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 = 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 spin_lock_irqsave(&base->cpu_base->lock, *flags);
131 if (likely(base == timer->base))
133 /* The timer has migrated to another CPU: */
134 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 int preferred_cpu = get_nohz_load_balancer();
150 if (preferred_cpu >= 0)
151 return preferred_cpu;
158 * With HIGHRES=y we do not migrate the timer when it is expiring
159 * before the next event on the target cpu because we cannot reprogram
160 * the target cpu hardware and we would cause it to fire late.
162 * Called with cpu_base->lock of target cpu held.
165 hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base)
167 #ifdef CONFIG_HIGH_RES_TIMERS
170 if (!new_base->cpu_base->hres_active)
173 expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
174 return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
181 * Switch the timer base to the current CPU when possible.
183 static inline struct hrtimer_clock_base *
184 switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
187 struct hrtimer_clock_base *new_base;
188 struct hrtimer_cpu_base *new_cpu_base;
189 int this_cpu = smp_processor_id();
190 int cpu = hrtimer_get_target(this_cpu, pinned);
193 new_cpu_base = &per_cpu(hrtimer_bases, cpu);
194 new_base = &new_cpu_base->clock_base[base->index];
196 if (base != new_base) {
198 * We are trying to move timer to new_base.
199 * However we can't change timer's base while it is running,
200 * so we keep it on the same CPU. No hassle vs. reprogramming
201 * the event source in the high resolution case. The softirq
202 * code will take care of this when the timer function has
203 * completed. There is no conflict as we hold the lock until
204 * the timer is enqueued.
206 if (unlikely(hrtimer_callback_running(timer)))
209 /* See the comment in lock_timer_base() */
211 spin_unlock(&base->cpu_base->lock);
212 spin_lock(&new_base->cpu_base->lock);
214 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
216 spin_unlock(&new_base->cpu_base->lock);
217 spin_lock(&base->cpu_base->lock);
221 timer->base = new_base;
226 #else /* CONFIG_SMP */
228 static inline struct hrtimer_clock_base *
229 lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
231 struct hrtimer_clock_base *base = timer->base;
233 spin_lock_irqsave(&base->cpu_base->lock, *flags);
238 # define switch_hrtimer_base(t, b, p) (b)
240 #endif /* !CONFIG_SMP */
243 * Functions for the union type storage format of ktime_t which are
244 * too large for inlining:
246 #if BITS_PER_LONG < 64
247 # ifndef CONFIG_KTIME_SCALAR
249 * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
251 * @nsec: the scalar nsec value to add
253 * Returns the sum of kt and nsec in ktime_t format
255 ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
259 if (likely(nsec < NSEC_PER_SEC)) {
262 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
264 tmp = ktime_set((long)nsec, rem);
267 return ktime_add(kt, tmp);
270 EXPORT_SYMBOL_GPL(ktime_add_ns);
273 * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable
275 * @nsec: the scalar nsec value to subtract
277 * Returns the subtraction of @nsec from @kt in ktime_t format
279 ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec)
283 if (likely(nsec < NSEC_PER_SEC)) {
286 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
288 tmp = ktime_set((long)nsec, rem);
291 return ktime_sub(kt, tmp);
294 EXPORT_SYMBOL_GPL(ktime_sub_ns);
295 # endif /* !CONFIG_KTIME_SCALAR */
298 * Divide a ktime value by a nanosecond value
300 u64 ktime_divns(const ktime_t kt, s64 div)
305 dclc = ktime_to_ns(kt);
306 /* Make sure the divisor is less than 2^32: */
312 do_div(dclc, (unsigned long) div);
316 #endif /* BITS_PER_LONG >= 64 */
319 * Add two ktime values and do a safety check for overflow:
321 ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
323 ktime_t res = ktime_add(lhs, rhs);
326 * We use KTIME_SEC_MAX here, the maximum timeout which we can
327 * return to user space in a timespec:
329 if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
330 res = ktime_set(KTIME_SEC_MAX, 0);
335 EXPORT_SYMBOL_GPL(ktime_add_safe);
337 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
339 static struct debug_obj_descr hrtimer_debug_descr;
342 * fixup_init is called when:
343 * - an active object is initialized
345 static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
347 struct hrtimer *timer = addr;
350 case ODEBUG_STATE_ACTIVE:
351 hrtimer_cancel(timer);
352 debug_object_init(timer, &hrtimer_debug_descr);
360 * fixup_activate is called when:
361 * - an active object is activated
362 * - an unknown object is activated (might be a statically initialized object)
364 static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
368 case ODEBUG_STATE_NOTAVAILABLE:
372 case ODEBUG_STATE_ACTIVE:
381 * fixup_free is called when:
382 * - an active object is freed
