diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/Kconfig.hz | 2 | ||||
| -rw-r--r-- | kernel/sched.c | 202 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 5 |
3 files changed, 63 insertions, 146 deletions
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz index 526128a2e622..2a202a846757 100644 --- a/kernel/Kconfig.hz +++ b/kernel/Kconfig.hz @@ -55,4 +55,4 @@ config HZ default 1000 if HZ_1000 config SCHED_HRTICK - def_bool HIGH_RES_TIMERS && X86 + def_bool HIGH_RES_TIMERS diff --git a/kernel/sched.c b/kernel/sched.c index 1ee18dbb4516..c13c75e9f9f7 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -571,8 +571,10 @@ struct rq { #endif #ifdef CONFIG_SCHED_HRTICK - unsigned long hrtick_flags; - ktime_t hrtick_expire; +#ifdef CONFIG_SMP + int hrtick_csd_pending; + struct call_single_data hrtick_csd; +#endif struct hrtimer hrtick_timer; #endif @@ -983,13 +985,6 @@ static struct rq *this_rq_lock(void) return rq; } -static void __resched_task(struct task_struct *p, int tif_bit); - -static inline void resched_task(struct task_struct *p) -{ - __resched_task(p, TIF_NEED_RESCHED); -} - #ifdef CONFIG_SCHED_HRTICK /* * Use HR-timers to deliver accurate preemption points. @@ -1001,25 +996,6 @@ static inline void resched_task(struct task_struct *p) * When we get rescheduled we reprogram the hrtick_timer outside of the * rq->lock. */ -static inline void resched_hrt(struct task_struct *p) -{ - __resched_task(p, TIF_HRTICK_RESCHED); -} - -static inline void resched_rq(struct rq *rq) -{ - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - resched_task(rq->curr); - spin_unlock_irqrestore(&rq->lock, flags); -} - -enum { - HRTICK_SET, /* re-programm hrtick_timer */ - HRTICK_RESET, /* not a new slice */ - HRTICK_BLOCK, /* stop hrtick operations */ -}; /* * Use hrtick when: @@ -1030,40 +1006,11 @@ static inline int hrtick_enabled(struct rq *rq) { if (!sched_feat(HRTICK)) return 0; - if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags))) + if (!cpu_online(cpu_of(rq))) return 0; return hrtimer_is_hres_active(&rq->hrtick_timer); } -/* - * Called to set the hrtick timer state. - * - * called with rq->lock held and irqs disabled - */ -static void hrtick_start(struct rq *rq, u64 delay, int reset) -{ - assert_spin_locked(&rq->lock); - - /* - * preempt at: now + delay - */ - rq->hrtick_expire = - ktime_add_ns(rq->hrtick_timer.base->get_time(), delay); - /* - * indicate we need to program the timer - */ - __set_bit(HRTICK_SET, &rq->hrtick_flags); - if (reset) - __set_bit(HRTICK_RESET, &rq->hrtick_flags); - - /* - * New slices are called from the schedule path and don't need a - * forced reschedule. - */ - if (reset) - resched_hrt(rq->curr); -} - static void hrtick_clear(struct rq *rq) { if (hrtimer_active(&rq->hrtick_timer)) @@ -1071,32 +1018,6 @@ static void hrtick_clear(struct rq *rq) } /* - * Update the timer from the possible pending state. - */ -static void hrtick_set(struct rq *rq) -{ - ktime_t time; - int set, reset; - unsigned long flags; - - WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); - - spin_lock_irqsave(&rq->lock, flags); - set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags); - reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags); - time = rq->hrtick_expire; - clear_thread_flag(TIF_HRTICK_RESCHED); - spin_unlock_irqrestore(&rq->lock, flags); - - if (set) { - hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS); - if (reset && !hrtimer_active(&rq->hrtick_timer)) - resched_rq(rq); - } else - hrtick_clear(rq); -} - -/* * High-resolution timer tick. * Runs from hardirq context with interrupts disabled. */ @@ -1115,27 +1036,37 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer) } #ifdef CONFIG_SMP -static void hotplug_hrtick_disable(int cpu) +/* + * called from hardirq (IPI) context + */ +static void __hrtick_start(void *arg) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - rq->hrtick_flags = 0; - __set_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); + struct rq *rq = arg; - hrtick_clear(rq); + spin_lock(&rq->lock); + hrtimer_restart(&rq->hrtick_timer); + rq->hrtick_csd_pending = 0; + spin_unlock(&rq->lock); } -static void hotplug_hrtick_enable(int cpu) +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; + struct