { - if (!tick_program_event( - hrtimer_get_expires(&ts->sched_timer), 0)) - break; - } - /* Reread time and update jiffies */ - now = ktime_get(); - tick_do_update_jiffies64(now); - } -} - static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now) { /* Update jiffies first */ @@ -972,12 +934,6 @@ void tick_nohz_idle_exit(void) local_irq_enable(); } -static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now) -{ - hrtimer_forward(&ts->sched_timer, now, tick_period); - return tick_program_event(hrtimer_get_expires(&ts->sched_timer), 0); -} - /* * The nohz low res interrupt handler */ @@ -996,10 +952,8 @@ static void tick_nohz_handler(struct clock_event_device *dev) if (unlikely(ts->tick_stopped)) return; - while (tick_nohz_reprogram(ts, now)) { - now = ktime_get(); - tick_do_update_jiffies64(now); - } + hrtimer_forward(&ts->sched_timer, now, tick_period); + tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1); } /** @@ -1013,11 +967,9 @@ static void tick_nohz_switch_to_nohz(void) if (!tick_nohz_enabled) return; - local_irq_disable(); - if (tick_switch_to_oneshot(tick_nohz_handler)) { - local_irq_enable(); + if (tick_switch_to_oneshot(tick_nohz_handler)) return; - } + tick_nohz_active = 1; ts->nohz_mode = NOHZ_MODE_LOWRES; @@ -1029,13 +981,9 @@ static void tick_nohz_switch_to_nohz(void) /* Get the next period */ next = tick_init_jiffy_update(); - for (;;) { - hrtimer_set_expires(&ts->sched_timer, next); - if (!tick_program_event(next, 0)) - break; - next = ktime_add(next, tick_period); - } - local_irq_enable(); + hrtimer_forward_now(&ts->sched_timer, tick_period); + hrtimer_set_expires(&ts->sched_timer, next); + tick_program_event(next, 1); } /* @@ -1167,15 +1115,8 @@ void tick_setup_sched_timer(void) hrtimer_add_expires_ns(&ts->sched_timer, offset); } - for (;;) { - hrtimer_forward(&ts->sched_timer, now, tick_period); - hrtimer_start_expires(&ts->sched_timer, - HRTIMER_MODE_ABS_PINNED); - /* Check, if the timer was already in the past */ - if (hrtimer_active(&ts->sched_timer)) - break; - now = ktime_get(); - } + hrtimer_forward(&ts->sched_timer, now, tick_period); + hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED); #ifdef CONFIG_NO_HZ_COMMON if (tick_nohz_enabled) { @@ -1227,7 +1168,7 @@ void tick_oneshot_notify(void) * Called cyclic from the hrtimer softirq (driven by the timer * softirq) allow_nohz signals, that we can switch into low-res nohz * mode, because high resolution timers are disabled (either compile - * or runtime). + * or runtime). Called with interrupts disabled. */ int tick_check_oneshot_change(int allow_nohz) { diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index 28b5da3..42fdf49 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -57,7 +57,7 @@ struct tick_sched { ktime_t iowait_sleeptime; ktime_t sleep_length; unsigned long last_jiffies; - unsigned long next_jiffies; + u64 next_timer; ktime_t idle_expires; int do_timer_last; }; diff --git a/kernel/time/time.c b/kernel/time/time.c index 2c85b77..c42c2c3 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -41,7 +41,7 @@ #include <asm/uaccess.h> #include <asm/unistd.h> -#include "timeconst.h" +#include <generated/timeconst.h> #include "timekeeping.h" /* @@ -483,9 +483,11 @@ struct timespec64 ns_to_timespec64(const s64 nsec) } EXPORT_SYMBOL(ns_to_timespec64); #endif -/* - * When we convert to jiffies then we interpret incoming values - * the following way: +/** + * msecs_to_jiffies: - convert milliseconds to jiffies + * @m: time in milliseconds + * + * conversion is done as follows: * * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) * @@ -493,51 +495,28 @@ EXPORT_SYMBOL(ns_to_timespec64); * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. * * - all other values are converted to jiffies by either multiplying - * the input value by a factor or dividing it with a factor - * - * We must also be careful about 32-bit overflows. + * the input value by a factor or dividing it with a factor and + * handling any 32-bit overflows. + * for the details see __msecs_to_jiffies() + * + * msecs_to_jiffies() checks for the passed in value being a constant + * via __builtin_constant_p() allowing gcc to eliminate most of the + * code, __msecs_to_jiffies() is called if the value passed does not + * allow