384 static int hrtimer_fixup_free(void *addr, enum debug_obj_state state)
386 struct hrtimer *timer = addr;
389 case ODEBUG_STATE_ACTIVE:
390 hrtimer_cancel(timer);
391 debug_object_free(timer, &hrtimer_debug_descr);
398 static struct debug_obj_descr hrtimer_debug_descr = {
400 .fixup_init = hrtimer_fixup_init,
401 .fixup_activate = hrtimer_fixup_activate,
402 .fixup_free = hrtimer_fixup_free,
405 static inline void debug_hrtimer_init(struct hrtimer *timer)
407 debug_object_init(timer, &hrtimer_debug_descr);
410 static inline void debug_hrtimer_activate(struct hrtimer *timer)
412 debug_object_activate(timer, &hrtimer_debug_descr);
415 static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
417 debug_object_deactivate(timer, &hrtimer_debug_descr);
420 static inline void debug_hrtimer_free(struct hrtimer *timer)
422 debug_object_free(timer, &hrtimer_debug_descr);
425 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
426 enum hrtimer_mode mode);
428 void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
429 enum hrtimer_mode mode)
431 debug_object_init_on_stack(timer, &hrtimer_debug_descr);
432 __hrtimer_init(timer, clock_id, mode);
434 EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
436 void destroy_hrtimer_on_stack(struct hrtimer *timer)
438 debug_object_free(timer, &hrtimer_debug_descr);
442 static inline void debug_hrtimer_init(struct hrtimer *timer) { }
443 static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
444 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
448 debug_init(struct hrtimer *timer, clockid_t clockid,
449 enum hrtimer_mode mode)
451 debug_hrtimer_init(timer);
452 trace_hrtimer_init(timer, clockid, mode);
455 static inline void debug_activate(struct hrtimer *timer)
457 debug_hrtimer_activate(timer);
458 trace_hrtimer_start(timer);
461 static inline void debug_deactivate(struct hrtimer *timer)
463 debug_hrtimer_deactivate(timer);
464 trace_hrtimer_cancel(timer);
467 /* High resolution timer related functions */
468 #ifdef CONFIG_HIGH_RES_TIMERS
471 * High resolution timer enabled ?
473 static int hrtimer_hres_enabled __read_mostly = 1;
476 * Enable / Disable high resolution mode
478 static int __init setup_hrtimer_hres(char *str)
480 if (!strcmp(str, "off"))
481 hrtimer_hres_enabled = 0;
482 else if (!strcmp(str, "on"))
483 hrtimer_hres_enabled = 1;
489 __setup("highres=", setup_hrtimer_hres);
492 * hrtimer_high_res_enabled - query, if the highres mode is enabled
494 static inline int hrtimer_is_hres_enabled(void)
496 return hrtimer_hres_enabled;
500 * Is the high resolution mode active ?
502 static inline int hrtimer_hres_active(void)
504 return __get_cpu_var(hrtimer_bases).hres_active;
508 * Reprogram the event source with checking both queues for the
510 * Called with interrupts disabled and base->lock held
513 hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
516 struct hrtimer_clock_base *base = cpu_base->clock_base;
517 ktime_t expires, expires_next;
519 expires_next.tv64 = KTIME_MAX;
521 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
522 struct hrtimer *timer;
526 timer = rb_entry(base->first, struct hrtimer, node);
527 expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
529 * clock_was_set() has changed base->offset so the
530 * result might be negative. Fix it up to prevent a
531 * false positive in clockevents_program_event()
533 if (expires.tv64 < 0)
535 if (expires.tv64 < expires_next.tv64)
536 expires_next = expires;
539 if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
542 cpu_base->expires_next.tv64 = expires_next.tv64;
544 if (cpu_base->expires_next.tv64 != KTIME_MAX)
545 tick_program_event(cpu_base->expires_next, 1);
549 * Shared reprogramming for clock_realtime and clock_monotonic
551 * When a timer is enqueued and expires earlier than the already enqueued
552 * timers, we have to check, whether it expires earlier than the timer for
553 * which the clock event device was armed.
555 * Called with interrupts disabled and base->cpu_base.lock held
557 static int hrtimer_reprogram(struct hrtimer *timer,
558 struct hrtimer_clock_base *base)
560 ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
561 ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
564 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
567 * When the callback is running, we do not reprogram the clock event
568 * device. The timer callback is either running on a different CPU or
569 * the callback is executed in the hrtimer_interrupt context. The
570 * reprogramming is handled either by the softirq, which called the
571 * callback or at the end of the hrtimer_interrupt.
573 if (hrtimer_callback_running(timer))
577 * CLOCK_REALTIME timer might be requested with an absolute
578 * expiry time which is less than base->offset. Nothing wrong
579 * about that, just avoid to call into the tick code, which
580 * has now objections against negative expiry values.
