2 * linux/kernel/hrtimer.c
4 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
5 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
6 * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner
8 * High-resolution kernel timers
10 * In contrast to the low-resolution timeout API implemented in
11 * kernel/timer.c, hrtimers provide finer resolution and accuracy
12 * depending on system configuration and capabilities.
14 * These timers are currently used for:
18 * - precise in-kernel timing
20 * Started by: Thomas Gleixner and Ingo Molnar
23 * based on kernel/timer.c
25 * Help, testing, suggestions, bugfixes, improvements were
28 * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel
31 * For licencing details see kernel-base/COPYING
34 #include <linux/cpu.h>
35 #include <linux/module.h>
36 #include <linux/percpu.h>
37 #include <linux/hrtimer.h>
38 #include <linux/notifier.h>
39 #include <linux/syscalls.h>
40 #include <linux/kallsyms.h>
41 #include <linux/interrupt.h>
42 #include <linux/tick.h>
43 #include <linux/seq_file.h>
44 #include <linux/err.h>
45 #include <linux/debugobjects.h>
46 #include <linux/sched.h>
47 #include <linux/timer.h>
49 #include <asm/uaccess.h>
51 #include <trace/events/timer.h>
56 * Note: If we want to add new timer bases, we have to skip the two
57 * clock ids captured by the cpu-timers. We do this by holding empty
58 * entries rather than doing math adjustment of the clock ids.
59 * This ensures that we capture erroneous accesses to these clock ids
60 * rather than moving them into the range of valid clock id's.
62 DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
68 .index = CLOCK_REALTIME,
69 .get_time = &ktime_get_real,
70 .resolution = KTIME_LOW_RES,
73 .index = CLOCK_MONOTONIC,
74 .get_time = &ktime_get,
75 .resolution = KTIME_LOW_RES,
81 * Get the coarse grained time at the softirq based on xtime and
84 static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
87 struct timespec xts, tom;
91 seq = read_seqbegin(&xtime_lock);
92 xts = __current_kernel_time();
93 tom = __get_wall_to_monotonic();
94 } while (read_seqretry(&xtime_lock, seq));
96 xtim = timespec_to_ktime(xts);
97 tomono = timespec_to_ktime(tom);
98 base->clock_base[CLOCK_REALTIME].softirq_time = xtim;
99 base->clock_base[CLOCK_MONOTONIC].softirq_time =
100 ktime_add(xtim, tomono);
104 * Functions and macros which are different for UP/SMP systems are kept in a
110 * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
111 * means that all timers which are tied to this base via timer->base are
112 * locked, and the base itself is locked too.
114 * So __run_timers/migrate_timers can safely modify all timers which could
115 * be found on the lists/queues.
117 * When the timer's base is locked, and the timer removed from list, it is
118 * possible to set timer->base = NULL and drop the lock: the timer remains
122 struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
123 unsigned long *flags)
125 struct hrtimer_clock_base *base;
129 if (likely(base != NULL)) {
130 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
131 if (likely(base == timer->base))
133 /* The timer has migrated to another CPU: */
134 raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
142 * Get the preferred target CPU for NOHZ
144 static int hrtimer_get_target(int this_cpu, int pinned)
147 if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu))
148 return get_nohz_timer_target();
154 * With HIGHRES=y we do not migrate the timer when it is expiring
155 * before the next event on the target cpu because we cannot reprogram
156 * the target cpu hardware and we would cause it to fire late.
158 * Called with cpu_base->lock of target cpu held.
161 hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base)
163 #ifdef CONFIG_HIGH_RES_TIMERS
166 if (!new_base->cpu_base->hres_active)
169 expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
170 return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
177 * Switch the timer base to the current CPU when possible.
179 static inline struct hrtimer_clock_base *
180 switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
183 struct hrtimer_clock_base *new_base;
184 struct hrtimer_cpu_base *new_cpu_base;
185 int this_cpu = smp_processor_id();
186 int cpu = hrtimer_get_target(this_cpu, pinned);
189 new_cpu_base = &per_cpu(hrtimer_bases, cpu);
190 new_base = &new_cpu_base->clock_base[base->index];
192 if (base != new_base) {
194 * We are trying to move timer to new_base.
195 * However we can't change timer's base while it is running,
196 * so we keep it on the same CPU. No hassle vs. reprogramming
197 * the event source in the high resolution case. The softirq
198 * code will take care of this when the timer function has
199 * completed. There is no conflict as we hold the lock until
200 * the timer is enqueued.
