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/export.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/sched/sysctl.h>
48 #include <linux/sched/rt.h>
49 #include <linux/sched/deadline.h>
50 #include <linux/timer.h>
51 #include <linux/freezer.h>
53 #include <asm/uaccess.h>
55 #include <trace/events/timer.h>
57 #include "tick-internal.h"
62 * There are more clockids then hrtimer bases. Thus, we index
63 * into the timer bases by the hrtimer_base_type enum. When trying
64 * to reach a base using a clockid, hrtimer_clockid_to_base()
65 * is used to convert from clockid to the proper hrtimer_base_type.
67 DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
69 .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock),
73 .index = HRTIMER_BASE_MONOTONIC,
74 .clockid = CLOCK_MONOTONIC,
75 .get_time = &ktime_get,
78 .index = HRTIMER_BASE_REALTIME,
79 .clockid = CLOCK_REALTIME,
80 .get_time = &ktime_get_real,
83 .index = HRTIMER_BASE_BOOTTIME,
84 .clockid = CLOCK_BOOTTIME,
85 .get_time = &ktime_get_boottime,
88 .index = HRTIMER_BASE_TAI,
90 .get_time = &ktime_get_clocktai,
95 static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
96 [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
97 [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
98 [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,
99 [CLOCK_TAI] = HRTIMER_BASE_TAI,
102 static inline int hrtimer_clockid_to_base(clockid_t clock_id)
104 return hrtimer_clock_to_base_table[clock_id];
108 * Functions and macros which are different for UP/SMP systems are kept in a
114 * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
115 * means that all timers which are tied to this base via timer->base are
116 * locked, and the base itself is locked too.
118 * So __run_timers/migrate_timers can safely modify all timers which could
119 * be found on the lists/queues.
121 * When the timer's base is locked, and the timer removed from list, it is
122 * possible to set timer->base = NULL and drop the lock: the timer remains
126 struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
127 unsigned long *flags)
129 struct hrtimer_clock_base *base;
133 if (likely(base != NULL)) {
134 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
135 if (likely(base == timer->base))
137 /* The timer has migrated to another CPU: */
138 raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
145 * With HIGHRES=y we do not migrate the timer when it is expiring
146 * before the next event on the target cpu because we cannot reprogram
147 * the target cpu hardware and we would cause it to fire late.
149 * Called with cpu_base->lock of target cpu held.
152 hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base)
154 #ifdef CONFIG_HIGH_RES_TIMERS
157 if (!new_base->cpu_base->hres_active)
160 expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
161 return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
168 * Switch the timer base to the current CPU when possible.
170 static inline struct hrtimer_clock_base *
171 switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
174 struct hrtimer_clock_base *new_base;
175 struct hrtimer_cpu_base *new_cpu_base;
176 int this_cpu = smp_processor_id();
177 int cpu = get_nohz_timer_target(pinned);
178 int basenum = base->index;
181 new_cpu_base = &per_cpu(hrtimer_bases, cpu);
182 new_base = &new_cpu_base->clock_base[basenum];
184 if (base != new_base) {
186 * We are trying to move timer to new_base.
187 * However we can't change timer's base while it is running,
188 * so we keep it on the same CPU. No hassle vs. reprogramming
189 * the event source in the high resolution case. The softirq
190 * code will take care of this when the timer function has
191 * completed. There is no conflict as we hold the lock until
192 * the timer is enqueued.
194 if (unlikely(hrtimer_callback_running(timer)))
197 /* See the comment in lock_timer_base() */
199 raw_spin_unlock(&base->cpu_base->lock);
200 raw_spin_lock(&new_base->cpu_base->lock);
202 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
204 raw_spin_unlock(&new_base->cpu_base->lock);
205 raw_spin_lock(&base->cpu_base->lock);
209 timer->base = new_base;
211 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
219 #else /* CONFIG_SMP */
221 static inline struct hrtimer_clock_base *
222 lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
224 struct hrtimer_clock_base *base = timer->base;
226 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
231 # define switch_hrtimer_base(t, b, p) (b)
233 #endif /* !CONFIG_SMP */
236 * Functions for the union type storage format of ktime_t which are
237 * too large for inlining:
239 #if BITS_PER_LONG < 64
241 * Divide a ktime value by a nanosecond value
243 u64 __ktime_divns(const ktime_t kt, s64 div)
248 dclc = ktime_to_ns(kt);
249 /* Make sure the divisor is less than 2^32: */
255 do_div(dclc, (unsigned long) div);
259 EXPORT_SYMBOL_GPL(__ktime_divns);
260 #endif /* BITS_PER_LONG >= 64 */
263 * Add two ktime values and do a safety check for overflow:
265 ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
267 ktime_t res = ktime_add(lhs, rhs);
270 * We use KTIME_SEC_MAX here, the maximum timeout which we can