582 if (expires.tv64 < 0)
585 if (expires.tv64 >= expires_next->tv64)
589 * Clockevents returns -ETIME, when the event was in the past.
591 res = tick_program_event(expires, 0);
592 if (!IS_ERR_VALUE(res))
593 *expires_next = expires;
599 * Retrigger next event is called after clock was set
601 * Called with interrupts disabled via on_each_cpu()
603 static void retrigger_next_event(void *arg)
605 struct hrtimer_cpu_base *base;
606 struct timespec realtime_offset;
609 if (!hrtimer_hres_active())
613 seq = read_seqbegin(&xtime_lock);
614 set_normalized_timespec(&realtime_offset,
615 -wall_to_monotonic.tv_sec,
616 -wall_to_monotonic.tv_nsec);
617 } while (read_seqretry(&xtime_lock, seq));
619 base = &__get_cpu_var(hrtimer_bases);
621 /* Adjust CLOCK_REALTIME offset */
622 spin_lock(&base->lock);
623 base->clock_base[CLOCK_REALTIME].offset =
624 timespec_to_ktime(realtime_offset);
626 hrtimer_force_reprogram(base, 0);
627 spin_unlock(&base->lock);
631 * Clock realtime was set
633 * Change the offset of the realtime clock vs. the monotonic
636 * We might have to reprogram the high resolution timer interrupt. On
637 * SMP we call the architecture specific code to retrigger _all_ high
638 * resolution timer interrupts. On UP we just disable interrupts and
639 * call the high resolution interrupt code.
641 void clock_was_set(void)
643 /* Retrigger the CPU local events everywhere */
644 on_each_cpu(retrigger_next_event, NULL, 1);
648 * During resume we might have to reprogram the high resolution timer
649 * interrupt (on the local CPU):
651 void hres_timers_resume(void)
653 WARN_ONCE(!irqs_disabled(),
654 KERN_INFO "hres_timers_resume() called with IRQs enabled!");
656 retrigger_next_event(NULL);
660 * Initialize the high resolution related parts of cpu_base
662 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
664 base->expires_next.tv64 = KTIME_MAX;
665 base->hres_active = 0;
669 * Initialize the high resolution related parts of a hrtimer
671 static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
677 * When High resolution timers are active, try to reprogram. Note, that in case
678 * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
679 * check happens. The timer gets enqueued into the rbtree. The reprogramming
680 * and expiry check is done in the hrtimer_interrupt or in the softirq.
682 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
683 struct hrtimer_clock_base *base,
686 if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
688 spin_unlock(&base->cpu_base->lock);
689 raise_softirq_irqoff(HRTIMER_SOFTIRQ);
690 spin_lock(&base->cpu_base->lock);
692 __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
701 * Switch to high resolution mode
703 static int hrtimer_switch_to_hres(void)
705 int cpu = smp_processor_id();
706 struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
709 if (base->hres_active)
712 local_irq_save(flags);
714 if (tick_init_highres()) {
715 local_irq_restore(flags);
716 printk(KERN_WARNING "Could not switch to high resolution "
717 "mode on CPU %d\n", cpu);
720 base->hres_active = 1;
721 base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
722 base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
724 tick_setup_sched_timer();
726 /* "Retrigger" the interrupt to get things going */
727 retrigger_next_event(NULL);
728 local_irq_restore(flags);
734 static inline int hrtimer_hres_active(void) { return 0; }
735 static inline int hrtimer_is_hres_enabled(void) { return 0; }
736 static inline int hrtimer_switch_to_hres(void) { return 0; }
738 hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
739 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
740 struct hrtimer_clock_base *base,
745 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
746 static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
748 #endif /* CONFIG_HIGH_RES_TIMERS */
750 #ifdef CONFIG_TIMER_STATS
751 void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr)
753 if (timer->start_site)
756 timer->start_site = addr;
757 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
758 timer->start_pid = current->pid;
763 * Counterpart to lock_hrtimer_base above:
766 void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
768 spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
772 * hrtimer_forward - forward the timer expiry
773 * @timer: hrtimer to forward
774 * @now: forward past this time
775 * @interval: the interval to forward
777 * Forward the timer expiry so it will expire in the future.
778 * Returns the number of overruns.
780 u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
785 delta = ktime_sub(now, hrtimer_get_expires(timer));
790 if (interval.tv64 < timer->base->resolution.tv64)
791 interval.tv64 = timer->base->resolution.tv64;
793 if (unlikely(delta.tv64 >= interval.tv64)) {
794 s64 incr = ktime_to_ns(interval);
796 orun = ktime_divns(delta, incr);
797 hrtimer_add_expires_ns(timer, incr * orun);
798 if (hrtimer_get_expires_tv64(timer) > now.tv64)
801 * This (and the ktime_add() below) is the
802 * correction for exact:
806 hrtimer_add_expires(timer, interval);
810 EXPORT_SYMBOL_GPL(hrtimer_forward);
813 * enqueue_hrtimer - internal function to (re)start a timer
815 * The timer is inserted in expiry order. Insertion into the
816 * red black tree is O(log(n)). Must hold the base lock.