202 if (unlikely(hrtimer_callback_running(timer)))
205 /* See the comment in lock_timer_base() */
207 raw_spin_unlock(&base->cpu_base->lock);
208 raw_spin_lock(&new_base->cpu_base->lock);
210 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
212 raw_spin_unlock(&new_base->cpu_base->lock);
213 raw_spin_lock(&base->cpu_base->lock);
217 timer->base = new_base;
222 #else /* CONFIG_SMP */
224 static inline struct hrtimer_clock_base *
225 lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
227 struct hrtimer_clock_base *base = timer->base;
229 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
234 # define switch_hrtimer_base(t, b, p) (b)
236 #endif /* !CONFIG_SMP */
239 * Functions for the union type storage format of ktime_t which are
240 * too large for inlining:
242 #if BITS_PER_LONG < 64
243 # ifndef CONFIG_KTIME_SCALAR
245 * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
247 * @nsec: the scalar nsec value to add
249 * Returns the sum of kt and nsec in ktime_t format
251 ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
255 if (likely(nsec < NSEC_PER_SEC)) {
258 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
260 tmp = ktime_set((long)nsec, rem);
263 return ktime_add(kt, tmp);
266 EXPORT_SYMBOL_GPL(ktime_add_ns);
269 * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable
271 * @nsec: the scalar nsec value to subtract
273 * Returns the subtraction of @nsec from @kt in ktime_t format
275 ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec)
279 if (likely(nsec < NSEC_PER_SEC)) {
282 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
284 tmp = ktime_set((long)nsec, rem);
287 return ktime_sub(kt, tmp);
290 EXPORT_SYMBOL_GPL(ktime_sub_ns);
291 # endif /* !CONFIG_KTIME_SCALAR */
294 * Divide a ktime value by a nanosecond value
296 u64 ktime_divns(const ktime_t kt, s64 div)
301 dclc = ktime_to_ns(kt);
302 /* Make sure the divisor is less than 2^32: */
308 do_div(dclc, (unsigned long) div);
312 #endif /* BITS_PER_LONG >= 64 */
315 * Add two ktime values and do a safety check for overflow:
317 ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
319 ktime_t res = ktime_add(lhs, rhs);
322 * We use KTIME_SEC_MAX here, the maximum timeout which we can
323 * return to user space in a timespec:
325 if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
326 res = ktime_set(KTIME_SEC_MAX, 0);
331 EXPORT_SYMBOL_GPL(ktime_add_safe);
333 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
335 static struct debug_obj_descr hrtimer_debug_descr;
337 static void *hrtimer_debug_hint(void *addr)
339 return ((struct hrtimer *) addr)->function;
343 * fixup_init is called when:
344 * - an active object is initialized
346 static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
348 struct hrtimer *timer = addr;
351 case ODEBUG_STATE_ACTIVE:
352 hrtimer_cancel(timer);
353 debug_object_init(timer, &hrtimer_debug_descr);
361 * fixup_activate is called when:
362 * - an active object is activated
363 * - an unknown object is activated (might be a statically initialized object)
365 static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
369 case ODEBUG_STATE_NOTAVAILABLE:
373 case ODEBUG_STATE_ACTIVE:
382 * fixup_free is called when:
383 * - an active object is freed
385 static int hrtimer_fixup_free(void *addr, enum debug_obj_state state)
387 struct hrtimer *timer = addr;
390 case ODEBUG_STATE_ACTIVE:
391 hrtimer_cancel(timer);
392 debug_object_free(timer, &hrtimer_debug_descr);
399 static struct debug_obj_descr hrtimer_debug_descr = {
401 .debug_hint = hrtimer_debug_hint,
402 .fixup_init = hrtimer_fixup_init,
403 .fixup_activate = hrtimer_fixup_activate,
404 .fixup_free = hrtimer_fixup_free,
407 static inline void debug_hrtimer_init(struct hrtimer *timer)
409 debug_object_init(timer, &hrtimer_debug_descr);
412 static inline void debug_hrtimer_activate(struct hrtimer *timer)
414 debug_object_activate(timer, &hrtimer_debug_descr);
417 static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
419 debug_object_deactivate(timer, &hrtimer_debug_descr);
422 static inline void debug_hrtimer_free(struct hrtimer *timer)
424 debug_object_free(timer, &hrtimer_debug_descr);
427 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
428 enum hrtimer_mode mode);
430 void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
431 enum hrtimer_mode mode)
433 debug_object_init_on_stack(timer, &hrtimer_debug_descr);
434 __hrtimer_init(timer, clock_id, mode);
436 EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
438 void destroy_hrtimer_on_stack(struct hrtimer *timer)
440 debug_object_free(timer, &hrtimer_debug_descr);
444 static inline void debug_hrtimer_init(struct hrtimer *timer) { }
445 static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
446 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
450 debug_init(struct hrtimer *timer, clockid_t clockid,
451 enum hrtimer_mode mode)
453 debug_hrtimer_init(timer);
454 trace_hrtimer_init(timer, clockid, mode);
457 static inline void debug_activate(struct hrtimer *timer)
459 debug_hrtimer_activate(timer);
460 trace_hrtimer_start(timer);
463 static inline void debug_deactivate(struct hrtimer *timer)
465 debug_hrtimer_deactivate(timer);
466 trace_hrtimer_cancel(timer);
469 /* High resolution timer related functions */
470 #ifdef CONFIG_HIGH_RES_TIMERS
473 * High resolution timer enabled ?
475 static int hrtimer_hres_enabled __read_mostly = 1;
478 * Enable / Disable high resolution mode
480 static int __init setup_hrtimer_hres(char *str)
482 if (!strcmp(str, "off"))
483 hrtimer_hres_enabled = 0;
484 else if (!strcmp(str, "on"))
485 hrtimer_hres_enabled = 1;
491 __setup("highres=", setup_hrtimer_hres);
494 * hrtimer_high_res_enabled - query, if the highres mode is enabled
496 static inline int hrtimer_is_hres_enabled(void)
498 return hrtimer_hres_enabled;
502 * Is the high resolution mode active ?