271 * return to user space in a timespec:
273 if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
274 res = ktime_set(KTIME_SEC_MAX, 0);
279 EXPORT_SYMBOL_GPL(ktime_add_safe);
281 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
283 static struct debug_obj_descr hrtimer_debug_descr;
285 static void *hrtimer_debug_hint(void *addr)
287 return ((struct hrtimer *) addr)->function;
291 * fixup_init is called when:
292 * - an active object is initialized
294 static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
296 struct hrtimer *timer = addr;
299 case ODEBUG_STATE_ACTIVE:
300 hrtimer_cancel(timer);
301 debug_object_init(timer, &hrtimer_debug_descr);
309 * fixup_activate is called when:
310 * - an active object is activated
311 * - an unknown object is activated (might be a statically initialized object)
313 static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
317 case ODEBUG_STATE_NOTAVAILABLE:
321 case ODEBUG_STATE_ACTIVE:
330 * fixup_free is called when:
331 * - an active object is freed
333 static int hrtimer_fixup_free(void *addr, enum debug_obj_state state)
335 struct hrtimer *timer = addr;
338 case ODEBUG_STATE_ACTIVE:
339 hrtimer_cancel(timer);
340 debug_object_free(timer, &hrtimer_debug_descr);
347 static struct debug_obj_descr hrtimer_debug_descr = {
349 .debug_hint = hrtimer_debug_hint,
350 .fixup_init = hrtimer_fixup_init,
351 .fixup_activate = hrtimer_fixup_activate,
352 .fixup_free = hrtimer_fixup_free,
355 static inline void debug_hrtimer_init(struct hrtimer *timer)
357 debug_object_init(timer, &hrtimer_debug_descr);
360 static inline void debug_hrtimer_activate(struct hrtimer *timer)
362 debug_object_activate(timer, &hrtimer_debug_descr);
365 static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
367 debug_object_deactivate(timer, &hrtimer_debug_descr);
370 static inline void debug_hrtimer_free(struct hrtimer *timer)
372 debug_object_free(timer, &hrtimer_debug_descr);
375 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
376 enum hrtimer_mode mode);
378 void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
379 enum hrtimer_mode mode)
381 debug_object_init_on_stack(timer, &hrtimer_debug_descr);
382 __hrtimer_init(timer, clock_id, mode);
384 EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
386 void destroy_hrtimer_on_stack(struct hrtimer *timer)
388 debug_object_free(timer, &hrtimer_debug_descr);
392 static inline void debug_hrtimer_init(struct hrtimer *timer) { }
393 static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
394 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
398 debug_init(struct hrtimer *timer, clockid_t clockid,
399 enum hrtimer_mode mode)
401 debug_hrtimer_init(timer);
402 trace_hrtimer_init(timer, clockid, mode);
405 static inline void debug_activate(struct hrtimer *timer)
407 debug_hrtimer_activate(timer);
408 trace_hrtimer_start(timer);
411 static inline void debug_deactivate(struct hrtimer *timer)
413 debug_hrtimer_deactivate(timer);
414 trace_hrtimer_cancel(timer);
417 #if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
418 static inline void hrtimer_update_next_timer(struct hrtimer_cpu_base *cpu_base,
419 struct hrtimer *timer)
421 #ifdef CONFIG_HIGH_RES_TIMERS
422 cpu_base->next_timer = timer;
426 static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base)
428 struct hrtimer_clock_base *base = cpu_base->clock_base;
429 ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
430 unsigned int active = cpu_base->active_bases;
432 hrtimer_update_next_timer(cpu_base, NULL);
433 for (; active; base++, active >>= 1) {
434 struct timerqueue_node *next;
435 struct hrtimer *timer;
437 if (!(active & 0x01))
440 next = timerqueue_getnext(&base->active);
441 timer = container_of(next, struct hrtimer, node);
442 expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
443 if (expires.tv64 < expires_next.tv64) {
444 expires_next = expires;
445 hrtimer_update_next_timer(cpu_base, timer);
449 * clock_was_set() might have changed base->offset of any of
450 * the clock bases so the result might be negative. Fix it up
451 * to prevent a false positive in clockevents_program_event().
453 if (expires_next.tv64 < 0)
454 expires_next.tv64 = 0;
459 static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
461 ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
462 ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
463 ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset;
465 return ktime_get_update_offsets_now(&base->clock_was_set_seq,
466 offs_real, offs_boot, offs_tai);
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;
476 unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC;
477 EXPORT_SYMBOL_GPL(hrtimer_resolution);
480 * Enable / Disable high resolution mode
482 static int __init setup_hrtimer_hres(char *str)
484 if (!strcmp(str, "off"))
485 hrtimer_hres_enabled = 0;
486 else if (!strcmp(str, "on"))
487 hrtimer_hres_enabled = 1;
493 __setup("highres=", setup_hrtimer_hres);
496 * hrtimer_high_res_enabled - query, if the highres mode is enabled
498 static inline int hrtimer_is_hres_enabled(void)
500 return hrtimer_hres_enabled;
504 * Is the high resolution mode active ?