818 * Returns 1 when the new timer is the leftmost timer in the tree.
820 static int enqueue_hrtimer(struct hrtimer *timer,
821 struct hrtimer_clock_base *base)
823 struct rb_node **link = &base->active.rb_node;
824 struct rb_node *parent = NULL;
825 struct hrtimer *entry;
828 debug_activate(timer);
831 * Find the right place in the rbtree:
835 entry = rb_entry(parent, struct hrtimer, node);
837 * We dont care about collisions. Nodes with
838 * the same expiry time stay together.
840 if (hrtimer_get_expires_tv64(timer) <
841 hrtimer_get_expires_tv64(entry)) {
842 link = &(*link)->rb_left;
844 link = &(*link)->rb_right;
850 * Insert the timer to the rbtree and check whether it
851 * replaces the first pending timer
854 base->first = &timer->node;
856 rb_link_node(&timer->node, parent, link);
857 rb_insert_color(&timer->node, &base->active);
859 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
860 * state of a possibly running callback.
862 timer->state |= HRTIMER_STATE_ENQUEUED;
868 * __remove_hrtimer - internal function to remove a timer
870 * Caller must hold the base lock.
872 * High resolution timer mode reprograms the clock event device when the
873 * timer is the one which expires next. The caller can disable this by setting
874 * reprogram to zero. This is useful, when the context does a reprogramming
875 * anyway (e.g. timer interrupt)
877 static void __remove_hrtimer(struct hrtimer *timer,
878 struct hrtimer_clock_base *base,
879 unsigned long newstate, int reprogram)
881 if (!(timer->state & HRTIMER_STATE_ENQUEUED))
885 * Remove the timer from the rbtree and replace the first
886 * entry pointer if necessary.
888 if (base->first == &timer->node) {
889 base->first = rb_next(&timer->node);
890 #ifdef CONFIG_HIGH_RES_TIMERS
891 /* Reprogram the clock event device. if enabled */
892 if (reprogram && hrtimer_hres_active()) {
895 expires = ktime_sub(hrtimer_get_expires(timer),
897 if (base->cpu_base->expires_next.tv64 == expires.tv64)
898 hrtimer_force_reprogram(base->cpu_base, 1);
902 rb_erase(&timer->node, &base->active);
904 timer->state = newstate;
908 * remove hrtimer, called with base lock held
911 remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
913 if (hrtimer_is_queued(timer)) {
917 * Remove the timer and force reprogramming when high
918 * resolution mode is active and the timer is on the current
919 * CPU. If we remove a timer on another CPU, reprogramming is
920 * skipped. The interrupt event on this CPU is fired and
921 * reprogramming happens in the interrupt handler. This is a
922 * rare case and less expensive than a smp call.
924 debug_deactivate(timer);
925 timer_stats_hrtimer_clear_start_info(timer);
926 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
927 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
934 int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
935 unsigned long delta_ns, const enum hrtimer_mode mode,
938 struct hrtimer_clock_base *base, *new_base;
942 base = lock_hrtimer_base(timer, &flags);
944 /* Remove an active timer from the queue: */
945 ret = remove_hrtimer(timer, base);
947 /* Switch the timer base, if necessary: */
948 new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
950 if (mode & HRTIMER_MODE_REL) {
951 tim = ktime_add_safe(tim, new_base->get_time());
953 * CONFIG_TIME_LOW_RES is a temporary way for architectures
954 * to signal that they simply return xtime in
955 * do_gettimeoffset(). In this case we want to round up by
956 * resolution when starting a relative timer, to avoid short
957 * timeouts. This will go away with the GTOD framework.
959 #ifdef CONFIG_TIME_LOW_RES
960 tim = ktime_add_safe(tim, base->resolution);
964 hrtimer_set_expires_range_ns(timer, tim, delta_ns);
966 timer_stats_hrtimer_set_start_info(timer);
968 leftmost = enqueue_hrtimer(timer, new_base);
971 * Only allow reprogramming if the new base is on this CPU.
972 * (it might still be on another CPU if the timer was pending)
974 * XXX send_remote_softirq() ?
