diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-02-22 22:04:41 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-02-22 22:04:41 +0000 |
commit | 61b80086a525c8a6081257ae40da5dee2bcaee16 (patch) | |
tree | 675da35e4c03be3a5ca17bf6430e5b51dfed6296 /kernel | |
parent | a5f17d1f4c2831b9b9bf8b1a537cdbac995d6e13 (diff) | |
parent | 230f984662d7e0e4a9597c665fd4f53130666e7d (diff) | |
download | op-kernel-dev-61b80086a525c8a6081257ae40da5dee2bcaee16.zip op-kernel-dev-61b80086a525c8a6081257ae40da5dee2bcaee16.tar.gz |
Merge branch 'entry-macro-cleanup' of git://sources.calxeda.com/kernel/linux into for-armsoc
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/events/core.c | 104 | ||||
-rw-r--r-- | kernel/exit.c | 16 | ||||
-rw-r--r-- | kernel/fork.c | 20 | ||||
-rw-r--r-- | kernel/kprobes.c | 6 | ||||
-rw-r--r-- | kernel/power/power.h | 24 | ||||
-rw-r--r-- | kernel/power/process.c | 7 | ||||
-rw-r--r-- | kernel/power/user.c | 6 | ||||
-rw-r--r-- | kernel/sched/core.c | 19 | ||||
-rw-r--r-- | kernel/sched/fair.c | 34 | ||||
-rw-r--r-- | kernel/sched/rt.c | 5 | ||||
-rw-r--r-- | kernel/watchdog.c | 2 |
11 files changed, 180 insertions, 63 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 32b48c8..ba36013 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2300,6 +2300,9 @@ do { \ return div64_u64(dividend, divisor); } +static DEFINE_PER_CPU(int, perf_throttled_count); +static DEFINE_PER_CPU(u64, perf_throttled_seq); + static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) { struct hw_perf_event *hwc = &event->hw; @@ -2325,16 +2328,29 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) } } -static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period) +/* + * combine freq adjustment with unthrottling to avoid two passes over the + * events. At the same time, make sure, having freq events does not change + * the rate of unthrottling as that would introduce bias. + */ +static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, + int needs_unthr) { struct perf_event *event; struct hw_perf_event *hwc; - u64 interrupts, now; + u64 now, period = TICK_NSEC; s64 delta; - if (!ctx->nr_freq) + /* + * only need to iterate over all events iff: + * - context have events in frequency mode (needs freq adjust) + * - there are events to unthrottle on this cpu + */ + if (!(ctx->nr_freq || needs_unthr)) return; + raw_spin_lock(&ctx->lock); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { if (event->state != PERF_EVENT_STATE_ACTIVE) continue; @@ -2344,13 +2360,8 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period) hwc = &event->hw; - interrupts = hwc->interrupts; - hwc->interrupts = 0; - - /* - * unthrottle events on the tick - */ - if (interrupts == MAX_INTERRUPTS) { + if (needs_unthr && hwc->interrupts == MAX_INTERRUPTS) { + hwc->interrupts = 0; perf_log_throttle(event, 1); event->pmu->start(event, 0); } @@ -2358,14 +2369,26 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period) if (!event->attr.freq || !event->attr.sample_freq) continue; - event->pmu->read(event); + /* + * stop the event and update event->count + */ + event->pmu->stop(event, PERF_EF_UPDATE); + now = local64_read(&event->count); delta = now - hwc->freq_count_stamp; hwc->freq_count_stamp = now; + /* + * restart the event + * reload only if value has changed + */ if (delta > 0) perf_adjust_period(event, period, delta); + + event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); } + + raw_spin_unlock(&ctx->lock); } /* @@ -2388,16 +2411,13 @@ static void rotate_ctx(struct perf_event_context *ctx) */ static void perf_rotate_context(struct perf_cpu_context *cpuctx) { - u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC; struct perf_event_context *ctx = NULL; - int rotate = 0, remove = 1, freq = 0; + int rotate = 0, remove = 1; if (cpuctx->ctx.nr_events) { remove = 0; if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) rotate = 1; - if (cpuctx->ctx.nr_freq) - freq = 1; } ctx = cpuctx->task_ctx; @@ -2405,37 +2425,26 @@ static void perf_rotate_context(struct perf_cpu_context *cpuctx) remove = 0; if (ctx->nr_events != ctx->nr_active) rotate = 1; - if (ctx->nr_freq) - freq = 1; } - if (!rotate && !freq) + if (!rotate) goto done; perf_ctx_lock(cpuctx, cpuctx->task_ctx); perf_pmu_disable(cpuctx->ctx.pmu); - if (freq) { - perf_ctx_adjust_freq(&cpuctx->ctx, interval); - if (ctx) - perf_ctx_adjust_freq(ctx, interval); - } - - if (rotate) { - cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); - if (ctx) - ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); + cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); + if (ctx) + ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); - rotate_ctx(&cpuctx->ctx); - if (ctx) - rotate_ctx(ctx); + rotate_ctx(&cpuctx->ctx); + if (ctx) + rotate_ctx(ctx); - perf_event_sched_in(cpuctx, ctx, current); - } + perf_event_sched_in(cpuctx, ctx, current); perf_pmu_enable(cpuctx->ctx.pmu); perf_ctx_unlock(cpuctx, cpuctx->task_ctx); - done: if (remove) list_del_init(&cpuctx->rotation_list); @@ -2445,10 +2454,22 @@ void perf_event_task_tick(void) { struct list_head *head = &__get_cpu_var(rotation_list); struct perf_cpu_context *cpuctx, *tmp; + struct perf_event_context *ctx; + int throttled; WARN_ON(!irqs_disabled()); + __this_cpu_inc(perf_throttled_seq); + throttled = __this_cpu_xchg(perf_throttled_count, 0); + list_for_each_entry_safe(cpuctx, tmp, head, rotation_list) { + ctx = &cpuctx->ctx; + perf_adjust_freq_unthr_context(ctx, throttled); + + ctx = cpuctx->task_ctx; + if (ctx) + perf_adjust_freq_unthr_context(ctx, throttled); + if (cpuctx->jiffies_interval == 1 || !(jiffies % cpuctx->jiffies_interval)) perf_rotate_context(cpuctx); @@ -4509,6 +4530,7 @@ static int __perf_event_overflow(struct perf_event *event, { int events = atomic_read(&event->event_limit); struct hw_perf_event *hwc = &event->hw; + u64 seq; int ret = 0; /* @@ -4518,14 +4540,20 @@ static int __perf_event_overflow(struct perf_event *event, if (unlikely(!is_sampling_event(event))) return 0; - if (unlikely(hwc->interrupts >= max_samples_per_tick)) { - if (throttle) { + seq = __this_cpu_read(perf_throttled_seq); + if (seq != hwc->interrupts_seq) { + hwc->interrupts_seq = seq; + hwc->interrupts = 1; + } else { + hwc->interrupts++; + if (unlikely(throttle + && hwc->interrupts >= max_samples_per_tick)) { + __this_cpu_inc(perf_throttled_count); hwc->interrupts = MAX_INTERRUPTS; perf_log_throttle(event, 0); ret = 1; } - } else - hwc->interrupts++; + } if (event->attr.freq) { u64 now = perf_clock(); diff --git a/kernel/exit.c b/kernel/exit.c index 294b170..4b4042f 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1038,6 +1038,22 @@ void do_exit(long code) if (tsk->nr_dirtied) __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied); exit_rcu(); + + /* + * The setting of TASK_RUNNING by try_to_wake_up() may be delayed + * when the following two conditions become true. + * - There is race condition of mmap_sem (It is acquired by + * exit_mm()), and + * - SMI occurs before setting TASK_RUNINNG. + * (or hypervisor of virtual machine switches to other guest) + * As a result, we may become TASK_RUNNING after becoming TASK_DEAD + * + * To avoid it, we have to wait for releasing tsk->pi_lock which + * is held by try_to_wake_up() + */ + smp_mb(); + raw_spin_unlock_wait(&tsk->pi_lock); + /* causes final put_task_struct in finish_task_switch(). */ tsk->state = TASK_DEAD; tsk->flags |= PF_NOFREEZE; /* tell freezer to ignore us */ diff --git a/kernel/fork.c b/kernel/fork.c index 051f090..1b2ef3c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -647,6 +647,26 @@ struct mm_struct *get_task_mm(struct task_struct *task) } EXPORT_SYMBOL_GPL(get_task_mm); +struct mm_struct *mm_access(struct task_struct *task, unsigned int mode) +{ + struct