506 static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base)
508 return cpu_base->hres_active;
511 static inline int hrtimer_hres_active(void)
513 return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases));
517 * Reprogram the event source with checking both queues for the
519 * Called with interrupts disabled and base->lock held
522 hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
524 ktime_t expires_next;
526 if (!cpu_base->hres_active)
529 expires_next = __hrtimer_get_next_event(cpu_base);
531 if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
534 cpu_base->expires_next.tv64 = expires_next.tv64;
537 * If a hang was detected in the last timer interrupt then we
538 * leave the hang delay active in the hardware. We want the
539 * system to make progress. That also prevents the following
541 * T1 expires 50ms from now
542 * T2 expires 5s from now
544 * T1 is removed, so this code is called and would reprogram
545 * the hardware to 5s from now. Any hrtimer_start after that
546 * will not reprogram the hardware due to hang_detected being
547 * set. So we'd effectivly block all timers until the T2 event
550 if (cpu_base->hang_detected)
553 tick_program_event(cpu_base->expires_next, 1);
557 * When a timer is enqueued and expires earlier than the already enqueued
558 * timers, we have to check, whether it expires earlier than the timer for
559 * which the clock event device was armed.
561 * Called with interrupts disabled and base->cpu_base.lock held
563 static void hrtimer_reprogram(struct hrtimer *timer,
564 struct hrtimer_clock_base *base)
566 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
567 ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
569 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
572 * If the timer is not on the current cpu, we cannot reprogram
573 * the other cpus clock event device.
575 if (base->cpu_base != cpu_base)
579 * If the hrtimer interrupt is running, then it will
580 * reevaluate the clock bases and reprogram the clock event
581 * device. The callbacks are always executed in hard interrupt
582 * context so we don't need an extra check for a running
585 if (cpu_base->in_hrtirq)
589 * CLOCK_REALTIME timer might be requested with an absolute
590 * expiry time which is less than base->offset. Set it to 0.
592 if (expires.tv64 < 0)
595 if (expires.tv64 >= cpu_base->expires_next.tv64)
598 /* Update the pointer to the next expiring timer */
599 cpu_base->next_timer = timer;
602 * If a hang was detected in the last timer interrupt then we
603 * do not schedule a timer which is earlier than the expiry
604 * which we enforced in the hang detection. We want the system
607 if (cpu_base->hang_detected)
611 * Program the timer hardware. We enforce the expiry for
612 * events which are already in the past.
614 cpu_base->expires_next = expires;
615 tick_program_event(expires, 1);
619 * Initialize the high resolution related parts of cpu_base
621 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
623 base->expires_next.tv64 = KTIME_MAX;
624 base->hres_active = 0;
628 * Retrigger next event is called after clock was set
630 * Called with interrupts disabled via on_each_cpu()
632 static void retrigger_next_event(void *arg)
634 struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
636 if (!base->hres_active)
639 raw_spin_lock(&base->lock);
640 hrtimer_update_base(base);
641 hrtimer_force_reprogram(base, 0);
642 raw_spin_unlock(&base->lock);
646 * Switch to high resolution mode
648 static int hrtimer_switch_to_hres(void)
650 struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
652 if (tick_init_highres()) {
653 printk(KERN_WARNING "Could not switch to high resolution "
654 "mode on CPU %d\n", base->cpu);
657 base->hres_active = 1;
658 hrtimer_resolution = HIGH_RES_NSEC;
660 tick_setup_sched_timer();
661 /* "Retrigger" the interrupt to get things going */
662 retrigger_next_event(NULL);
666 static void clock_was_set_work(struct work_struct *work)
671 static DECLARE_WORK(hrtimer_work, clock_was_set_work);
674 * Called from timekeeping and resume code to reprogramm the hrtimer
675 * interrupt device on all cpus.
677 void clock_was_set_delayed(void)
679 schedule_work(&hrtimer_work);
684 static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *b) { return 0; }
685 static inline int hrtimer_hres_active(void) { return 0; }
686 static inline int hrtimer_is_hres_enabled(void) { return 0; }
687 static inline int hrtimer_switch_to_hres(void) { return 0; }
689 hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
690 static inline int hrtimer_reprogram(struct hrtimer *timer,
691 struct hrtimer_clock_base *base)
695 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
696 static inline void retrigger_next_event(void *arg) { }
698 #endif /* CONFIG_HIGH_RES_TIMERS */
701 * Clock realtime was set
703 * Change the offset of the realtime clock vs. the monotonic
706 * We might have to reprogram the high resolution timer interrupt. On
707 * SMP we call the architecture specific code to retrigger _all_ high
708 * resolution timer interrupts. On UP we just disable interrupts and
709 * call the high resolution interrupt code.