976 if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
977 hrtimer_enqueue_reprogram(timer, new_base, wakeup);
979 unlock_hrtimer_base(timer, &flags);
985 * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
986 * @timer: the timer to be added
988 * @delta_ns: "slack" range for the timer
989 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
993 * 1 when the timer was active
995 int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
996 unsigned long delta_ns, const enum hrtimer_mode mode)
998 return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1);
1000 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
1003 * hrtimer_start - (re)start an hrtimer on the current CPU
1004 * @timer: the timer to be added
1006 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
1010 * 1 when the timer was active
1013 hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
1015 return __hrtimer_start_range_ns(timer, tim, 0, mode, 1);
1017 EXPORT_SYMBOL_GPL(hrtimer_start);
1021 * hrtimer_try_to_cancel - try to deactivate a timer
1022 * @timer: hrtimer to stop
1025 * 0 when the timer was not active
1026 * 1 when the timer was active
1027 * -1 when the timer is currently excuting the callback function and
1030 int hrtimer_try_to_cancel(struct hrtimer *timer)
1032 struct hrtimer_clock_base *base;
1033 unsigned long flags;
1036 base = lock_hrtimer_base(timer, &flags);
1038 if (!hrtimer_callback_running(timer))
1039 ret = remove_hrtimer(timer, base);
1041 unlock_hrtimer_base(timer, &flags);
1046 EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
1049 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
1050 * @timer: the timer to be cancelled
1053 * 0 when the timer was not active
1054 * 1 when the timer was active
1056 int hrtimer_cancel(struct hrtimer *timer)
1059 int ret = hrtimer_try_to_cancel(timer);
1066 EXPORT_SYMBOL_GPL(hrtimer_cancel);
1069 * hrtimer_get_remaining - get remaining time for the timer
1070 * @timer: the timer to read
1072 ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
1074 struct hrtimer_clock_base *base;
1075 unsigned long flags;
1078 base = lock_hrtimer_base(timer, &flags);
1079 rem = hrtimer_expires_remaining(timer);
1080 unlock_hrtimer_base(timer, &flags);
1084 EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
1088 * hrtimer_get_next_event - get the time until next expiry event
1090 * Returns the delta to the next expiry event or KTIME_MAX if no timer
1093 ktime_t hrtimer_get_next_event(void)
1095 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1096 struct hrtimer_clock_base *base = cpu_base->clock_base;
1097 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
1098 unsigned long flags;
1101 spin_lock_irqsave(&cpu_base->lock, flags);
1103 if (!hrtimer_hres_active()) {
1104 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
1105 struct hrtimer *timer;
1110 timer = rb_entry(base->first, 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 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);
1141 #ifdef CONFIG_TIMER_STATS
1142 timer->start_site = NULL;
1143 timer->start_pid = -1;
1144 memset(timer->start_comm, 0, TASK_COMM_LEN);
1149 * hrtimer_init - initialize a timer to the given clock
1150 * @timer: the timer to be initialized
1151 * @clock_id: the clock to be used
1152 * @mode: timer mode abs/rel
1154 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1155 enum hrtimer_mode mode)
1157 debug_init(timer, clock_id, mode);
1158 __hrtimer_init(timer, clock_id, mode);
1160 EXPORT_SYMBOL_GPL(hrtimer_init);
1163 * hrtimer_get_res - get the timer resolution for a clock
1164 * @which_clock: which clock to query
1165 * @tp: pointer to timespec variable to store the resolution
1167 * Store the resolution of the clock selected by @which_clock in the
1168 * variable pointed to by @tp.
1170 int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1172 struct hrtimer_cpu_base *cpu_base;
1174 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1175 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
1179 EXPORT_SYMBOL_GPL(hrtimer_get_res);
1181 static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
1183 struct hrtimer_clock_base *base = timer->base;
1184 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1185 enum hrtimer_restart (*fn)(struct hrtimer *);
1188 WARN_ON(!irqs_disabled());
1190 debug_deactivate(timer);
1191 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1192 timer_stats_account_hrtimer(timer);
1193 fn = timer->function;
1196 * Because we run timers from hardirq context, there is no chance
1197 * they get migrated to another cpu, therefore its safe to unlock
1200 spin_unlock(&cpu_base->lock);
1201 trace_hrtimer_expire_entry(timer, now);
1202 restart = fn(timer);
1203 trace_hrtimer_expire_exit(timer);
1204 spin_lock(&cpu_base->lock);
1207 * Note: We clear the CALLBACK bit after enqueue_hrtimer and
1208 * we do not reprogramm the event hardware. Happens either in
1209 * hrtimer_start_range_ns() or in hrtimer_interrupt()
1211 if (restart != HRTIMER_NORESTART) {
1212 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1213 enqueue_hrtimer(timer, base);
1215 timer->state &= ~HRTIMER_STATE_CALLBACK;
1218 #ifdef CONFIG_HIGH_RES_TIMERS
1220 static int force_clock_reprogram;
1223 * After 5 iteration's attempts, we consider that hrtimer_interrupt()
1224 * is hanging, which could happen with something that slows the interrupt
1225 * such as the tracing. Then we force the clock reprogramming for each future
1226 * hrtimer interrupts to avoid infinite loops and use the min_delta_ns
1227 * threshold that we will overwrite.