504 static inline int hrtimer_hres_active(void)
506 return __this_cpu_read(hrtimer_bases.hres_active);
510 * Reprogram the event source with checking both queues for the
512 * Called with interrupts disabled and base->lock held
515 hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
518 struct hrtimer_clock_base *base = cpu_base->clock_base;
519 ktime_t expires, expires_next;
521 expires_next.tv64 = KTIME_MAX;
523 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
524 struct hrtimer *timer;
525 struct timerqueue_node *next;
527 next = timerqueue_getnext(&base->active);
530 timer = container_of(next, struct hrtimer, node);
532 expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
534 * clock_was_set() has changed base->offset so the
535 * result might be negative. Fix it up to prevent a
536 * false positive in clockevents_program_event()
538 if (expires.tv64 < 0)
540 if (expires.tv64 < expires_next.tv64)
541 expires_next = expires;
544 if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
547 cpu_base->expires_next.tv64 = expires_next.tv64;
549 if (cpu_base->expires_next.tv64 != KTIME_MAX)
550 tick_program_event(cpu_base->expires_next, 1);
554 * Shared reprogramming for clock_realtime and clock_monotonic
556 * When a timer is enqueued and expires earlier than the already enqueued
557 * timers, we have to check, whether it expires earlier than the timer for
558 * which the clock event device was armed.
560 * Called with interrupts disabled and base->cpu_base.lock held
562 static int hrtimer_reprogram(struct hrtimer *timer,
563 struct hrtimer_clock_base *base)
565 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
566 ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
569 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
572 * When the callback is running, we do not reprogram the clock event
573 * device. The timer callback is either running on a different CPU or
574 * the callback is executed in the hrtimer_interrupt context. The
575 * reprogramming is handled either by the softirq, which called the
576 * callback or at the end of the hrtimer_interrupt.
578 if (hrtimer_callback_running(timer))
582 * CLOCK_REALTIME timer might be requested with an absolute
583 * expiry time which is less than base->offset. Nothing wrong
584 * about that, just avoid to call into the tick code, which
585 * has now objections against negative expiry values.
587 if (expires.tv64 < 0)
590 if (expires.tv64 >= cpu_base->expires_next.tv64)
594 * If a hang was detected in the last timer interrupt then we
595 * do not schedule a timer which is earlier than the expiry
596 * which we enforced in the hang detection. We want the system
599 if (cpu_base->hang_detected)
603 * Clockevents returns -ETIME, when the event was in the past.
605 res = tick_program_event(expires, 0);
606 if (!IS_ERR_VALUE(res))
607 cpu_base->expires_next = expires;
613 * Retrigger next event is called after clock was set
615 * Called with interrupts disabled via on_each_cpu()
617 static void retrigger_next_event(void *arg)
619 struct hrtimer_cpu_base *base;
620 struct timespec realtime_offset, wtm;
623 if (!hrtimer_hres_active())
627 seq = read_seqbegin(&xtime_lock);
628 wtm = __get_wall_to_monotonic();
629 } while (read_seqretry(&xtime_lock, seq));
630 set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);
632 base = &__get_cpu_var(hrtimer_bases);
634 /* Adjust CLOCK_REALTIME offset */
635 raw_spin_lock(&base->lock);
636 base->clock_base[CLOCK_REALTIME].offset =
637 timespec_to_ktime(realtime_offset);
639 hrtimer_force_reprogram(base, 0);
640 raw_spin_unlock(&base->lock);
644 * Clock realtime was set
646 * Change the offset of the realtime clock vs. the monotonic
649 * We might have to reprogram the high resolution timer interrupt. On
650 * SMP we call the architecture specific code to retrigger _all_ high
651 * resolution timer interrupts. On UP we just disable interrupts and
652 * call the high resolution interrupt code.
654 void clock_was_set(void)
656 /* Retrigger the CPU local events everywhere */
657 on_each_cpu(retrigger_next_event, NULL, 1);
661 * During resume we might have to reprogram the high resolution timer
662 * interrupt (on the local CPU):
664 void hres_timers_resume(void)
666 WARN_ONCE(!irqs_disabled(),
667 KERN_INFO "hres_timers_resume() called with IRQs enabled!");
669 retrigger_next_event(NULL);
673 * Initialize the high resolution related parts of cpu_base
675 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
677 base->expires_next.tv64 = KTIME_MAX;
678 base->hres_active = 0;
682 * Initialize the high resolution related parts of a hrtimer
684 static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
690 * When High resolution timers are active, try to reprogram. Note, that in case
691 * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
692 * check happens. The timer gets enqueued into the rbtree. The reprogramming
693 * and expiry check is done in the hrtimer_interrupt or in the softirq.