711 void clock_was_set(void)
713 #ifdef CONFIG_HIGH_RES_TIMERS
714 /* Retrigger the CPU local events everywhere */
715 on_each_cpu(retrigger_next_event, NULL, 1);
717 timerfd_clock_was_set();
721 * During resume we might have to reprogram the high resolution timer
722 * interrupt on all online CPUs. However, all other CPUs will be
723 * stopped with IRQs interrupts disabled so the clock_was_set() call
726 void hrtimers_resume(void)
728 WARN_ONCE(!irqs_disabled(),
729 KERN_INFO "hrtimers_resume() called with IRQs enabled!");
731 /* Retrigger on the local CPU */
732 retrigger_next_event(NULL);
733 /* And schedule a retrigger for all others */
734 clock_was_set_delayed();
737 static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
739 #ifdef CONFIG_TIMER_STATS
740 if (timer->start_site)
742 timer->start_site = __builtin_return_address(0);
743 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
744 timer->start_pid = current->pid;
748 static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
750 #ifdef CONFIG_TIMER_STATS
751 timer->start_site = NULL;
755 static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
757 #ifdef CONFIG_TIMER_STATS
758 if (likely(!timer_stats_active))
760 timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
761 timer->function, timer->start_comm, 0);
766 * Counterpart to lock_hrtimer_base above:
769 void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
771 raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
775 * hrtimer_forward - forward the timer expiry
776 * @timer: hrtimer to forward
777 * @now: forward past this time
778 * @interval: the interval to forward
780 * Forward the timer expiry so it will expire in the future.
781 * Returns the number of overruns.
783 * Can be safely called from the callback function of @timer. If
784 * called from other contexts @timer must neither be enqueued nor
785 * running the callback and the caller needs to take care of
788 * Note: This only updates the timer expiry value and does not requeue
791 u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
796 delta = ktime_sub(now, hrtimer_get_expires(timer));
801 if (WARN_ON(timer->state & HRTIMER_STATE_ENQUEUED))
804 if (interval.tv64 < hrtimer_resolution)
805 interval.tv64 = hrtimer_resolution;
807 if (unlikely(delta.tv64 >= interval.tv64)) {
808 s64 incr = ktime_to_ns(interval);
810 orun = ktime_divns(delta, incr);
811 hrtimer_add_expires_ns(timer, incr * orun);
812 if (hrtimer_get_expires_tv64(timer) > now.tv64)
815 * This (and the ktime_add() below) is the
816 * correction for exact:
820 hrtimer_add_expires(timer, interval);
824 EXPORT_SYMBOL_GPL(hrtimer_forward);
827 * enqueue_hrtimer - internal function to (re)start a timer
829 * The timer is inserted in expiry order. Insertion into the
830 * red black tree is O(log(n)). Must hold the base lock.
832 * Returns 1 when the new timer is the leftmost timer in the tree.
834 static int enqueue_hrtimer(struct hrtimer *timer,
835 struct hrtimer_clock_base *base)
837 debug_activate(timer);
839 base->cpu_base->active_bases |= 1 << base->index;
842 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
843 * state of a possibly running callback.
845 timer->state |= HRTIMER_STATE_ENQUEUED;
847 return timerqueue_add(&base->active, &timer->node);
851 * __remove_hrtimer - internal function to remove a timer
853 * Caller must hold the base lock.
855 * High resolution timer mode reprograms the clock event device when the
856 * timer is the one which expires next. The caller can disable this by setting
857 * reprogram to zero. This is useful, when the context does a reprogramming
858 * anyway (e.g. timer interrupt)
860 static void __remove_hrtimer(struct hrtimer *timer,
861 struct hrtimer_clock_base *base,
862 unsigned long newstate, int reprogram)
864 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
865 unsigned int state = timer->state;
867 timer->state = newstate;
868 if (!(state & HRTIMER_STATE_ENQUEUED))
871 if (!timerqueue_del(&base->active, &timer->node))
872 cpu_base->active_bases &= ~(1 << base->index);
874 #ifdef CONFIG_HIGH_RES_TIMERS
876 * Note: If reprogram is false we do not update
877 * cpu_base->next_timer. This happens when we remove the first
878 * timer on a remote cpu. No harm as we never dereference
879 * cpu_base->next_timer. So the worst thing what can happen is
880 * an superflous call to hrtimer_force_reprogram() on the
881 * remote cpu later on if the same timer gets enqueued again.
883 if (reprogram && timer == cpu_base->next_timer)
884 hrtimer_force_reprogram(cpu_base, 1);
889 * remove hrtimer, called with base lock held
892 remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
894 if (hrtimer_is_queued(timer)) {
899 * Remove the timer and force reprogramming when high
900 * resolution mode is active and the timer is on the current
901 * CPU. If we remove a timer on another CPU, reprogramming is
902 * skipped. The interrupt event on this CPU is fired and
903 * reprogramming happens in the interrupt handler. This is a
904 * rare case and less expensive than a smp call.
906 debug_deactivate(timer);
907 timer_stats_hrtimer_clear_start_info(timer);
908 reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
910 * We must preserve the CALLBACK state flag here,
911 * otherwise we could move the timer base in
912 * switch_hrtimer_base.