1228 * The next tick event will be scheduled to 3 times we currently spend on
1229 * hrtimer_interrupt(). This gives a good compromise, the cpus will spend
1230 * 1/4 of their time to process the hrtimer interrupts. This is enough to
1231 * let it running without serious starvation.
1235 hrtimer_interrupt_hanging(struct clock_event_device *dev,
1238 force_clock_reprogram = 1;
1239 dev->min_delta_ns = (unsigned long)try_time.tv64 * 3;
1240 printk(KERN_WARNING "hrtimer: interrupt too slow, "
1241 "forcing clock min delta to %lu ns\n", dev->min_delta_ns);
1244 * High resolution timer interrupt
1245 * Called with interrupts disabled
1247 void hrtimer_interrupt(struct clock_event_device *dev)
1249 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1250 struct hrtimer_clock_base *base;
1251 ktime_t expires_next, now;
1255 BUG_ON(!cpu_base->hres_active);
1256 cpu_base->nr_events++;
1257 dev->next_event.tv64 = KTIME_MAX;
1260 /* 5 retries is enough to notice a hang */
1261 if (!(++nr_retries % 5))
1262 hrtimer_interrupt_hanging(dev, ktime_sub(ktime_get(), now));
1266 expires_next.tv64 = KTIME_MAX;
1268 spin_lock(&cpu_base->lock);
1270 * We set expires_next to KTIME_MAX here with cpu_base->lock
1271 * held to prevent that a timer is enqueued in our queue via
1272 * the migration code. This does not affect enqueueing of
1273 * timers which run their callback and need to be requeued on
1276 cpu_base->expires_next.tv64 = KTIME_MAX;
1278 base = cpu_base->clock_base;
1280 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1282 struct rb_node *node;
1284 basenow = ktime_add(now, base->offset);
1286 while ((node = base->first)) {
1287 struct hrtimer *timer;
1289 timer = rb_entry(node, struct hrtimer, node);
1292 * The immediate goal for using the softexpires is
1293 * minimizing wakeups, not running timers at the
1294 * earliest interrupt after their soft expiration.
1295 * This allows us to avoid using a Priority Search
1296 * Tree, which can answer a stabbing querry for
1297 * overlapping intervals and instead use the simple
1298 * BST we already have.
1299 * We don't add extra wakeups by delaying timers that
1300 * are right-of a not yet expired timer, because that
1301 * timer will have to trigger a wakeup anyway.
1304 if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
1307 expires = ktime_sub(hrtimer_get_expires(timer),
1309 if (expires.tv64 < expires_next.tv64)
1310 expires_next = expires;
1314 __run_hrtimer(timer, &basenow);
1320 * Store the new expiry value so the migration code can verify
1323 cpu_base->expires_next = expires_next;
1324 spin_unlock(&cpu_base->lock);
1326 /* Reprogramming necessary ? */
1327 if (expires_next.tv64 != KTIME_MAX) {
1328 if (tick_program_event(expires_next, force_clock_reprogram))
1334 * local version of hrtimer_peek_ahead_timers() called with interrupts
1337 static void __hrtimer_peek_ahead_timers(void)
1339 struct tick_device *td;
1341 if (!hrtimer_hres_active())
1344 td = &__get_cpu_var(tick_cpu_device);
1345 if (td && td->evtdev)
1346 hrtimer_interrupt(td->evtdev);
1350 * hrtimer_peek_ahead_timers -- run soft-expired timers now
1352 * hrtimer_peek_ahead_timers will peek at the timer queue of
1353 * the current cpu and check if there are any timers for which
1354 * the soft expires time has passed. If any such timers exist,
1355 * they are run immediately and then removed from the timer queue.
1358 void hrtimer_peek_ahead_timers(void)
1360 unsigned long flags;
1362 local_irq_save(flags);
1363 __hrtimer_peek_ahead_timers();
1364 local_irq_restore(flags);
1367 static void run_hrtimer_softirq(struct softirq_action *h)
1369 hrtimer_peek_ahead_timers();
1372 #else /* CONFIG_HIGH_RES_TIMERS */
1374 static inline void __hrtimer_peek_ahead_timers(void) { }
1376 #endif /* !CONFIG_HIGH_RES_TIMERS */
1379 * Called from timer softirq every jiffy, expire hrtimers:
1381 * For HRT its the fall back code to run the softirq in the timer
1382 * softirq context in case the hrtimer initialization failed or has
1383 * not been done yet.