mm_struct *mm; + int err; + + err = mutex_lock_killable(&task->signal->cred_guard_mutex); + if (err) + return ERR_PTR(err); + + mm = get_task_mm(task); + if (mm && mm != current->mm && + !ptrace_may_access(task, mode)) { + mmput(mm); + mm = ERR_PTR(-EACCES); + } + mutex_unlock(&task->signal->cred_guard_mutex); + + return mm; +} + /* Please note the differences between mmput and mm_release. * mmput is called whenever we stop holding onto a mm_struct, * error success whatever. diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 29f5b65..9788c0e 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1673,8 +1673,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, ri->rp = rp; ri->task = current; - if (rp->entry_handler && rp->entry_handler(ri, regs)) + if (rp->entry_handler && rp->entry_handler(ri, regs)) { + raw_spin_lock_irqsave(&rp->lock, flags); + hlist_add_head(&ri->hlist, &rp->free_instances); + raw_spin_unlock_irqrestore(&rp->lock, flags); return 0; + } arch_prepare_kretprobe(ri, regs); diff --git a/kernel/power/power.h b/kernel/power/power.h index 0c4defe..21724ee 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -231,8 +231,28 @@ extern int pm_test_level; #ifdef CONFIG_SUSPEND_FREEZER static inline int suspend_freeze_processes(void) { - int error = freeze_processes(); - return error ? : freeze_kernel_threads(); + int error; + + error = freeze_processes(); + + /* + * freeze_processes() automatically thaws every task if freezing + * fails. So we need not do anything extra upon error. + */ + if (error) + goto Finish; + + error = freeze_kernel_threads(); + + /* + * freeze_kernel_threads() thaws only kernel threads upon freezing + * failure. So we have to thaw the userspace tasks ourselves. + */ + if (error) + thaw_processes(); + + Finish: + return error; } static inline void suspend_thaw_processes(void) diff --git a/kernel/power/process.c b/kernel/power/process.c index eeca003..7e42645 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -143,7 +143,10 @@ int freeze_processes(void) /** * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator. * - * On success, returns 0. On failure, -errno and system is fully thawed. + * On success, returns 0. On failure, -errno and only the kernel threads are + * thawed, so as to give a chance to the caller to do additional cleanups + * (if any) before thawing the userspace tasks. So, it is the responsibility + * of the caller to thaw the userspace tasks, when the time is right. */ int freeze_kernel_threads(void) { @@ -159,7 +162,7 @@ int freeze_kernel_threads(void) BUG_ON(in_atomic()); if (error) - thaw_processes(); + thaw_kernel_threads(); return error; } diff --git a/kernel/power/user.c b/kernel/power/user.c index e5a21a8..3e10007 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -249,13 +249,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, } pm_restore_gfp_mask(); error = hibernation_snapshot(data->platform_support); - if (!error) { + if (error) { + thaw_kernel_threads(); + } else { error = put_user(in_suspend, (int __user *)arg); if (!error && !freezer_test_done) data->ready = 1; if (freezer_test_done) { freezer_test_done = false; - thaw_processes(); + thaw_kernel_threads(); } } break; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index df00cb0..5255c9d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -74,6 +74,7 @@ #include <asm/tlb.h> #include <asm/irq_regs.h> +#include <asm/mutex.h> #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h> #endif @@ -723,9 +724,6 @@ static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) p->sched_class->dequeue_task(rq, p, flags); } -/* - * activate_task - move a task to the runqueue. - */ void activate_task(struct rq *rq, struct task_struct *p, int flags) { if (task_contributes_to_load(p)) @@ -734,9 +732,6 @@ void activate_task(struct rq *rq, struct task_struct *p, int flags) enqueue_task(rq, p, flags); } -/* - * deactivate_task - remove a task from the runqueue. - */ void deactivate_task(struct rq *rq, struct task_struct *p, int flags) { if (task_contributes_to_load(p)) @@ -4134,7 +4129,7 @@ recheck: on_rq = p->on_rq; running = task_current(rq, p); if (on_rq) - deactivate_task(rq, p, 0); + dequeue_task(rq, p, 0); if (running) p->sched_class->put_prev_task(rq, p); @@ -4147,7 +4142,7 @@ recheck: if (running) p->sched_class->set_curr_task(rq); if (on_rq) - activate_task(rq, p, 0); + enqueue_task(rq, p, 0); check_class_changed(rq, p, prev_class, oldprio); task_rq_unlock(rq, p, &flags); @@ -4998,9 +4993,9 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) * placed properly. */ if (p->on_rq) { - deactivate_task(rq_src, p, 0); + dequeue_task(rq_src, p, 0); set_task_cpu(p, dest_cpu); - activate_task(rq_dest, p, 0); + enqueue_task(rq_dest, p, 0); check_preempt_curr(rq_dest, p, 0); } done: @@ -7032,10 +7027,10 @@ static void normalize_task(struct rq *rq, struct task_struct *p) on_rq = p->on_rq; if (on_rq) - deactivate_task(rq, p, 0); + dequeue_task(rq, p, 0); __setscheduler(rq, p, SCHED_NORMAL, 0); if (on_rq) { - activate_task(rq, p, 0); + enqueue_task(rq, p, 0); resched_task(rq->curr); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 84adb2d..7c6414f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4866,6 +4866,15 @@ static void nohz_balancer_kick(int cpu) return; } +static inline void clear_nohz_tick_stopped(int cpu) +{ + if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { + cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); + atomic_dec(&nohz.nr_cpus); + clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); + } +} + static inline void set_cpu_sd_state_busy(void) { struct sched_domain *sd; @@ -4904,6 +4913,12 @@ void select_nohz_load_balancer(int stop_tick) { int cpu = smp_processor_id(); + /* + * If this cpu is going down, then nothing needs to be done. + */ + if (!cpu_active(cpu)) + return; + if (stop_tick) { if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu))) return; @@ -4914,6 +4929,18 @@ void select_nohz_load_balancer(int stop_tick) } return; } + +static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DYING: + clear_nohz_tick_stopped(smp_processor_id()); + return NOTIFY_OK; + default: + return NOTIFY_DONE; + } +} #endif static DEFINE_SPINLOCK(balancing); @@ -5070,11 +5097,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu) * busy tick after returning from idle, we will update the busy stats. */ set_cpu_sd_state_busy(); - if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { - clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); - cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); - atomic_dec(&nohz.nr_cpus); - } + clear_nohz_tick_stopped(cpu); /* * None are in tickless mode and hence no need for NOHZ idle load @@ -5590,6 +5613,7 @@ __init void init_sched_fair_class(void) #ifdef CONFIG_NO_HZ zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); + cpu_notifier(sched_ilb_notifier, 0); #endif #endif /* SMP */ diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 3640ebb..f42ae7f 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1587,6 +1587,11 @@ static int push_rt_task(struct rq *rq) if (!next_task) return 0; +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW + if (unlikely(task_running(rq, next_task))) + return 0; +#endif + retry: if (unlikely(next_task == rq->curr)) { WARN_ON(1); diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 1d7bca7..d117262 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -296,7 +296,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) if (__this_cpu_read(soft_watchdog_warn) == true) return HRTIMER_RESTART; - printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", + printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", smp_processor_id(), duration, current->comm, task_pid_nr(current)); print_modules(); |