diff options
| -rw-r--r-- | include/linux/hrtimer.h | 5 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 270 | ||||
| -rw-r--r-- | kernel/timer.c | 3 |
3 files changed, 143 insertions, 135 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index ecc8e2685e2b..49067f14fac1 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -115,10 +115,8 @@ struct hrtimer { enum hrtimer_restart (*function)(struct hrtimer *); struct hrtimer_clock_base *base; unsigned long state; -#ifdef CONFIG_HIGH_RES_TIMERS enum hrtimer_cb_mode cb_mode; struct list_head cb_entry; -#endif #ifdef CONFIG_TIMER_STATS void *start_site; char start_comm[16]; @@ -194,10 +192,10 @@ struct hrtimer_cpu_base { spinlock_t lock; struct lock_class_key lock_key; struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; + struct list_head cb_pending; #ifdef CONFIG_HIGH_RES_TIMERS ktime_t expires_next; int hres_active; - struct list_head cb_pending; unsigned long nr_events; #endif }; @@ -319,6 +317,7 @@ extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, /* 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/kernel/hrtimer.c b/kernel/hrtimer.c index 9f850ca032b6..061ae28a36a0 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -325,6 +325,22 @@ unsigned long ktime_divns(const ktime_t kt, s64 div) } #endif /* BITS_PER_LONG >= 64 */ +/* + * Check, whether the timer is on the callback pending list + */ +static inline int hrtimer_cb_pending(const struct hrtimer *timer) +{ + return timer->state & HRTIMER_STATE_PENDING; +} + +/* + * Remove a timer from the callback pending list + */ +static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) +{ + list_del_init(&timer->cb_entry); +} + /* High resolution timer related functions */ #ifdef CONFIG_HIGH_RES_TIMERS @@ -494,29 +510,12 @@ void hres_timers_resume(void) } /* - * Check, whether the timer is on the callback pending list - */ -static inline int hrtimer_cb_pending(const struct hrtimer *timer) -{ - return timer->state & HRTIMER_STATE_PENDING; -} - -/* - * Remove a timer from the callback pending list - */ -static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) -{ - list_del_init(&timer->cb_entry); -} - -/* * Initialize the high resolution related parts of cpu_base */ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { base->expires_next.tv64 = KTIME_MAX; base->hres_active = 0; - INIT_LIST_HEAD(&base->cb_pending); } /* @@ -524,7 +523,6 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) */ static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { - INIT_LIST_HEAD(&timer->cb_entry); } /* @@ -618,10 +616,13 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, { return 0; } -static inline int hrtimer_cb_pending(struct hrtimer *timer) { return 0; } -static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) { } static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { } +static inline int hrtimer_reprogram(struct hrtimer *timer, + struct hrtimer_clock_base *base) +{ + return 0; +} #endif /* CONFIG_HIGH_RES_TIMERS */ @@ -1001,6 +1002,7 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, clock_id = CLOCK_MONOTONIC; timer->base = &cpu_base->clock_base[clock_id]; + INIT_LIST_HEAD(&timer->cb_entry); hrtimer_init_timer_hres(timer); #ifdef CONFIG_TIMER_STATS @@ -1030,6 +1032,85 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) } EXPORT_SYMBOL_GPL(hrtimer_get_res); +static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base) +{ + spin_lock_irq(&cpu_base->lock); + + while (!list_empty(&cpu_base->cb_pending)) { + enum hrtimer_restart (*fn)(struct hrtimer *); + struct hrtimer *timer; + int restart; + + timer = list_entry(cpu_base->cb_pending.next, + struct hrtimer, cb_entry); + + timer_stats_account_hrtimer(timer); + + fn = timer->function; + __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0); + spin_unlock_irq(&cpu_base->lock); + + restart = fn(timer); + + spin_lock_irq(&cpu_base->lock); + + timer->state &= ~HRTIMER_STATE_CALLBACK; + if (restart == HRTIMER_RESTART) { + BUG_ON(hrtimer_active(timer)); + /* + * Enqueue the timer, allow reprogramming of the event + * device + */ + enqueue_hrtimer(timer, timer->base, 1); + } else if (hrtimer_active(timer)) { + /* + * If the timer was rearmed on another CPU, reprogram + * the event device. + */ + if (timer->base->first == &timer->node) + hrtimer_reprogram(timer, timer->base); + } + } + spin_unlock_irq(&cpu_base->lock); +} + +static void __run_hrtimer(struct hrtimer *timer) +{ + struct hrtimer_clock_base *base = timer->base; + struct hrtimer_cpu_base *cpu_base = base->cpu_base; + enum hrtimer_restart (*fn)(struct hrtimer *); + int restart; + + __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); + timer_stats_account_hrtimer(timer); + + fn = timer->function; + if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) { + /* + * Used for scheduler timers, avoid lock inversion with + * rq->lock and tasklist_lock. + * + * These timers are required to deal with enqueue expiry + * themselves and are not allowed to migrate. + */ + spin_unlock(&cpu_base->lock); + restart = fn(timer); + spin_lock(&cpu_base->lock); + } else + restart = fn(timer); + + /* + * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid + * reprogramming of the event hardware. This happens at the end of this + * function anyway. + */ + if (restart != HRTIMER_NORESTART) { + BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); + enqueue_hrtimer(timer, base, 0); + } + timer->state &= ~HRTIMER_STATE_CALLBACK; +} + #ifdef CONFIG_HIGH_RES_TIMERS /* @@ -1063,9 +1144,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) basenow = ktime_add(now, base->offset); while ((node = base->first)) { - enum hrtimer_restart (*fn)(struct hrtimer *); struct hrtimer *timer; - int restart; timer = rb_entry(node, struct hrtimer, node); @@ -1089,37 +1168,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) continue; } - __remove_hrtimer(timer, base, - HRTIMER_STATE_CALLBACK, 0); - timer_stats_account_hrtimer(timer); - - fn = timer->function; - if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) { - /* - * Used for scheduler timers, avoid lock - * inversion with rq->lock and tasklist_lock. - * - * These timers are required to deal with - * enqueue expiry themselves and are not - * allowed to migrate. - */ - spin_unlock(&cpu_base->lock); - restart = fn(timer); - spin_lock(&cpu_base->lock); - } else - restart = fn(timer); - - /* - * Note: We clear the CALLBACK bit after - * enqueue_hrtimer to avoid reprogramming of - * the event hardware. This happens at the end - * of this function anyway. - */ - if (restart != HRTIMER_NORESTART) { - BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); - enqueue_hrtimer(timer, base, 0); - } - timer->state &= ~HRTIMER_STATE_CALLBACK; + __run_hrtimer(timer); } spin_unlock(&cpu_base->lock); base++; @@ -1140,52 +1189,41 @@ void hrtimer_interrupt(struct clock_event_device *dev) static void run_hrtimer_softirq(struct softirq_action *h) { - struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - - spin_lock_irq(&cpu_base->lock); - - while (!list_empty(&cpu_base->cb_pending)) { - enum hrtimer_restart (*fn)(struct hrtimer *); - struct hrtimer *timer; - int restart; - - timer = list_entry(cpu_base->cb_pending.next, - struct hrtimer, cb_entry); + run_hrtimer_pending(&__get_cpu_var(hrtimer_bases)); +} - timer_stats_account_hrtimer(timer); +#endif /* CONFIG_HIGH_RES_TIMERS */ - fn = timer->function; - __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0); - spin_unlock_irq(&cpu_base->lock); +/* + * 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. + */ +void hrtimer_run_pending(void) +{ + struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - restart = fn(timer); + if (hrtimer_hres_active()) + return; - spin_lock_irq(&cpu_base->lock); + /* + * 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. + */ + if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) + hrtimer_switch_to_hres(); - timer->state &= ~HRTIMER_STATE_CALLBACK; - if (restart == HRTIMER_RESTART) { - BUG_ON(hrtimer_active(timer)); - /* - * Enqueue the timer, allow reprogramming of the event - * device - */ - enqueue_hrtimer(timer, timer->base, 1); - } else if (hrtimer_active(timer)) { - /* - * If the timer was rearmed on another CPU, reprogram - * the event device. - */ - if (timer->base->first == &timer->node) - hrtimer_reprogram(timer, timer->base); - } - } - spin_unlock_irq(&cpu_base->lock); + run_hrtimer_pending(cpu_base); } -#endif /* CONFIG_HIGH_RES_TIMERS */ - /* - * Expire the per base hrtimer-queue: + * Called from hardirq context every jiffy */ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base, int index) @@ -1199,46 +1237,27 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base, if (base->get_softirq_time) base->softirq_time = base->get_softirq_time(); - spin_lock_irq(&cpu_base->lock); + spin_lock(&cpu_base->lock); while ((node = base->first)) { struct hrtimer *timer; - enum hrtimer_restart (*fn)(struct hrtimer *); - int restart; timer = rb_entry(node, struct hrtimer, node); if (base->softirq_time.tv64 <= timer->expires.tv64) break; -#ifdef CONFIG_HIGH_RES_TIMERS - WARN_ON_ONCE(timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ); -#endif - timer_stats_account_hrtimer(timer); - - fn = timer->function; - __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); - spin_unlock_irq(&cpu_base->lock); - - restart = fn(timer); - - spin_lock_irq(&cpu_base->lock); - - timer->state &= ~HRTIMER_STATE_CALLBACK; - if (restart != HRTIMER_NORESTART) { - BUG_ON(hrtimer_active(timer)); - enqueue_hrtimer(timer, base, 0); + if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { + __remove_hrtimer(timer, base, HRTIMER_STATE_PENDING, 0); + list_add_tail(&timer->cb_entry, + &base->cpu_base->cb_pending); + continue; } + + __run_hrtimer(timer); } - spin_unlock_irq(&cpu_base->lock); + spin_unlock(&cpu_base->lock); } -/* - * 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. - */ void hrtimer_run_queues(void) { struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); @@ -1247,18 +1266,6 @@ void hrtimer_run_queues(void) if (hrtimer_hres_active()) 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. - */ - if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) - if (hrtimer_switch_to_hres()) - return; - hrtimer_get_softirq_time(cpu_base); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) @@ -1407,6 +1414,7 @@ static void __cpuinit init_hrtimers_cpu(int cpu) for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) cpu_base->clock_base[i].cpu_base = cpu_base; + INIT_LIST_HEAD(&cpu_base->cb_pending); hrtimer_init_hres(cpu_base); } diff --git a/kernel/timer.c b/kernel/timer.c index 2a00c22203f3..f739dfb539ce 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -896,7 +896,7 @@ static void run_timer_softirq(struct softirq_action *h) { tvec_base_t *base = __get_cpu_var(tvec_bases); - hrtimer_run_queues(); + hrtimer_run_pending(); if (time_after_eq(jiffies, base->timer_jiffies)) __run_timers(base); @@ -907,6 +907,7 @@ static void run_timer_softirq(struct softirq_action *h) */ void run_local_timers(void) { + hrtimer_run_queues(); raise_softirq(TIMER_SOFTIRQ); softlockup_tick(); } |