1385 void hrtimer_run_pending(void)
1387 if (hrtimer_hres_active())
1391 * This _is_ ugly: We have to check in the softirq context,
1392 * whether we can switch to highres and / or nohz mode. The
1393 * clocksource switch happens in the timer interrupt with
1394 * xtime_lock held. Notification from there only sets the
1395 * check bit in the tick_oneshot code, otherwise we might
1396 * deadlock vs. xtime_lock.
1398 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1399 hrtimer_switch_to_hres();
1403 * Called from hardirq context every jiffy
1405 void hrtimer_run_queues(void)
1407 struct rb_node *node;
1408 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1409 struct hrtimer_clock_base *base;
1410 int index, gettime = 1;
1412 if (hrtimer_hres_active())
1415 for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
1416 base = &cpu_base->clock_base[index];
1422 hrtimer_get_softirq_time(cpu_base);
1426 spin_lock(&cpu_base->lock);
1428 while ((node = base->first)) {
1429 struct hrtimer *timer;
1431 timer = rb_entry(node, struct hrtimer, node);
1432 if (base->softirq_time.tv64 <=
1433 hrtimer_get_expires_tv64(timer))
1436 __run_hrtimer(timer, &base->softirq_time);
1438 spin_unlock(&cpu_base->lock);
1443 * Sleep related functions:
1445 static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
1447 struct hrtimer_sleeper *t =
1448 container_of(timer, struct hrtimer_sleeper, timer);
1449 struct task_struct *task = t->task;
1453 wake_up_process(task);
1455 return HRTIMER_NORESTART;
1458 void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
1460 sl->timer.function = hrtimer_wakeup;
1463 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
1465 static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
1467 hrtimer_init_sleeper(t, current);
1470 set_current_state(TASK_INTERRUPTIBLE);
1471 hrtimer_start_expires(&t->timer, mode);
1472 if (!hrtimer_active(&t->timer))
1475 if (likely(t->task))
1478 hrtimer_cancel(&t->timer);
1479 mode = HRTIMER_MODE_ABS;
1481 } while (t->task && !signal_pending(current));
1483 __set_current_state(TASK_RUNNING);
1485 return t->task == NULL;
1488 static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
1490 struct timespec rmt;
1493 rem = hrtimer_expires_remaining(timer);
1496 rmt = ktime_to_timespec(rem);
1498 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1504 long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1506 struct hrtimer_sleeper t;
1507 struct timespec __user *rmtp;
1510 hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
1512 hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
1514 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1517 rmtp = restart->nanosleep.rmtp;
1519 ret = update_rmtp(&t.timer, rmtp);
1524 /* The other values in restart are already filled in */
1525 ret = -ERESTART_RESTARTBLOCK;
1527 destroy_hrtimer_on_stack(&t.timer);
1531 long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1532 const enum hrtimer_mode mode, const clockid_t clockid)
1534 struct restart_block *restart;
1535 struct hrtimer_sleeper t;
1537 unsigned long slack;
1539 slack = current->timer_slack_ns;
1540 if (rt_task(current))
1543 hrtimer_init_on_stack(&t.timer, clockid, mode);
1544 hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1545 if (do_nanosleep(&t, mode))
1548 /* Absolute timers do not update the rmtp value and restart: */
1549 if (mode == HRTIMER_MODE_ABS) {
1550 ret = -ERESTARTNOHAND;
1555 ret = update_rmtp(&t.timer, rmtp);
1560 restart = ¤t_thread_info()->restart_block;
1561 restart->fn = hrtimer_nanosleep_restart;
1562 restart->nanosleep.index = t.timer.base->index;
1563 restart->nanosleep.rmtp = rmtp;
1564 restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
1566 ret = -ERESTART_RESTARTBLOCK;
1568 destroy_hrtimer_on_stack(&t.timer);
1572 SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
1573 struct timespec __user *, rmtp)
1577 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1580 if (!timespec_valid(&tu))
1583 return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
1587 * Functions related to boot-time initialization:
1589 static void __cpuinit init_hrtimers_cpu(int cpu)
1591 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
1594 spin_lock_init(&cpu_base->lock);
1596 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1597 cpu_base->clock_base[i].cpu_base = cpu_base;
1599 hrtimer_init_hres(cpu_base);
1602 #ifdef CONFIG_HOTPLUG_CPU
1604 static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1605 struct hrtimer_clock_base *new_base)
1607 struct hrtimer *timer;
1608 struct rb_node *node;
1610 while ((node = rb_first(&old_base->active))) {
1611 timer = rb_entry(node, struct hrtimer, node);
1612 BUG_ON(hrtimer_callback_running(timer));
1613 debug_deactivate(timer);
1616 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
1617 * timer could be seen as !active and just vanish away
1618 * under us on another CPU
1620 __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
1621 timer->base = new_base;
1623 * Enqueue the timers on the new cpu. This does not
1624 * reprogram the event device in case the timer
1625 * expires before the earliest on this CPU, but we run
1626 * hrtimer_interrupt after we migrated everything to
1627 * sort out already expired timers and reprogram the
1630 enqueue_hrtimer(timer, new_base);
1632 /* Clear the migration state bit */
1633 timer->state &= ~HRTIMER_STATE_MIGRATE;
1637 static void migrate_hrtimers(int scpu)
1639 struct hrtimer_cpu_base *old_base, *new_base;
1642 BUG_ON(cpu_online(scpu));
1643 tick_cancel_sched_timer(scpu);
1645 local_irq_disable();
1646 old_base = &per_cpu(hrtimer_bases, scpu);
1647 new_base = &__get_cpu_var(hrtimer_bases);
1649 * The caller is globally serialized and nobody else
1650 * takes two locks at once, deadlock is not possible.