695 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
696 struct hrtimer_clock_base *base,
699 if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
701 raw_spin_unlock(&base->cpu_base->lock);
702 raise_softirq_irqoff(HRTIMER_SOFTIRQ);
703 raw_spin_lock(&base->cpu_base->lock);
705 __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
714 * Switch to high resolution mode
716 static int hrtimer_switch_to_hres(void)
718 int cpu = smp_processor_id();
719 struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
722 if (base->hres_active)
725 local_irq_save(flags);
727 if (tick_init_highres()) {
728 local_irq_restore(flags);
729 printk(KERN_WARNING "Could not switch to high resolution "
730 "mode on CPU %d\n", cpu);
733 base->hres_active = 1;
734 base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
735 base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
737 tick_setup_sched_timer();
739 /* "Retrigger" the interrupt to get things going */
740 retrigger_next_event(NULL);
741 local_irq_restore(flags);
747 static inline int hrtimer_hres_active(void) { return 0; }
748 static inline int hrtimer_is_hres_enabled(void) { return 0; }
749 static inline int hrtimer_switch_to_hres(void) { return 0; }
751 hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
752 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
753 struct hrtimer_clock_base *base,
758 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
759 static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
761 #endif /* CONFIG_HIGH_RES_TIMERS */
763 static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
765 #ifdef CONFIG_TIMER_STATS
766 if (timer->start_site)
768 timer->start_site = __builtin_return_address(0);
769 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
770 timer->start_pid = current->pid;
774 static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
776 #ifdef CONFIG_TIMER_STATS
777 timer->start_site = NULL;
781 static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
783 #ifdef CONFIG_TIMER_STATS
784 if (likely(!timer_stats_active))
786 timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
787 timer->function, timer->start_comm, 0);
792 * Counterpart to lock_hrtimer_base above:
795 void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
797 raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
801 * hrtimer_forward - forward the timer expiry
802 * @timer: hrtimer to forward
803 * @now: forward past this time
804 * @interval: the interval to forward
806 * Forward the timer expiry so it will expire in the future.
807 * Returns the number of overruns.
809 u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
814 delta = ktime_sub(now, hrtimer_get_expires(timer));
819 if (interval.tv64 < timer->base->resolution.tv64)
820 interval.tv64 = timer->base->resolution.tv64;
822 if (unlikely(delta.tv64 >= interval.tv64)) {
823 s64 incr = ktime_to_ns(interval);
825 orun = ktime_divns(delta, incr);
826 hrtimer_add_expires_ns(timer, incr * orun);
827 if (hrtimer_get_expires_tv64(timer) > now.tv64)
830 * This (and the ktime_add() below) is the
831 * correction for exact:
835 hrtimer_add_expires(timer, interval);
839 EXPORT_SYMBOL_GPL(hrtimer_forward);
842 * enqueue_hrtimer - internal function to (re)start a timer
844 * The timer is inserted in expiry order. Insertion into the
845 * red black tree is O(log(n)). Must hold the base lock.
847 * Returns 1 when the new timer is the leftmost timer in the tree.
849 static int enqueue_hrtimer(struct hrtimer *timer,
850 struct hrtimer_clock_base *base)
852 debug_activate(timer);
854 timerqueue_add(&base->active, &timer->node);
857 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
858 * state of a possibly running callback.
860 timer->state |= HRTIMER_STATE_ENQUEUED;
862 return (&timer->node == base->active.next);
866 * __remove_hrtimer - internal function to remove a timer
868 * Caller must hold the base lock.
870 * High resolution timer mode reprograms the clock event device when the
871 * timer is the one which expires next. The caller can disable this by setting
872 * reprogram to zero. This is useful, when the context does a reprogramming
873 * anyway (e.g. timer interrupt)
875 static void __remove_hrtimer(struct hrtimer *timer,
876 struct hrtimer_clock_base *base,
877 unsigned long newstate, int reprogram)
879 if (!(timer->state & HRTIMER_STATE_ENQUEUED))
882 if (&timer->node == timerqueue_getnext(&base->active)) {
883 #ifdef CONFIG_HIGH_RES_TIMERS
884 /* Reprogram the clock event device. if enabled */
885 if (reprogram && hrtimer_hres_active()) {
888 expires = ktime_sub(hrtimer_get_expires(timer),
890 if (base->cpu_base->expires_next.tv64 == expires.tv64)
891 hrtimer_force_reprogram(base->cpu_base, 1);
895 timerqueue_del(&base->active, &timer->node);
897 timer->state = newstate;
901 * remove hrtimer, called with base lock held
904 remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
906 if (hrtimer_is_queued(timer)) {
911 * Remove the timer and force reprogramming when high
912 * resolution mode is active and the timer is on the current
913 * CPU. If we remove a timer on another CPU, reprogramming is
914 * skipped. The interrupt event on this CPU is fired and
915 * reprogramming happens in the interrupt handler. This is a
916 * rare case and less expensive than a smp call.
918 debug_deactivate(timer);
919 timer_stats_hrtimer_clear_start_info(timer);
920 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
922 * We must preserve the CALLBACK state flag here,
923 * otherwise we could move the timer base in
924 * switch_hrtimer_base.
926 state = timer->state & HRTIMER_STATE_CALLBACK;
927 __remove_hrtimer(timer, base, state, reprogram);
933 int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
934 unsigned long delta_ns, const enum hrtimer_mode mode,
937 struct hrtimer_clock_base *base, *new_base;
941 base = lock_hrtimer_base(timer, &flags);
943 /* Remove an active timer from the queue: */
944 ret = remove_hrtimer(timer, base);
946 /* Switch the timer base, if necessary: */
947 new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
949 if (mode & HRTIMER_MODE_REL) {
950 tim = ktime_add_safe(tim, new_base->get_time());
952 * CONFIG_TIME_LOW_RES is a temporary way for architectures
953 * to signal that they simply return xtime in
954 * do_gettimeoffset(). In this case we want to round up by
955 * resolution when starting a relative timer, to avoid short
956 * timeouts. This will go away with the GTOD framework.
