diff options
Diffstat (limited to 'kernel/time/hrtimer.c')
| -rw-r--r-- | kernel/time/hrtimer.c | 145 |
1 files changed, 132 insertions, 13 deletions
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 3e93c54bd3a1..1ea0244fc32f 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -730,6 +730,29 @@ static void hrtimer_switch_to_hres(void) retrigger_next_event(NULL); } +#ifdef CONFIG_PREEMPT_RT_FULL + +static struct swork_event clock_set_delay_work; + +static void run_clock_set_delay(struct swork_event *event) +{ + clock_was_set(); +} + +void clock_was_set_delayed(void) +{ + swork_queue(&clock_set_delay_work); +} + +static __init int create_clock_set_delay_thread(void) +{ + WARN_ON(swork_get()); + INIT_SWORK(&clock_set_delay_work, run_clock_set_delay); + return 0; +} +early_initcall(create_clock_set_delay_thread); +#else /* PREEMPT_RT_FULL */ + static void clock_was_set_work(struct work_struct *work) { clock_was_set(); @@ -745,6 +768,7 @@ void clock_was_set_delayed(void) { schedule_work(&hrtimer_work); } +#endif #else @@ -939,6 +963,33 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) } EXPORT_SYMBOL_GPL(hrtimer_forward); +#ifdef CONFIG_PREEMPT_RT_BASE +# define wake_up_timer_waiters(b) wake_up(&(b)->wait) + +/** + * hrtimer_wait_for_timer - Wait for a running timer + * + * @timer: timer to wait for + * + * The function waits in case the timers callback function is + * currently executed on the waitqueue of the timer base. The + * waitqueue is woken up after the timer callback function has + * finished execution. + */ +void hrtimer_wait_for_timer(const struct hrtimer *timer) +{ + struct hrtimer_clock_base *base = timer->base; + + if (base && base->cpu_base && + base->index >= HRTIMER_BASE_MONOTONIC_SOFT) + wait_event(base->cpu_base->wait, + !(hrtimer_callback_running(timer))); +} + +#else +# define wake_up_timer_waiters(b) do { } while (0) +#endif + /* * enqueue_hrtimer - internal function to (re)start a timer * @@ -1108,7 +1159,9 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft * match. */ +#ifndef CONFIG_PREEMPT_RT_BASE WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft); +#endif base = lock_hrtimer_base(timer, &flags); @@ -1171,7 +1224,7 @@ int hrtimer_cancel(struct hrtimer *timer) if (ret >= 0) return ret; - cpu_relax(); + hrtimer_wait_for_timer(timer); } } EXPORT_SYMBOL_GPL(hrtimer_cancel); @@ -1268,10 +1321,17 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id) static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode) { - bool softtimer = !!(mode & HRTIMER_MODE_SOFT); - int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; + bool softtimer; + int base; struct hrtimer_cpu_base *cpu_base; + softtimer = !!(mode & HRTIMER_MODE_SOFT); +#ifdef CONFIG_PREEMPT_RT_FULL + if (!softtimer && !(mode & HRTIMER_MODE_HARD)) + softtimer = true; +#endif + base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; + memset(timer, 0, sizeof(struct hrtimer)); cpu_base = raw_cpu_ptr(&hrtimer_bases); @@ -1477,6 +1537,7 @@ static __latent_entropy void hrtimer_run_softirq(struct softirq_action *h) hrtimer_update_softirq_timer(cpu_base, true); raw_spin_unlock_irqrestore(&cpu_base->lock, flags); + wake_up_timer_waiters(cpu_base); } #ifdef CONFIG_HIGH_RES_TIMERS @@ -1649,13 +1710,52 @@ static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) return HRTIMER_NORESTART; } -void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) +static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task) { +#ifdef CONFIG_PREEMPT_RT_FULL + if (!(mode & (HRTIMER_MODE_SOFT | HRTIMER_MODE_HARD))) { + if (task_is_realtime(current) || system_state != SYSTEM_RUNNING) + mode |= HRTIMER_MODE_HARD; + else + mode |= HRTIMER_MODE_SOFT; + } +#endif + __hrtimer_init(&sl->timer, clock_id, mode); sl->timer.function = hrtimer_wakeup; sl->task = task; } + +/** + * hrtimer_init_sleeper - initialize sleeper to the given clock + * @sl: sleeper to be initialized + * @clock_id: the clock to be used + * @mode: timer mode abs/rel + * @task: the task to wake up + */ +void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode, struct task_struct *task) +{ + debug_init(&sl->timer, clock_id, mode); + __hrtimer_init_sleeper(sl, clock_id, mode, task); + +} EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS +void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task) +{ + debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr); + __hrtimer_init_sleeper(sl, clock_id, mode, task); +} +EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack); +#endif + int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts) { switch(restart->nanosleep.type) { @@ -1679,8 +1779,6 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod { struct restart_block *restart; - hrtimer_init_sleeper(t, current); - do { set_current_state(TASK_INTERRUPTIBLE); hrtimer_start_expires(&t->timer, mode); @@ -1717,10 +1815,9 @@ static long __sched hrtimer_nanosleep_restart(struct restart_block *restart) struct hrtimer_sleeper t; int ret; - hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, - HRTIMER_MODE_ABS); + hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid, + HRTIMER_MODE_ABS, current); hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); - ret = do_nanosleep(&t, HRTIMER_MODE_ABS); destroy_hrtimer_on_stack(&t.timer); return ret; @@ -1738,7 +1835,7 @@ long hrtimer_nanosleep(const struct timespec64 *rqtp, if (dl_task(current) || rt_task(current)) slack = 0; - hrtimer_init_on_stack(&t.timer, clockid, mode); + hrtimer_init_sleeper_on_stack(&t, clockid, mode, current); hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack); ret = do_nanosleep(&t, mode); if (ret != -ERESTART_RESTARTBLOCK) @@ -1798,6 +1895,27 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp, } #endif +#ifdef CONFIG_PREEMPT_RT_FULL +/* + * Sleep for 1 ms in hope whoever holds what we want will let it go. + */ +void cpu_chill(void) +{ + ktime_t chill_time; + unsigned int freeze_flag = current->flags & PF_NOFREEZE; + + chill_time = ktime_set(0, NSEC_PER_MSEC); + set_current_state(TASK_UNINTERRUPTIBLE); + current->flags |= PF_NOFREEZE; + sleeping_lock_inc(); + schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD); + sleeping_lock_dec(); + if (!freeze_flag) + current->flags &= ~PF_NOFREEZE; +} +EXPORT_SYMBOL(cpu_chill); +#endif + /* * Functions related to boot-time initialization: */ @@ -1819,6 +1937,9 @@ int hrtimers_prepare_cpu(unsigned int cpu) cpu_base->softirq_next_timer = NULL; cpu_base->expires_next = KTIME_MAX; cpu_base->softirq_expires_next = KTIME_MAX; +#ifdef CONFIG_PREEMPT_RT_BASE + init_waitqueue_head(&cpu_base->wait); +#endif return 0; } @@ -1937,11 +2058,9 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, return -EINTR; } - hrtimer_init_on_stack(&t.timer, clock_id, mode); + hrtimer_init_sleeper_on_stack(&t, clock_id, mode, current); hrtimer_set_expires_range_ns(&t.timer, *expires, delta); - hrtimer_init_sleeper(&t, current); - hrtimer_start_expires(&t.timer, mode); if (likely(t.task)) |