914 state = timer->state & HRTIMER_STATE_CALLBACK;
915 __remove_hrtimer(timer, base, state, reprogram);
922 * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
923 * @timer: the timer to be added
925 * @delta_ns: "slack" range for the timer
926 * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or
927 * relative (HRTIMER_MODE_REL)
929 void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
930 unsigned long delta_ns, const enum hrtimer_mode mode)
932 struct hrtimer_clock_base *base, *new_base;
936 base = lock_hrtimer_base(timer, &flags);
938 /* Remove an active timer from the queue: */
939 remove_hrtimer(timer, base);
941 if (mode & HRTIMER_MODE_REL) {
942 tim = ktime_add_safe(tim, base->get_time());
944 * CONFIG_TIME_LOW_RES is a temporary way for architectures
945 * to signal that they simply return xtime in
946 * do_gettimeoffset(). In this case we want to round up by
947 * resolution when starting a relative timer, to avoid short
948 * timeouts. This will go away with the GTOD framework.
950 #ifdef CONFIG_TIME_LOW_RES
951 tim = ktime_add_safe(tim, ktime_set(0, hrtimer_resolution));
955 hrtimer_set_expires_range_ns(timer, tim, delta_ns);
957 /* Switch the timer base, if necessary: */
958 new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
960 timer_stats_hrtimer_set_start_info(timer);
962 leftmost = enqueue_hrtimer(timer, new_base);
966 if (!hrtimer_is_hres_active(timer)) {
968 * Kick to reschedule the next tick to handle the new timer
969 * on dynticks target.
971 wake_up_nohz_cpu(new_base->cpu_base->cpu);
973 hrtimer_reprogram(timer, new_base);
976 unlock_hrtimer_base(timer, &flags);
978 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
981 * hrtimer_try_to_cancel - try to deactivate a timer
982 * @timer: hrtimer to stop
985 * 0 when the timer was not active
986 * 1 when the timer was active
987 * -1 when the timer is currently excuting the callback function and
990 int hrtimer_try_to_cancel(struct hrtimer *timer)
992 struct hrtimer_clock_base *base;
997 * Check lockless first. If the timer is not active (neither
998 * enqueued nor running the callback, nothing to do here. The
999 * base lock does not serialize against a concurrent enqueue,
1000 * so we can avoid taking it.
1002 if (!hrtimer_active(timer))
1005 base = lock_hrtimer_base(timer, &flags);
1007 if (!hrtimer_callback_running(timer))
1008 ret = remove_hrtimer(timer, base);
1010 unlock_hrtimer_base(timer, &flags);
1015 EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
1018 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
1019 * @timer: the timer to be cancelled
1022 * 0 when the timer was not active
1023 * 1 when the timer was active
1025 int hrtimer_cancel(struct hrtimer *timer)
1028 int ret = hrtimer_try_to_cancel(timer);
1035 EXPORT_SYMBOL_GPL(hrtimer_cancel);
1038 * hrtimer_get_remaining - get remaining time for the timer
1039 * @timer: the timer to read
1041 ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
1043 unsigned long flags;
1046 lock_hrtimer_base(timer, &flags);
1047 rem = hrtimer_expires_remaining(timer);
1048 unlock_hrtimer_base(timer, &flags);
1052 EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
1054 #ifdef CONFIG_NO_HZ_COMMON
1056 * hrtimer_get_next_event - get the time until next expiry event
1058 * Returns the next expiry time or KTIME_MAX if no timer is pending.
1060 u64 hrtimer_get_next_event(void)
1062 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1063 u64 expires = KTIME_MAX;
1064 unsigned long flags;
1066 raw_spin_lock_irqsave(&cpu_base->lock, flags);
1068 if (!__hrtimer_hres_active(cpu_base))
1069 expires = __hrtimer_get_next_event(cpu_base).tv64;
1071 raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
1077 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1078 enum hrtimer_mode mode)
1080 struct hrtimer_cpu_base *cpu_base;
1083 memset(timer, 0, sizeof(struct hrtimer));
1085 cpu_base = raw_cpu_ptr(&hrtimer_bases);
1087 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
1088 clock_id = CLOCK_MONOTONIC;
1090 base = hrtimer_clockid_to_base(clock_id);
1091 timer->base = &cpu_base->clock_base[base];
1092 timerqueue_init(&timer->node);
1094 #ifdef CONFIG_TIMER_STATS
1095 timer->start_site = NULL;
1096 timer->start_pid = -1;
1097 memset(timer->start_comm, 0, TASK_COMM_LEN);
1102 * hrtimer_init - initialize a timer to the given clock
1103 * @timer: the timer to be initialized
1104 * @clock_id: the clock to be used
1105 * @mode: timer mode abs/rel
1107 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1108 enum hrtimer_mode mode)
1110 debug_init(timer, clock_id, mode);
1111 __hrtimer_init(timer, clock_id, mode);
1113 EXPORT_SYMBOL_GPL(hrtimer_init);