958 #ifdef CONFIG_TIME_LOW_RES
959 tim = ktime_add_safe(tim, base->resolution);
963 hrtimer_set_expires_range_ns(timer, tim, delta_ns);
965 timer_stats_hrtimer_set_start_info(timer);
967 leftmost = enqueue_hrtimer(timer, new_base);
970 * Only allow reprogramming if the new base is on this CPU.
971 * (it might still be on another CPU if the timer was pending)
973 * XXX send_remote_softirq() ?
975 if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
976 hrtimer_enqueue_reprogram(timer, new_base, wakeup);
978 unlock_hrtimer_base(timer, &flags);
984 * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
985 * @timer: the timer to be added
987 * @delta_ns: "slack" range for the timer
988 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
992 * 1 when the timer was active
994 int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
995 unsigned long delta_ns, const enum hrtimer_mode mode)
997 return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1);
999 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
1002 * hrtimer_start - (re)start an hrtimer on the current CPU
1003 * @timer: the timer to be added
1005 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
1009 * 1 when the timer was active
1012 hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
1014 return __hrtimer_start_range_ns(timer, tim, 0, mode, 1);
1016 EXPORT_SYMBOL_GPL(hrtimer_start);
1020 * hrtimer_try_to_cancel - try to deactivate a timer
1021 * @timer: hrtimer to stop
1024 * 0 when the timer was not active
1025 * 1 when the timer was active
1026 * -1 when the timer is currently excuting the callback function and
1029 int hrtimer_try_to_cancel(struct hrtimer *timer)
1031 struct hrtimer_clock_base *base;
1032 unsigned long flags;
1035 base = lock_hrtimer_base(timer, &flags);
1037 if (!hrtimer_callback_running(timer))
1038 ret = remove_hrtimer(timer, base);
1040 unlock_hrtimer_base(timer, &flags);
1045 EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
1048 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
1049 * @timer: the timer to be cancelled
1052 * 0 when the timer was not active
1053 * 1 when the timer was active
1055 int hrtimer_cancel(struct hrtimer *timer)
1058 int ret = hrtimer_try_to_cancel(timer);
1065 EXPORT_SYMBOL_GPL(hrtimer_cancel);
1068 * hrtimer_get_remaining - get remaining time for the timer
1069 * @timer: the timer to read
1071 ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
1073 unsigned long flags;
1076 lock_hrtimer_base(timer, &flags);
1077 rem = hrtimer_expires_remaining(timer);
1078 unlock_hrtimer_base(timer, &flags);
1082 EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
1086 * hrtimer_get_next_event - get the time until next expiry event
1088 * Returns the delta to the next expiry event or KTIME_MAX if no timer
1091 ktime_t hrtimer_get_next_event(void)
1093 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1094 struct hrtimer_clock_base *base = cpu_base->clock_base;
1095 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
1096 unsigned long flags;
1099 raw_spin_lock_irqsave(&cpu_base->lock, flags);
1101 if (!hrtimer_hres_active()) {
1102 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
1103 struct hrtimer *timer;
1104 struct timerqueue_node *next;
1106 next = timerqueue_getnext(&base->active);
1110 timer = container_of(next, struct hrtimer, node);
1111 delta.tv64 = hrtimer_get_expires_tv64(timer);
1112 delta = ktime_sub(delta, base->get_time());
1113 if (delta.tv64 < mindelta.tv64)
1114 mindelta.tv64 = delta.tv64;
1118 raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
1120 if (mindelta.tv64 < 0)
1126 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1127 enum hrtimer_mode mode)
1129 struct hrtimer_cpu_base *cpu_base;
1131 memset(timer, 0, sizeof(struct hrtimer));
1133 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1135 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
1136 clock_id = CLOCK_MONOTONIC;
1138 timer->base = &cpu_base->clock_base[clock_id];
1139 hrtimer_init_timer_hres(timer);
1140 timerqueue_init(&timer->node);
1142 #ifdef CONFIG_TIMER_STATS
1143 timer->start_site = NULL;
1144 timer->start_pid = -1;
1145 memset(timer->start_comm, 0, TASK_COMM_LEN);
1150 * hrtimer_init - initialize a timer to the given clock
1151 * @timer: the timer to be initialized
1152 * @clock_id: the clock to be used
1153 * @mode: timer mode abs/rel
1155 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1156 enum hrtimer_mode mode)
1158 debug_init(timer, clock_id, mode);
1159 __hrtimer_init(timer, clock_id, mode);
1161 EXPORT_SYMBOL_GPL(hrtimer_init);
1164 * hrtimer_get_res - get the timer resolution for a clock
1165 * @which_clock: which clock to query
1166 * @tp: pointer to timespec variable to store the resolution
1168 * Store the resolution of the clock selected by @which_clock in the
1169 * variable pointed to by @tp.