1652 spin_lock(&new_base->lock);
1653 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1655 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1656 migrate_hrtimer_list(&old_base->clock_base[i],
1657 &new_base->clock_base[i]);
1660 spin_unlock(&old_base->lock);
1661 spin_unlock(&new_base->lock);
1663 /* Check, if we got expired work to do */
1664 __hrtimer_peek_ahead_timers();
1668 #endif /* CONFIG_HOTPLUG_CPU */
1670 static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
1671 unsigned long action, void *hcpu)
1673 int scpu = (long)hcpu;
1677 case CPU_UP_PREPARE:
1678 case CPU_UP_PREPARE_FROZEN:
1679 init_hrtimers_cpu(scpu);
1682 #ifdef CONFIG_HOTPLUG_CPU
1684 case CPU_DYING_FROZEN:
1685 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu);
1688 case CPU_DEAD_FROZEN:
1690 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu);
1691 migrate_hrtimers(scpu);
1703 static struct notifier_block __cpuinitdata hrtimers_nb = {
1704 .notifier_call = hrtimer_cpu_notify,
1707 void __init hrtimers_init(void)
1709 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1710 (void *)(long)smp_processor_id());
1711 register_cpu_notifier(&hrtimers_nb);
1712 #ifdef CONFIG_HIGH_RES_TIMERS
1713 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
1718 * schedule_hrtimeout_range - sleep until timeout
1719 * @expires: timeout value (ktime_t)
1720 * @delta: slack in expires timeout (ktime_t)
1721 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1723 * Make the current task sleep until the given expiry time has
1724 * elapsed. The routine will return immediately unless
1725 * the current task state has been set (see set_current_state()).
1727 * The @delta argument gives the kernel the freedom to schedule the
1728 * actual wakeup to a time that is both power and performance friendly.
1729 * The kernel give the normal best effort behavior for "@expires+@delta",
1730 * but may decide to fire the timer earlier, but no earlier than @expires.
1732 * You can set the task state as follows -
1734 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1735 * pass before the routine returns.
1737 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1738 * delivered to the current task.
1740 * The current task state is guaranteed to be TASK_RUNNING when this
1743 * Returns 0 when the timer has expired otherwise -EINTR
1745 int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
1746 const enum hrtimer_mode mode)
1748 struct hrtimer_sleeper t;
1751 * Optimize when a zero timeout value is given. It does not
1752 * matter whether this is an absolute or a relative time.
1754 if (expires && !expires->tv64) {
1755 __set_current_state(TASK_RUNNING);
1760 * A NULL parameter means "inifinte"
1764 __set_current_state(TASK_RUNNING);
1768 hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);
1769 hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
1771 hrtimer_init_sleeper(&t, current);
1773 hrtimer_start_expires(&t.timer, mode);
1774 if (!hrtimer_active(&t.timer))
1780 hrtimer_cancel(&t.timer);
1781 destroy_hrtimer_on_stack(&t.timer);
1783 __set_current_state(TASK_RUNNING);
1785 return !t.task ? 0 : -EINTR;
1787 EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
1790 * schedule_hrtimeout - sleep until timeout
1791 * @expires: timeout value (ktime_t)
1792 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1794 * Make the current task sleep until the given expiry time has
1795 * elapsed. The routine will return immediately unless
1796 * the current task state has been set (see set_current_state()).
1798 * You can set the task state as follows -
1800 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1801 * pass before the routine returns.
1803 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1804 * delivered to the current task.
1806 * The current task state is guaranteed to be TASK_RUNNING when this
1809 * Returns 0 when the timer has expired otherwise -EINTR
1811 int __sched schedule_hrtimeout(ktime_t *expires,
1812 const enum hrtimer_mode mode)
1814 return schedule_hrtimeout_range(expires, 0, mode);
1816 EXPORT_SYMBOL_GPL(schedule_hrtimeout);