1115 static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
1116 struct hrtimer_clock_base *base,
1117 struct hrtimer *timer, ktime_t *now)
1119 enum hrtimer_restart (*fn)(struct hrtimer *);
1122 WARN_ON(!irqs_disabled());
1124 debug_deactivate(timer);
1125 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1126 timer_stats_account_hrtimer(timer);
1127 fn = timer->function;
1130 * Because we run timers from hardirq context, there is no chance
1131 * they get migrated to another cpu, therefore its safe to unlock
1134 raw_spin_unlock(&cpu_base->lock);
1135 trace_hrtimer_expire_entry(timer, now);
1136 restart = fn(timer);
1137 trace_hrtimer_expire_exit(timer);
1138 raw_spin_lock(&cpu_base->lock);
1141 * Note: We clear the CALLBACK bit after enqueue_hrtimer and
1142 * we do not reprogramm the event hardware. Happens either in
1143 * hrtimer_start_range_ns() or in hrtimer_interrupt()
1145 * Note: Because we dropped the cpu_base->lock above,
1146 * hrtimer_start_range_ns() can have popped in and enqueued the timer
1149 if (restart != HRTIMER_NORESTART &&
1150 !(timer->state & HRTIMER_STATE_ENQUEUED))
1151 enqueue_hrtimer(timer, base);
1153 WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK));
1155 timer->state &= ~HRTIMER_STATE_CALLBACK;
1158 static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now)
1160 struct hrtimer_clock_base *base = cpu_base->clock_base;
1161 unsigned int active = cpu_base->active_bases;
1163 for (; active; base++, active >>= 1) {
1164 struct timerqueue_node *node;
1167 if (!(active & 0x01))
1170 basenow = ktime_add(now, base->offset);
1172 while ((node = timerqueue_getnext(&base->active))) {
1173 struct hrtimer *timer;
1175 timer = container_of(node, struct hrtimer, node);
1178 * The immediate goal for using the softexpires is
1179 * minimizing wakeups, not running timers at the
1180 * earliest interrupt after their soft expiration.
1181 * This allows us to avoid using a Priority Search
1182 * Tree, which can answer a stabbing querry for
1183 * overlapping intervals and instead use the simple
1184 * BST we already have.
1185 * We don't add extra wakeups by delaying timers that
1186 * are right-of a not yet expired timer, because that
1187 * timer will have to trigger a wakeup anyway.
1189 if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer))
1192 __run_hrtimer(cpu_base, base, timer, &basenow);
1197 #ifdef CONFIG_HIGH_RES_TIMERS
1200 * High resolution timer interrupt
1201 * Called with interrupts disabled
1203 void hrtimer_interrupt(struct clock_event_device *dev)
1205 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1206 ktime_t expires_next, now, entry_time, delta;
1209 BUG_ON(!cpu_base->hres_active);
1210 cpu_base->nr_events++;
1211 dev->next_event.tv64 = KTIME_MAX;
1213 raw_spin_lock(&cpu_base->lock);
1214 entry_time = now = hrtimer_update_base(cpu_base);
1216 cpu_base->in_hrtirq = 1;
1218 * We set expires_next to KTIME_MAX here with cpu_base->lock
1219 * held to prevent that a timer is enqueued in our queue via
1220 * the migration code. This does not affect enqueueing of
1221 * timers which run their callback and need to be requeued on
1224 cpu_base->expires_next.tv64 = KTIME_MAX;
1226 __hrtimer_run_queues(cpu_base, now);
1228 /* Reevaluate the clock bases for the next expiry */
1229 expires_next = __hrtimer_get_next_event(cpu_base);
1231 * Store the new expiry value so the migration code can verify
1234 cpu_base->expires_next = expires_next;
1235 cpu_base->in_hrtirq = 0;
1236 raw_spin_unlock(&cpu_base->lock);
1238 /* Reprogramming necessary ? */
1239 if (!tick_program_event(expires_next, 0)) {
1240 cpu_base->hang_detected = 0;
1245 * The next timer was already expired due to:
1247 * - long lasting callbacks
1248 * - being scheduled away when running in a VM
1250 * We need to prevent that we loop forever in the hrtimer
1251 * interrupt routine. We give it 3 attempts to avoid
1252 * overreacting on some spurious event.
1254 * Acquire base lock for updating the offsets and retrieving
1257 raw_spin_lock(&cpu_base->lock);
1258 now = hrtimer_update_base(cpu_base);
1259 cpu_base->nr_retries++;
1263 * Give the system a chance to do something else than looping
1264 * here. We stored the entry time, so we know exactly how long
1265 * we spent here. We schedule the next event this amount of
1268 cpu_base->nr_hangs++;
1269 cpu_base->hang_detected = 1;
1270 raw_spin_unlock(&cpu_base->lock);
1271 delta = ktime_sub(now, entry_time);
1272 if ((unsigned int)delta.tv64 > cpu_base->max_hang_time)
1273 cpu_base->max_hang_time = (unsigned int) delta.tv64;
1275 * Limit it to a sensible value as we enforce a longer
1276 * delay. Give the CPU at least 100ms to catch up.