1171 int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1173 struct hrtimer_cpu_base *cpu_base;
1175 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1176 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
1180 EXPORT_SYMBOL_GPL(hrtimer_get_res);
1182 static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
1184 struct hrtimer_clock_base *base = timer->base;
1185 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1186 enum hrtimer_restart (*fn)(struct hrtimer *);
1189 WARN_ON(!irqs_disabled());
1191 debug_deactivate(timer);
1192 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1193 timer_stats_account_hrtimer(timer);
1194 fn = timer->function;
1197 * Because we run timers from hardirq context, there is no chance
1198 * they get migrated to another cpu, therefore its safe to unlock
1201 raw_spin_unlock(&cpu_base->lock);
1202 trace_hrtimer_expire_entry(timer, now);
1203 restart = fn(timer);
1204 trace_hrtimer_expire_exit(timer);
1205 raw_spin_lock(&cpu_base->lock);
1208 * Note: We clear the CALLBACK bit after enqueue_hrtimer and
1209 * we do not reprogramm the event hardware. Happens either in
1210 * hrtimer_start_range_ns() or in hrtimer_interrupt()
1212 if (restart != HRTIMER_NORESTART) {
1213 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1214 enqueue_hrtimer(timer, base);
1217 WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK));
1219 timer->state &= ~HRTIMER_STATE_CALLBACK;
1222 #ifdef CONFIG_HIGH_RES_TIMERS
1225 * High resolution timer interrupt
1226 * Called with interrupts disabled
1228 void hrtimer_interrupt(struct clock_event_device *dev)
1230 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1231 struct hrtimer_clock_base *base;
1232 ktime_t expires_next, now, entry_time, delta;
1235 BUG_ON(!cpu_base->hres_active);
1236 cpu_base->nr_events++;
1237 dev->next_event.tv64 = KTIME_MAX;
1239 entry_time = now = ktime_get();
1241 expires_next.tv64 = KTIME_MAX;
1243 raw_spin_lock(&cpu_base->lock);
1245 * We set expires_next to KTIME_MAX here with cpu_base->lock
1246 * held to prevent that a timer is enqueued in our queue via
1247 * the migration code. This does not affect enqueueing of
1248 * timers which run their callback and need to be requeued on
1251 cpu_base->expires_next.tv64 = KTIME_MAX;
1253 base = cpu_base->clock_base;
1255 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1257 struct timerqueue_node *node;
1259 basenow = ktime_add(now, base->offset);
1261 while ((node = timerqueue_getnext(&base->active))) {
1262 struct hrtimer *timer;
1264 timer = container_of(node, struct hrtimer, node);
1267 * The immediate goal for using the softexpires is
1268 * minimizing wakeups, not running timers at the
1269 * earliest interrupt after their soft expiration.
1270 * This allows us to avoid using a Priority Search
1271 * Tree, which can answer a stabbing querry for
1272 * overlapping intervals and instead use the simple
1273 * BST we already have.
1274 * We don't add extra wakeups by delaying timers that
1275 * are right-of a not yet expired timer, because that
1276 * timer will have to trigger a wakeup anyway.
1279 if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
1282 expires = ktime_sub(hrtimer_get_expires(timer),
1284 if (expires.tv64 < expires_next.tv64)
1285 expires_next = expires;
1289 __run_hrtimer(timer, &basenow);
1295 * Store the new expiry value so the migration code can verify
1298 cpu_base->expires_next = expires_next;
1299 raw_spin_unlock(&cpu_base->lock);
1301 /* Reprogramming necessary ? */
1302 if (expires_next.tv64 == KTIME_MAX ||
1303 !tick_program_event(expires_next, 0)) {
1304 cpu_base->hang_detected = 0;
1309 * The next timer was already expired due to:
1311 * - long lasting callbacks
1312 * - being scheduled away when running in a VM
1314 * We need to prevent that we loop forever in the hrtimer
1315 * interrupt routine. We give it 3 attempts to avoid
1316 * overreacting on some spurious event.
1319 cpu_base->nr_retries++;
1323 * Give the system a chance to do something else than looping
1324 * here. We stored the entry time, so we know exactly how long
1325 * we spent here. We schedule the next event this amount of
1328 cpu_base->nr_hangs++;
1329 cpu_base->hang_detected = 1;
1330 delta = ktime_sub(now, entry_time);
1331 if (delta.tv64 > cpu_base->max_hang_time.tv64)
1332 cpu_base->max_hang_time = delta;
1334 * Limit it to a sensible value as we enforce a longer
1335 * delay. Give the CPU at least 100ms to catch up.
1337 if (delta.tv64 > 100 * NSEC_PER_MSEC)
1338 expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC);
1340 expires_next = ktime_add(now, delta);
1341 tick_program_event(expires_next, 1);
1342 printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
1343 ktime_to_ns(delta));
1347 * local version of hrtimer_peek_ahead_timers() called with interrupts
1350 static void __hrtimer_peek_ahead_timers(void)
1352 struct tick_device *td;
1354 if (!hrtimer_hres_active())
1357 td = &__get_cpu_var(tick_cpu_device);
1358 if (td && td->evtdev)
1359 hrtimer_interrupt(td->evtdev);
1363 * hrtimer_peek_ahead_timers -- run soft-expired timers now
1365 * hrtimer_peek_ahead_timers will peek at the timer queue of
1366 * the current cpu and check if there are any timers for which
1367 * the soft expires time has passed. If any such timers exist,
1368 * they are run immediately and then removed from the timer queue.