hrtimer *timer = &rq->hrtick_timer; + ktime_t time = ktime_add_ns(timer->base->get_time(), delay); - spin_lock_irqsave(&rq->lock, flags); - __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); + timer->expires = time; + + if (rq == this_rq()) { + hrtimer_restart(timer); + } else if (!rq->hrtick_csd_pending) { + __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); + rq->hrtick_csd_pending = 1; + } } static int @@ -1150,16 +1081,7 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DOWN_PREPARE_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: - hotplug_hrtick_disable(cpu); - return NOTIFY_OK; - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hotplug_hrtick_enable(cpu); + hrtick_clear(cpu_rq(cpu)); return NOTIFY_OK; } @@ -1170,46 +1092,45 @@ static void init_hrtick(void) { hotcpu_notifier(hotplug_hrtick, 0); } -#endif /* CONFIG_SMP */ +#else +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) +{ + hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); +} -static void init_rq_hrtick(struct rq *rq) +static void init_hrtick(void) { - rq->hrtick_flags = 0; - hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rq->hrtick_timer.function = hrtick; - rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; } +#endif /* CONFIG_SMP */ -void hrtick_resched(void) +static void init_rq_hrtick(struct rq *rq) { - struct rq *rq; - unsigned long flags; +#ifdef CONFIG_SMP + rq->hrtick_csd_pending = 0; - if (!test_thread_flag(TIF_HRTICK_RESCHED)) - return; + rq->hrtick_csd.flags = 0; + rq->hrtick_csd.func = __hrtick_start; + rq->hrtick_csd.info = rq; +#endif - local_irq_save(flags); - rq = cpu_rq(smp_processor_id()); - hrtick_set(rq); - local_irq_restore(flags); + hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + rq->hrtick_timer.function = hrtick; + rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; } #else static inline void hrtick_clear(struct rq *rq) { } -static inline void hrtick_set(struct rq *rq) -{ -} - static inline void init_rq_hrtick(struct rq *rq) { } -void hrtick_resched(void) -{ -} - static inline void init_hrtick(void) { } @@ -1228,16 +1149,16 @@ static inline void init_hrtick(void) #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) #endif -static void __resched_task(struct task_struct *p, int tif_bit) +static void resched_task(struct task_struct *p) { int cpu; assert_spin_locked(&task_rq(p)->lock); - if (unlikely(test_tsk_thread_flag(p, tif_bit))) + if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) return; - set_tsk_thread_flag(p, tif_bit); + set_tsk_thread_flag(p, TIF_NEED_RESCHED); cpu = task_cpu(p); if (cpu == smp_processor_id()) @@ -1303,10 +1224,10 @@ void wake_up_idle_cpu(int cpu) #endif /* CONFIG_NO_HZ */ #else /* !CONFIG_SMP */ -static void __resched_task(struct task_struct *p, int tif_bit) +static void resched_task(struct task_struct *p) { assert_spin_locked(&task_rq(p)->lock); - set_tsk_thread_flag(p, tif_bit); + set_tsk_need_resched(p); } #endif /* CONFIG_SMP */ @@ -4395,7 +4316,7 @@ asmlinkage void __sched schedule(void) struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; - int cpu, hrtick = sched_feat(HRTICK); + int cpu; need_resched: preempt_disable(); @@ -4410,7 +4331,7 @@ need_resched_nonpreemptible: schedule_debug(prev); - if (hrtick) + if (sched_feat(HRTICK)) hrtick_clear(rq); /* @@ -4457,9 +4378,6 @@ need_resched_nonpreemptible: } else spin_unlock_irq(&rq->lock); - if (hrtick) - hrtick_set(rq); - if (unlikely(reacquire_kernel_lock(current) < 0)) goto need_resched_nonpreemptible; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f2aa987027d6..6893b3ed65fe 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -878,7 +878,6 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) #ifdef CONFIG_SCHED_HRTICK static void hrtick_start_fair(struct rq *rq, struct task_struct *p) { - int requeue = rq->curr == p; struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); @@ -899,10 +898,10 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p) * Don't schedule slices shorter than 10000ns, that just * doesn't make sense. Rely on vruntime for fairness. */ - if (!requeue) + if (rq->curr != p) delta = max(10000LL, delta); - hrtick_start(rq, delta, requeue); + hrtick_start(rq, delta); } } #else /* !CONFIG_SCHED_HRTICK */ |