1278 if (delta.tv64 > 100 * NSEC_PER_MSEC)
1279 expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC);
1281 expires_next = ktime_add(now, delta);
1282 tick_program_event(expires_next, 1);
1283 printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
1284 ktime_to_ns(delta));
1288 * local version of hrtimer_peek_ahead_timers() called with interrupts
1291 static inline void __hrtimer_peek_ahead_timers(void)
1293 struct tick_device *td;
1295 if (!hrtimer_hres_active())
1298 td = this_cpu_ptr(&tick_cpu_device);
1299 if (td && td->evtdev)
1300 hrtimer_interrupt(td->evtdev);
1303 #else /* CONFIG_HIGH_RES_TIMERS */
1305 static inline void __hrtimer_peek_ahead_timers(void) { }
1307 #endif /* !CONFIG_HIGH_RES_TIMERS */
1310 * Called from run_local_timers in hardirq context every jiffy
1312 void hrtimer_run_queues(void)
1314 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1317 if (__hrtimer_hres_active(cpu_base))
1321 * This _is_ ugly: We have to check periodically, whether we
1322 * can switch to highres and / or nohz mode. The clocksource
1323 * switch happens with xtime_lock held. Notification from
1324 * there only sets the check bit in the tick_oneshot code,
1325 * otherwise we might deadlock vs. xtime_lock.
1327 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) {
1328 hrtimer_switch_to_hres();
1332 raw_spin_lock(&cpu_base->lock);
1333 now = hrtimer_update_base(cpu_base);
1334 __hrtimer_run_queues(cpu_base, now);
1335 raw_spin_unlock(&cpu_base->lock);
1339 * Sleep related functions:
1341 static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
1343 struct hrtimer_sleeper *t =
1344 container_of(timer, struct hrtimer_sleeper, timer);
1345 struct task_struct *task = t->task;
1349 wake_up_process(task);
1351 return HRTIMER_NORESTART;
1354 void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
1356 sl->timer.function = hrtimer_wakeup;
1359 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
1361 static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
1363 hrtimer_init_sleeper(t, current);
1366 set_current_state(TASK_INTERRUPTIBLE);
1367 hrtimer_start_expires(&t->timer, mode);
1369 if (likely(t->task))
1370 freezable_schedule();
1372 hrtimer_cancel(&t->timer);
1373 mode = HRTIMER_MODE_ABS;
1375 } while (t->task && !signal_pending(current));
1377 __set_current_state(TASK_RUNNING);
1379 return t->task == NULL;
1382 static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
1384 struct timespec rmt;
1387 rem = hrtimer_expires_remaining(timer);
1390 rmt = ktime_to_timespec(rem);
1392 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1398 long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1400 struct hrtimer_sleeper t;
1401 struct timespec __user *rmtp;
1404 hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
1406 hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
1408 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1411 rmtp = restart->nanosleep.rmtp;
1413 ret = update_rmtp(&t.timer, rmtp);
1418 /* The other values in restart are already filled in */
1419 ret = -ERESTART_RESTARTBLOCK;
1421 destroy_hrtimer_on_stack(&t.timer);
1425 long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1426 const enum hrtimer_mode mode, const clockid_t clockid)
1428 struct restart_block *restart;
1429 struct hrtimer_sleeper t;
1431 unsigned long slack;
1433 slack = current->timer_slack_ns;
1434 if (dl_task(current) || rt_task(current))
1437 hrtimer_init_on_stack(&t.timer, clockid, mode);
1438 hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1439 if (do_nanosleep(&t, mode))
1442 /* Absolute timers do not update the rmtp value and restart: */
1443 if (mode == HRTIMER_MODE_ABS) {
1444 ret = -ERESTARTNOHAND;
1449 ret = update_rmtp(&t.timer, rmtp);
1454 restart = ¤t->restart_block;
1455 restart->fn = hrtimer_nanosleep_restart;
1456 restart->nanosleep.clockid = t.timer.base->clockid;
1457 restart->nanosleep.rmtp = rmtp;
1458 restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
1460 ret = -ERESTART_RESTARTBLOCK;
1462 destroy_hrtimer_on_stack(&t.timer);
1466 SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
1467 struct timespec __user *, rmtp)
1471 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1474 if (!timespec_valid(&tu))
1477 return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
1481 * Functions related to boot-time initialization:
1483 static void init_hrtimers_cpu(int cpu)
1485 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
1488 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1489 cpu_base->clock_base[i].cpu_base = cpu_base;
1490 timerqueue_init_head(&cpu_base->clock_base[i].active);
1493 cpu_base->cpu = cpu;
1494 hrtimer_init_hres(cpu_base);
1497 #ifdef CONFIG_HOTPLUG_CPU
1499 static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1500 struct hrtimer_clock_base *new_base)
1502 struct hrtimer *timer;
1503 struct timerqueue_node *node;
1505 while ((node = timerqueue_getnext(&old_base->active))) {
1506 timer = container_of(node, struct hrtimer, node);
1507 BUG_ON(hrtimer_callback_running(timer));
1508 debug_deactivate(timer);
1511 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
1512 * timer could be seen as !active and just vanish away
1513 * under us on another CPU
1515 __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
1516 timer->base = new_base;
1518 * Enqueue the timers on the new cpu. This does not
1519 * reprogram the event device in case the timer
1520 * expires before the earliest on this CPU, but we run
1521 * hrtimer_interrupt after we migrated everything to
1522 * sort out already expired timers and reprogram the
1525 enqueue_hrtimer(timer, new_base);
1527 /* Clear the migration state bit */
1528 timer->state &= ~HRTIMER_STATE_MIGRATE;
1532 static void migrate_hrtimers(int scpu)
1534 struct hrtimer_cpu_base *old_base, *new_base;
1537 BUG_ON(cpu_online(scpu));
1538 tick_cancel_sched_timer(scpu);
1540 local_irq_disable();
1541 old_base = &per_cpu(hrtimer_bases, scpu);
1542 new_base = this_cpu_ptr(&hrtimer_bases);
1544 * The caller is globally serialized and nobody else
1545 * takes two locks at once, deadlock is not possible.