1371 void hrtimer_peek_ahead_timers(void)
1373 unsigned long flags;
1375 local_irq_save(flags);
1376 __hrtimer_peek_ahead_timers();
1377 local_irq_restore(flags);
1380 static void run_hrtimer_softirq(struct softirq_action *h)
1382 hrtimer_peek_ahead_timers();
1385 #else /* CONFIG_HIGH_RES_TIMERS */
1387 static inline void __hrtimer_peek_ahead_timers(void) { }
1389 #endif /* !CONFIG_HIGH_RES_TIMERS */
1392 * Called from timer softirq every jiffy, expire hrtimers:
1394 * For HRT its the fall back code to run the softirq in the timer
1395 * softirq context in case the hrtimer initialization failed or has
1396 * not been done yet.
1398 void hrtimer_run_pending(void)
1400 if (hrtimer_hres_active())
1404 * This _is_ ugly: We have to check in the softirq context,
1405 * whether we can switch to highres and / or nohz mode. The
1406 * clocksource switch happens in the timer interrupt with
1407 * xtime_lock held. Notification from there only sets the
1408 * check bit in the tick_oneshot code, otherwise we might
1409 * deadlock vs. xtime_lock.
1411 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1412 hrtimer_switch_to_hres();
1416 * Called from hardirq context every jiffy
1418 void hrtimer_run_queues(void)
1420 struct timerqueue_node *node;
1421 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1422 struct hrtimer_clock_base *base;
1423 int index, gettime = 1;
1425 if (hrtimer_hres_active())
1428 for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
1429 base = &cpu_base->clock_base[index];
1430 if (!timerqueue_getnext(&base->active))
1434 hrtimer_get_softirq_time(cpu_base);
1438 raw_spin_lock(&cpu_base->lock);
1440 while ((node = timerqueue_getnext(&base->active))) {
1441 struct hrtimer *timer;
1443 timer = container_of(node, struct hrtimer, node);
1444 if (base->softirq_time.tv64 <=
1445 hrtimer_get_expires_tv64(timer))
1448 __run_hrtimer(timer, &base->softirq_time);
1450 raw_spin_unlock(&cpu_base->lock);
1455 * Sleep related functions:
1457 static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
1459 struct hrtimer_sleeper *t =
1460 container_of(timer, struct hrtimer_sleeper, timer);
1461 struct task_struct *task = t->task;
1465 wake_up_process(task);
1467 return HRTIMER_NORESTART;
1470 void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
1472 sl->timer.function = hrtimer_wakeup;
1475 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
1477 static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
1479 hrtimer_init_sleeper(t, current);
1482 set_current_state(TASK_INTERRUPTIBLE);
1483 hrtimer_start_expires(&t->timer, mode);
1484 if (!hrtimer_active(&t->timer))
1487 if (likely(t->task))
1490 hrtimer_cancel(&t->timer);
1491 mode = HRTIMER_MODE_ABS;
1493 } while (t->task && !signal_pending(current));
1495 __set_current_state(TASK_RUNNING);
1497 return t->task == NULL;
1500 static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
1502 struct timespec rmt;
1505 rem = hrtimer_expires_remaining(timer);
1508 rmt = ktime_to_timespec(rem);
1510 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1516 long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1518 struct hrtimer_sleeper t;
1519 struct timespec __user *rmtp;
1522 hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
1524 hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
1526 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1529 rmtp = restart->nanosleep.rmtp;
1531 ret = update_rmtp(&t.timer, rmtp);
1536 /* The other values in restart are already filled in */
1537 ret = -ERESTART_RESTARTBLOCK;
1539 destroy_hrtimer_on_stack(&t.timer);
1543 long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1544 const enum hrtimer_mode mode, const clockid_t clockid)
1546 struct restart_block *restart;
1547 struct hrtimer_sleeper t;
1549 unsigned long slack;
1551 slack = current->timer_slack_ns;
1552 if (rt_task(current))
1555 hrtimer_init_on_stack(&t.timer, clockid, mode);
1556 hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1557 if (do_nanosleep(&t, mode))
1560 /* Absolute timers do not update the rmtp value and restart: */
1561 if (mode == HRTIMER_MODE_ABS) {
1562 ret = -ERESTARTNOHAND;
1567 ret = update_rmtp(&t.timer, rmtp);
1572 restart = ¤t_thread_info()->restart_block;
1573 restart->fn = hrtimer_nanosleep_restart;
1574 restart->nanosleep.index = t.timer.base->index;
1575 restart->nanosleep.rmtp = rmtp;
1576 restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
1578 ret = -ERESTART_RESTARTBLOCK;
1580 destroy_hrtimer_on_stack(&t.timer);
1584 SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
1585 struct timespec __user *, rmtp)
1589 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1592 if (!timespec_valid(&tu))
1595 return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
1599 * Functions related to boot-time initialization:
1601 static void __cpuinit init_hrtimers_cpu(int cpu)
1603 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
1606 raw_spin_lock_init(&cpu_base->lock);
1608 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1609 cpu_base->clock_base[i].cpu_base = cpu_base;
1610 timerqueue_init_head(&cpu_base->clock_base[i].active);
1613 hrtimer_init_hres(cpu_base);
1616 #ifdef CONFIG_HOTPLUG_CPU
1618 static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1619 struct hrtimer_clock_base *new_base)
1621 struct hrtimer *timer;
1622 struct timerqueue_node *node;
1624 while ((node = timerqueue_getnext(&old_base->active))) {
1625 timer = container_of(node, struct hrtimer, node);
1626 BUG_ON(hrtimer_callback_running(timer));
1627 debug_deactivate(timer);
1630 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
1631 * timer could be seen as !active and just vanish away
1632 * under us on another CPU
1634 __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
1635 timer->base = new_base;
1637 * Enqueue the timers on the new cpu. This does not
1638 * reprogram the event device in case the timer
1639 * expires before the earliest on this CPU, but we run
1640 * hrtimer_interrupt after we migrated everything to
1641 * sort out already expired timers and reprogram the
1644 enqueue_hrtimer(timer, new_base);
1646 /* Clear the migration state bit */
1647 timer->state &= ~HRTIMER_STATE_MIGRATE;
1651 static void migrate_hrtimers(int scpu)
1653 struct hrtimer_cpu_base *old_base, *new_base;
1656 BUG_ON(cpu_online(scpu));
1657 tick_cancel_sched_timer(scpu);
1659 local_irq_disable();
1660 old_base = &per_cpu(hrtimer_bases, scpu);
1661 new_base = &__get_cpu_var(hrtimer_bases);
1663 * The caller is globally serialized and nobody else
1664 * takes two locks at once, deadlock is not possible.