constant folding and the actual conversion must be done at + * runtime. + * the _msecs_to_jiffies helpers are the HZ dependent conversion + * routines found in include/linux/jiffies.h */ -unsigned long msecs_to_jiffies(const unsigned int m) +unsigned long __msecs_to_jiffies(const unsigned int m) { /* * Negative value, means infinite timeout: */ if ((int)m < 0) return MAX_JIFFY_OFFSET; - -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) - /* - * HZ is equal to or smaller than 1000, and 1000 is a nice - * round multiple of HZ, divide with the factor between them, - * but round upwards: - */ - return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) - /* - * HZ is larger than 1000, and HZ is a nice round multiple of - * 1000 - simply multiply with the factor between them. - * - * But first make sure the multiplication result cannot - * overflow: - */ - if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return m * (HZ / MSEC_PER_SEC); -#else - /* - * Generic case - multiply, round and divide. But first - * check that if we are doing a net multiplication, that - * we wouldn't overflow: - */ - if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) - >> MSEC_TO_HZ_SHR32; -#endif + return _msecs_to_jiffies(m); } -EXPORT_SYMBOL(msecs_to_jiffies); +EXPORT_SYMBOL(__msecs_to_jiffies); unsigned long usecs_to_jiffies(const unsigned int u) { diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc index 511bdf2..c7388de 100644 --- a/kernel/time/timeconst.bc +++ b/kernel/time/timeconst.bc @@ -50,7 +50,7 @@ define timeconst(hz) { print "#include <linux/types.h>\n\n" print "#if HZ != ", hz, "\n" - print "#error \qkernel/timeconst.h has the wrong HZ value!\q\n" + print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n" print "#endif\n\n" if (hz < 2) { @@ -105,4 +105,5 @@ define timeconst(hz) { halt } +hz = read(); timeconst(hz) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 946acb7..3365e32 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -602,6 +602,9 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); + + if (action & TK_CLOCK_WAS_SET) + tk->clock_was_set_seq++; } /** @@ -1926,47 +1929,20 @@ void do_timer(unsigned long ticks) } /** - * ktime_get_update_offsets_tick - hrtimer helper - * @offs_real: pointer to storage for monotonic -> realtime offset - * @offs_boot: pointer to storage for monotonic -> boottime offset - * @offs_tai: pointer to storage for monotonic -> clock tai offset - * - * Returns monotonic time at last tick and various offsets - */ -ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, ktime_t *offs_boot, - ktime_t *offs_tai) -{ - struct timekeeper *tk = &tk_core.timekeeper; - unsigned int seq; - ktime_t base; - u64 nsecs; - - do { - seq = read_seqcount_begin(&tk_core.seq); - - base = tk->tkr_mono.base; - nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; - - *offs_real = tk->offs_real; - *offs_boot = tk->offs_boot; - *offs_tai = tk->offs_tai; - } while (read_seqcount_retry(&tk_core.seq, seq)); - - return ktime_add_ns(base, nsecs); -} - -#ifdef CONFIG_HIGH_RES_TIMERS -/** * ktime_get_update_offsets_now - hrtimer helper + * @cwsseq: pointer to check and store the clock was set sequence number * @offs_real: pointer to storage for monotonic -> realtime offset * @offs_boot: pointer to storage for monotonic -> boottime offset * @offs_tai: pointer to storage for monotonic -> clock tai offset * - * Returns current monotonic time and updates the offsets + * Returns current monotonic time and updates the offsets if the + * sequence number in @cwsseq and timekeeper.clock_was_set_seq are + * different. + * * Called from hrtimer_interrupt() or retrigger_next_event() */ -ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot, - ktime_t *offs_tai) +ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, + ktime_t *offs_boot, ktime_t *offs_tai) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; @@ -1978,15 +1954,16 @@ ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot, base = tk->tkr_mono.base; nsecs = timekeeping_get_ns(&tk->tkr_mono); - - *offs_real = tk->offs_real; - *offs_boot = tk->offs_boot; - *offs_tai = tk->offs_tai; + if (*cwsseq != tk->clock_was_set_seq) { + *cwsseq = tk->clock_was_set_seq; + *offs_real = tk->offs_real; + *offs_boot = tk->offs_boot; + *offs_tai = tk->offs_tai; + } } while (read_seqcount_retry(&tk_core.seq, seq)); return ktime_add_ns(base, nsecs); } -#endif /** * do_adjtimex() - Accessor function to NTP __do_adjtimex function diff --git a/kernel/time/timekeeping.h b/kernel/time/timekeeping.h index ead8794..704f595 100644 --- a/kernel/time/timekeeping.h +++ b/kernel/time/timekeeping.h @@ -3,19 +3,16 @@ /* * Internal interfaces for kernel/time/ */ -extern ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, - ktime_t *offs_boot, - ktime_t *offs_tai); -extern ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, - ktime_t *offs_boot, - ktime_t *offs_tai); +extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, + ktime_t *offs_real, + ktime_t *offs_boot, + ktime_t *offs_tai); extern int timekeeping_valid_for_hres(void); extern u64 timekeeping_max_deferment(void); extern int timekeeping_inject_offset(struct timespec *ts); extern s32 timekeeping_get_tai_offset(void); extern void timekeeping_set_tai_offset(s32 tai_offset); -extern void timekeeping_clocktai(struct timespec *ts); extern int timekeeping_suspend(void); extern void timekeeping_resume(void); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 2ece3aa..d4af7c5 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -49,6 +49,8 @@ #include <asm/timex.h> #include <asm/io.h> +#include "tick-internal.h" + #define CREATE_TRACE_POINTS #include <trace/events/timer.h> @@ -434,7 +436,7 @@ static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) * require special care against races with idle_cpu(), lets deal * with that later. */ - if (!tbase_get_deferrable(base) || tick_nohz_full_cpu(base->cpu)) + if (!tbase_get_deferrable(timer->base) || tick_nohz_full_cpu(base->cpu)) wake_up_nohz_cpu(base->cpu); } @@ -1311,54 +1313,48 @@ cascade: * Check, if the next hrtimer event is before the next timer wheel * event: */ -static unsigned long cmp_next_hrtimer_event(unsigned long now, - unsigned long expires) +static u64 cmp_next_hrtimer_event(u64 basem, u64 expires) { - ktime_t hr_delta = hrtimer_get_next_event(); - struct timespec tsdelta; - unsigned long delta; - - if (hr_delta.tv64 == KTIME_MAX) - return expires; + u64 nextevt = hrtimer_get_next_event(); /* - * Expired timer available, let it expire in the next tick + * If high resolution timers are enabled + * hrtimer_get_next_event() returns KTIME_MAX. */ - if (hr_delta.tv64 <= 0) - return now + 1; - - tsdelta = ktime_to_timespec(hr_delta); - delta = timespec_to_jiffies(&tsdelta); + if (expires <= nextevt) + return expires; /* - * Limit the delta to the max value, which is checked in - * tick_nohz_stop_sched_tick(): + * If the next timer is already expired, return the tick base + * time so the tick is fired immediately. */ - if (delta > NEXT_TIMER_MAX_DELTA) - delta = NEXT_TIMER_MAX_DELTA; + if (nextevt <= basem) + return basem; /* - * Take rounding errors in to account and make sure, that it - * expires in the next tick. Otherwise we go into an endless - * ping pong due to tick_nohz_stop_sched_tick() retriggering - * the timer softirq + * Round up to the next jiffie. High resolution timers are + * off, so the hrtimers are expired in the tick and we need to + * make sure that this tick really expires the timer to avoid + * a ping pong of the nohz stop code. + * + * Use DIV_ROUND_UP_ULL to prevent gcc calling __divdi3 */ - if (delta < 1) - delta = 1; - now += delta; - if (time_before(now, expires)) - return now; - return expires; + return DIV_ROUND_UP_ULL(nextevt, TICK_NSEC) * TICK_NSEC; } /** - * get_next_timer_interrupt - return the jiffy of the next pending timer - * @now: current time (in jiffies) + * get_next_timer_interrupt - return the time (clock mono) of the next timer + * @basej: base time jiffies + * @basem: base time clock monotonic + * + * Returns the tick aligned clock monotonic time of the next pending + * timer or KTIME_MAX if no timer is pending. */ -unsigned long get_next_timer_interrupt(unsigned long now) +u64 get_next_timer_interrupt(unsigned long basej, u64 basem) { struct tvec_base *base = __this_cpu_read(tvec_bases); - unsigned long expires = now + NEXT_TIMER_MAX_DELTA; + u64 expires = KTIME_MAX; + unsigned long nextevt; /* * Pretend that there is no timer pending if the cpu is offline. @@ -1371,14 +1367,15 @@ unsigned long get_next_timer_interrupt(unsigned long now) if (base->active_timers) { if (time_before_eq(base->next_timer, base->timer_jiffies)) base->next_timer = __next_timer_interrupt(base); - expires = base->next_timer; + nextevt = base->next_timer; + if (time_before_eq(nextevt, basej)) + expires = basem; + else + expires = basem + (nextevt - basej) * TICK_NSEC; } spin_unlock(&base->lock); - if (time_before_eq(expires, now)) - return now; - - return cmp_next_hrtimer_event(now, expires); + return cmp_next_hrtimer_event(basem, expires); } #endif @@ -1409,8 +1406,6 @@ static void run_timer_softirq(struct softirq_action *h) { struct tvec_base *base = __this_cpu_read(tvec_bases); - hrtimer_run_pending(); - if (time_after_eq(jiffies, base->timer_jiffies)) __run_timers(base); } @@ -1697,14 +1692,14 @@ unsigned long msleep_interruptible(unsigned int msecs) EXPORT_SYMBOL(msleep_interruptible); -static int __sched do_usleep_range(unsigned long min, unsigned long max) +static void __sched do_usleep_range(unsigned long min, unsigned long max) { ktime_t kmin; unsigned long delta; kmin = ktime_set(0, min * NSEC_PER_USEC); delta = (max - min) * NSEC_PER_USEC; - return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL); + schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL); } /** @@ -1712,7 +1707,7 @@ static int __sched do_usleep_range(unsigned long min, unsigned long max) * @min: Minimum time in usecs to sleep * @max: Maximum time in usecs to sleep */ -void usleep_range(unsigned long min, unsigned long max) +void __sched usleep_range(unsigned long min, unsigned long max) { __set_current_state(TASK_UNINTERRUPTIBLE); do_usleep_range(min, max); diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index e878c2e..18b074b 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -35,13 +35,20 @@ DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases); * This allows printing both to /proc/timer_list and * to the console (on SysRq-Q): */ -#define SEQ_printf(m, x...) \ - do { \ - if (m) \ - seq_printf(m, x); \ - else \ - printk(x); \ - } while (0) +__printf(2, 3) +static void SEQ_printf(struct seq_file *m, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + + if (m) + seq_vprintf(m, fmt, args); + else + vprintk(fmt, args); + + va_end(args); +} static void print_name_offset(struct seq_file *m, void *sym) { @@ -120,10 +127,10 @@ static void print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) { SEQ_printf(m, " .base: %pK\n", base); - SEQ_printf(m, " .index: %d\n", - base->index); - SEQ_printf(m, " .resolution: %Lu nsecs\n", - (unsigned long long)ktime_to_ns(base->resolution)); + SEQ_printf(m, " .index: %d\n", base->index); + + SEQ_printf(m, " .resolution: %u nsecs\n", (unsigned) hrtimer_resolution); + SEQ_printf(m, " .get_time: "); print_name_offset(m, base->get_time); SEQ_printf(m, "\n"); @@ -158,7 +165,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) P(nr_events); P(nr_retries); P(nr_hangs); - P_ns(max_hang_time); + P(max_hang_time); #endif #undef P #undef P_ns @@ -184,7 +191,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) P_ns(idle_sleeptime); P_ns(iowait_sleeptime); P(last_jiffies); - P(next_jiffies); + P(next_timer); P_ns(idle_expires); SEQ_printf(m, "jiffies: %Lu\n", (unsigned long long)jiffies); @@ -269,11 +276,11 @@ static void timer_list_show_tickdevices_header(struct seq_file *m) { #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST print_tickdevice(m, tick_get_broadcast_device(), -1); - SEQ_printf(m, "tick_broadcast_mask: %08lx\n", - cpumask_bits(tick_get_broadcast_mask())[0]); + SEQ_printf(m, "tick_broadcast_mask: %*pb\n", + cpumask_pr_args(tick_get_broadcast_mask())); #ifdef CONFIG_TICK_ONESHOT - SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n", - cpumask_bits(tick_get_broadcast_oneshot_mask())[0]); + SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", + cpumask_pr_args(tick_get_broadcast_oneshot_mask())); #endif SEQ_printf(m, "\n"); #endif @@ -282,7 +289,7 @@ static void timer_list_show_tickdevices_header(struct seq_file *m) static inline void timer_list_header(struct seq_file *m, u64 now) { - SEQ_printf(m, "Timer List Version: v0.7\n"); + SEQ_printf(m, "Timer List Version: v0.8\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); SEQ_printf(m, "\n"); diff --git a/lib/timerqueue.c b/lib/timerqueue.c index a382e4a..782ae8c 100644 --- a/lib/timerqueue.c +++ b/lib/timerqueue.c @@ -36,7 +36,7 @@ * Adds the timer node to the timerqueue, sorted by the * node's expires value. */ -void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node) +bool timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node) { struct rb_node **p = &head->head.rb_node; struct rb_node *parent = NULL; @@ -56,8 +56,11 @@ void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node) rb_link_node(&node->node, parent, p); rb_insert_color(&node->node, &head->head); - if (!head->next || node->expires.tv64 < head->next->expires.tv64) + if (!head->next || node->expires.tv64 < head->next->expires.tv64) { head->next = node; + return true; + } + return false; } EXPORT_SYMBOL_GPL(timerqueue_add); @@ -69,7 +72,7 @@ EXPORT_SYMBOL_GPL(timerqueue_add); * * Removes the timer node from the timerqueue. */ -void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node) +bool timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node) { WARN_ON_ONCE(RB_EMPTY_NODE(&node->node)); @@ -82,6 +85,7 @@ void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node) } rb_erase(&node->node, &head->head); RB_CLEAR_NODE(&node->node); + return head->next != NULL; } EXPORT_SYMBOL_GPL(timerqueue_del); diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 508155b..54817d3 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -2212,8 +2212,6 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until) do { set_current_state(TASK_INTERRUPTIBLE); hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS); - if (!hrtimer_active(&t.timer)) - t.task = NULL; if (likely(t.task)) schedule(); diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index ad9eed7..45bc63a 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1883,13 +1883,10 @@ EXPORT_SYMBOL(tcf_destroy_chain); #ifdef CONFIG_PROC_FS static int psched_show(struct seq_file *seq, void *v) { - struct timespec ts; - - hrtimer_get_res(CLOCK_MONOTONIC, &ts); seq_printf(seq, "%08x %08x %08x %08x\n", (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 1000000, - (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts))); + (u32)NSEC_PER_SEC / hrtimer_resolution); return 0; } diff --git a/sound/core/hrtimer.c b/sound/core/hrtimer.c index 886be7d..f845ecf 100644 --- a/sound/core/hrtimer.c +++ b/sound/core/hrtimer.c @@ -121,16 +121,9 @@ static struct snd_timer *mytimer; static int __init snd_hrtimer_init(void) { struct snd_timer *timer; - struct timespec tp; int err; - hrtimer_get_res(CLOCK_MONOTONIC, &tp); - if (tp.tv_sec > 0 || !tp.tv_nsec) { - pr_err("snd-hrtimer: Invalid resolution %u.%09u", - (unsigned)tp.tv_sec, (unsigned)tp.tv_nsec); - return -EINVAL; - } - resolution = tp.tv_nsec; + resolution = hrtimer_resolution; /* Create a new timer and set up the fields */ err = snd_timer_global_new("hrtimer", SNDRV_TIMER_GLOBAL_HRTIMER, diff --git a/sound/drivers/pcsp/pcsp.c b/sound/drivers/pcsp/pcsp.c index d9647bd..27e25bb 100644 --- a/sound/drivers/pcsp/pcsp.c +++ b/sound/drivers/pcsp/pcsp.c @@ -42,16 +42,13 @@ struct snd_pcsp pcsp_chip; static int snd_pcsp_create(struct snd_card *card) { static struct snd_device_ops ops = { }; - struct timespec tp; - int err; - int div, min_div, order; - - hrtimer_get_res(CLOCK_MONOTONIC, &tp); + unsigned int resolution = hrtimer_resolution; + int err, div, min_div, order; if (!nopcm) { - if (tp.tv_sec || tp.tv_nsec > PCSP_MAX_PERIOD_NS) { + if (resolution > PCSP_MAX_PERIOD_NS) { printk(KERN_ERR "PCSP: Timer resolution is not sufficient " - "(%linS)\n", tp.tv_nsec); + "(%unS)\n", resolution); printk(KERN_ERR "PCSP: Make sure you have HPET and ACPI " "enabled.\n"); printk(KERN_ERR "PCSP: Turned into nopcm mode.\n"); @@ -59,13 +56,13 @@ static int snd_pcsp_create(struct snd_card *card) } } - if (loops_per_jiffy >= PCSP_MIN_LPJ && tp.tv_nsec <= PCSP_MIN_PERIOD_NS) + if (loops_per_jiffy >= PCSP_MIN_LPJ && resolution <= PCSP_MIN_PERIOD_NS) min_div = MIN_DIV; else min_div = MAX_DIV; #if PCSP_DEBUG - printk(KERN_DEBUG "PCSP: lpj=%li, min_div=%i, res=%li\n", - loops_per_jiffy, min_div, tp.tv_nsec); + printk(KERN_DEBUG "PCSP: lpj=%li, min_div=%i, res=%u\n", + loops_per_jiffy, min_div, resolution); #endif div = MAX_DIV / min_div; |