1547 raw_spin_lock(&new_base->lock);
1548 raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1550 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1551 migrate_hrtimer_list(&old_base->clock_base[i],
1552 &new_base->clock_base[i]);
1555 raw_spin_unlock(&old_base->lock);
1556 raw_spin_unlock(&new_base->lock);
1558 /* Check, if we got expired work to do */
1559 __hrtimer_peek_ahead_timers();
1563 #endif /* CONFIG_HOTPLUG_CPU */
1565 static int hrtimer_cpu_notify(struct notifier_block *self,
1566 unsigned long action, void *hcpu)
1568 int scpu = (long)hcpu;
1572 case CPU_UP_PREPARE:
1573 case CPU_UP_PREPARE_FROZEN:
1574 init_hrtimers_cpu(scpu);
1577 #ifdef CONFIG_HOTPLUG_CPU
1579 case CPU_DEAD_FROZEN:
1580 migrate_hrtimers(scpu);
1591 static struct notifier_block hrtimers_nb = {
1592 .notifier_call = hrtimer_cpu_notify,
1595 void __init hrtimers_init(void)
1597 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1598 (void *)(long)smp_processor_id());
1599 register_cpu_notifier(&hrtimers_nb);
1603 * schedule_hrtimeout_range_clock - sleep until timeout
1604 * @expires: timeout value (ktime_t)
1605 * @delta: slack in expires timeout (ktime_t)
1606 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1607 * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME
1610 schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
1611 const enum hrtimer_mode mode, int clock)
1613 struct hrtimer_sleeper t;
1616 * Optimize when a zero timeout value is given. It does not
1617 * matter whether this is an absolute or a relative time.
1619 if (expires && !expires->tv64) {
1620 __set_current_state(TASK_RUNNING);
1625 * A NULL parameter means "infinite"
1632 hrtimer_init_on_stack(&t.timer, clock, mode);
1633 hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
1635 hrtimer_init_sleeper(&t, current);
1637 hrtimer_start_expires(&t.timer, mode);
1642 hrtimer_cancel(&t.timer);
1643 destroy_hrtimer_on_stack(&t.timer);
1645 __set_current_state(TASK_RUNNING);
1647 return !t.task ? 0 : -EINTR;
1651 * schedule_hrtimeout_range - sleep until timeout
1652 * @expires: timeout value (ktime_t)
1653 * @delta: slack in expires timeout (ktime_t)
1654 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1656 * Make the current task sleep until the given expiry time has
1657 * elapsed. The routine will return immediately unless
1658 * the current task state has been set (see set_current_state()).
1660 * The @delta argument gives the kernel the freedom to schedule the
1661 * actual wakeup to a time that is both power and performance friendly.
1662 * The kernel give the normal best effort behavior for "@expires+@delta",
1663 * but may decide to fire the timer earlier, but no earlier than @expires.
1665 * You can set the task state as follows -
1667 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1668 * pass before the routine returns.
1670 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1671 * delivered to the current task.
1673 * The current task state is guaranteed to be TASK_RUNNING when this
1676 * Returns 0 when the timer has expired otherwise -EINTR
1678 int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
1679 const enum hrtimer_mode mode)
1681 return schedule_hrtimeout_range_clock(expires, delta, mode,
1684 EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
1687 * schedule_hrtimeout - sleep until timeout
1688 * @expires: timeout value (ktime_t)
1689 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1691 * Make the current task sleep until the given expiry time has
1692 * elapsed. The routine will return immediately unless
1693 * the current task state has been set (see set_current_state()).
1695 * You can set the task state as follows -
1697 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1698 * pass before the routine returns.
1700 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1701 * delivered to the current task.
1703 * The current task state is guaranteed to be TASK_RUNNING when this
1706 * Returns 0 when the timer has expired otherwise -EINTR
1708 int __sched schedule_hrtimeout(ktime_t *expires,
1709 const enum hrtimer_mode mode)
1711 return schedule_hrtimeout_range(expires, 0, mode);
1713 EXPORT_SYMBOL_GPL(schedule_hrtimeout);