1666 raw_spin_lock(&new_base->lock);
1667 raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1669 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1670 migrate_hrtimer_list(&old_base->clock_base[i],
1671 &new_base->clock_base[i]);
1674 raw_spin_unlock(&old_base->lock);
1675 raw_spin_unlock(&new_base->lock);
1677 /* Check, if we got expired work to do */
1678 __hrtimer_peek_ahead_timers();
1682 #endif /* CONFIG_HOTPLUG_CPU */
1684 static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
1685 unsigned long action, void *hcpu)
1687 int scpu = (long)hcpu;
1691 case CPU_UP_PREPARE:
1692 case CPU_UP_PREPARE_FROZEN:
1693 init_hrtimers_cpu(scpu);
1696 #ifdef CONFIG_HOTPLUG_CPU
1698 case CPU_DYING_FROZEN:
1699 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu);
1702 case CPU_DEAD_FROZEN:
1704 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu);
1705 migrate_hrtimers(scpu);
1717 static struct notifier_block __cpuinitdata hrtimers_nb = {
1718 .notifier_call = hrtimer_cpu_notify,
1721 void __init hrtimers_init(void)
1723 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1724 (void *)(long)smp_processor_id());
1725 register_cpu_notifier(&hrtimers_nb);
1726 #ifdef CONFIG_HIGH_RES_TIMERS
1727 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
1732 * schedule_hrtimeout_range_clock - sleep until timeout
1733 * @expires: timeout value (ktime_t)
1734 * @delta: slack in expires timeout (ktime_t)
1735 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1736 * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME
1739 schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
1740 const enum hrtimer_mode mode, int clock)
1742 struct hrtimer_sleeper t;
1745 * Optimize when a zero timeout value is given. It does not
1746 * matter whether this is an absolute or a relative time.
1748 if (expires && !expires->tv64) {
1749 __set_current_state(TASK_RUNNING);
1754 * A NULL parameter means "infinite"
1758 __set_current_state(TASK_RUNNING);
1762 hrtimer_init_on_stack(&t.timer, clock, mode);
1763 hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
1765 hrtimer_init_sleeper(&t, current);
1767 hrtimer_start_expires(&t.timer, mode);
1768 if (!hrtimer_active(&t.timer))
1774 hrtimer_cancel(&t.timer);
1775 destroy_hrtimer_on_stack(&t.timer);
1777 __set_current_state(TASK_RUNNING);
1779 return !t.task ? 0 : -EINTR;
1783 * schedule_hrtimeout_range - sleep until timeout
1784 * @expires: timeout value (ktime_t)
1785 * @delta: slack in expires timeout (ktime_t)
1786 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1788 * Make the current task sleep until the given expiry time has
1789 * elapsed. The routine will return immediately unless
1790 * the current task state has been set (see set_current_state()).
1792 * The @delta argument gives the kernel the freedom to schedule the
1793 * actual wakeup to a time that is both power and performance friendly.
1794 * The kernel give the normal best effort behavior for "@expires+@delta",
1795 * but may decide to fire the timer earlier, but no earlier than @expires.
1797 * You can set the task state as follows -
1799 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1800 * pass before the routine returns.
1802 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1803 * delivered to the current task.
1805 * The current task state is guaranteed to be TASK_RUNNING when this
1808 * Returns 0 when the timer has expired otherwise -EINTR
1810 int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
1811 const enum hrtimer_mode mode)
1813 return schedule_hrtimeout_range_clock(expires, delta, mode,
1816 EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
1819 * schedule_hrtimeout - sleep until timeout
1820 * @expires: timeout value (ktime_t)
1821 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1823 * Make the current task sleep until the given expiry time has
1824 * elapsed. The routine will return immediately unless
1825 * the current task state has been set (see set_current_state()).
1827 * You can set the task state as follows -
1829 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1830 * pass before the routine returns.
1832 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1833 * delivered to the current task.
1835 * The current task state is guaranteed to be TASK_RUNNING when this
1838 * Returns 0 when the timer has expired otherwise -EINTR
1840 int __sched schedule_hrtimeout(ktime_t *expires,
1841 const enum hrtimer_mode mode)
1843 return schedule_hrtimeout_range(expires, 0, mode);
1845 EXPORT_SYMBOL_GPL(schedule_hrtimeout);