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 if (cpu_base
->expires_next
.tv64
!= KTIME_MAX
)
554 tick_program_event(cpu_base
->expires_next
, 1);
558 * When a timer is enqueued and expires earlier than the already enqueued
559 * timers, we have to check, whether it expires earlier than the timer for
560 * which the clock event device was armed.
562 * Called with interrupts disabled and base->cpu_base.lock held
564 static void hrtimer_reprogram(struct hrtimer
*timer
,
565 struct hrtimer_clock_base
*base
)
567 struct hrtimer_cpu_base
*cpu_base
= this_cpu_ptr(&hrtimer_bases
);
568 ktime_t expires
= ktime_sub(hrtimer_get_expires(timer
), base
->offset
);
570 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer
) < 0);
573 * If the timer is not on the current cpu, we cannot reprogram
574 * the other cpus clock event device.
576 if (base
->cpu_base
!= cpu_base
)
580 * If the hrtimer interrupt is running, then it will
581 * reevaluate the clock bases and reprogram the clock event
582 * device. The callbacks are always executed in hard interrupt
583 * context so we don't need an extra check for a running
586 if (cpu_base
->in_hrtirq
)
590 * CLOCK_REALTIME timer might be requested with an absolute
591 * expiry time which is less than base->offset. Set it to 0.
593 if (expires
.tv64
< 0)
596 if (expires
.tv64
>= cpu_base
->expires_next
.tv64
)
599 /* Update the pointer to the next expiring timer */
600 cpu_base
->next_timer
= timer
;
603 * If a hang was detected in the last timer interrupt then we
604 * do not schedule a timer which is earlier than the expiry
605 * which we enforced in the hang detection. We want the system
608 if (cpu_base
->hang_detected
)
612 * Program the timer hardware. We enforce the expiry for
613 * events which are already in the past.
615 cpu_base
->expires_next
= expires
;
616 tick_program_event(expires
, 1);
620 * Initialize the high resolution related parts of cpu_base
622 static inline void hrtimer_init_hres(struct hrtimer_cpu_base
*base
)
624 base
->expires_next
.tv64
= KTIME_MAX
;
625 base
->hres_active
= 0;
629 * Retrigger next event is called after clock was set
631 * Called with interrupts disabled via on_each_cpu()
633 static void retrigger_next_event(void *arg
)
635 struct hrtimer_cpu_base
*base
= this_cpu_ptr(&hrtimer_bases
);
637 if (!base
->hres_active
)
640 raw_spin_lock(&base
->lock
);
641 hrtimer_update_base(base
);
642 hrtimer_force_reprogram(base
, 0);
643 raw_spin_unlock(&base
->lock
);
647 * Switch to high resolution mode
649 static int hrtimer_switch_to_hres(void)
651 struct hrtimer_cpu_base
*base
= this_cpu_ptr(&hrtimer_bases
);
653 if (tick_init_highres()) {
654 printk(KERN_WARNING
"Could not switch to high resolution "
655 "mode on CPU %d\n", base
->cpu
);
658 base
->hres_active
= 1;
659 hrtimer_resolution
= HIGH_RES_NSEC
;
661 tick_setup_sched_timer();
662 /* "Retrigger" the interrupt to get things going */
663 retrigger_next_event(NULL
);
667 static void clock_was_set_work(struct work_struct
*work
)
672 static DECLARE_WORK(hrtimer_work
, clock_was_set_work
);
675 * Called from timekeeping and resume code to reprogramm the hrtimer
676 * interrupt device on all cpus.
678 void clock_was_set_delayed(void)
680 schedule_work(&hrtimer_work
);
685 static inline int __hrtimer_hres_active(struct hrtimer_cpu_base
*b
) { return 0; }
686 static inline int hrtimer_hres_active(void) { return 0; }
687 static inline int hrtimer_is_hres_enabled(void) { return 0; }
688 static inline int hrtimer_switch_to_hres(void) { return 0; }
690 hrtimer_force_reprogram(struct hrtimer_cpu_base
*base
, int skip_equal
) { }
691 static inline int hrtimer_reprogram(struct hrtimer
*timer
,
692 struct hrtimer_clock_base
*base
)
696 static inline void hrtimer_init_hres(struct hrtimer_cpu_base
*base
) { }
697 static inline void retrigger_next_event(void *arg
) { }
699 #endif /* CONFIG_HIGH_RES_TIMERS */
702 * Clock realtime was set
704 * Change the offset of the realtime clock vs. the monotonic
707 * We might have to reprogram the high resolution timer interrupt. On
708 * SMP we call the architecture specific code to retrigger _all_ high
709 * resolution timer interrupts. On UP we just disable interrupts and
710 * call the high resolution interrupt code.
712 void clock_was_set(void)
714 #ifdef CONFIG_HIGH_RES_TIMERS
715 /* Retrigger the CPU local events everywhere */
716 on_each_cpu(retrigger_next_event
, NULL
, 1);
718 timerfd_clock_was_set();
722 * During resume we might have to reprogram the high resolution timer
723 * interrupt on all online CPUs. However, all other CPUs will be
724 * stopped with IRQs interrupts disabled so the clock_was_set() call
727 void hrtimers_resume(void)
729 WARN_ONCE(!irqs_disabled(),
730 KERN_INFO
"hrtimers_resume() called with IRQs enabled!");
732 /* Retrigger on the local CPU */
733 retrigger_next_event(NULL
);
734 /* And schedule a retrigger for all others */
735 clock_was_set_delayed();
738 static inline void timer_stats_hrtimer_set_start_info(struct hrtimer
*timer
)
740 #ifdef CONFIG_TIMER_STATS
741 if (timer
->start_site
)
743 timer
->start_site
= __builtin_return_address(0);
744 memcpy(timer
->start_comm
, current
->comm
, TASK_COMM_LEN
);
745 timer
->start_pid
= current
->pid
;
749 static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer
*timer
)
751 #ifdef CONFIG_TIMER_STATS
752 timer
->start_site
= NULL
;
756 static inline void timer_stats_account_hrtimer(struct hrtimer
*timer
)
758 #ifdef CONFIG_TIMER_STATS
759 if (likely(!timer_stats_active
))
761 timer_stats_update_stats(timer
, timer
->start_pid
, timer
->start_site
,
762 timer
->function
, timer
->start_comm
, 0);
767 * Counterpart to lock_hrtimer_base above:
770 void unlock_hrtimer_base(const struct hrtimer
*timer
, unsigned long *flags
)
772 raw_spin_unlock_irqrestore(&timer
->base
->cpu_base
->lock
, *flags
);
776 * hrtimer_forward - forward the timer expiry
777 * @timer: hrtimer to forward
778 * @now: forward past this time
779 * @interval: the interval to forward
781 * Forward the timer expiry so it will expire in the future.
782 * Returns the number of overruns.
784 * Can be safely called from the callback function of @timer. If
785 * called from other contexts @timer must neither be enqueued nor
786 * running the callback and the caller needs to take care of
789 * Note: This only updates the timer expiry value and does not requeue
792 u64
hrtimer_forward(struct hrtimer
*timer
, ktime_t now
, ktime_t interval
)
797 delta
= ktime_sub(now
, hrtimer_get_expires(timer
));
802 if (interval
.tv64
< hrtimer_resolution
)
803 interval
.tv64
= hrtimer_resolution
;
805 if (unlikely(delta
.tv64
>= interval
.tv64
)) {
806 s64 incr
= ktime_to_ns(interval
);
808 orun
= ktime_divns(delta
, incr
);
809 hrtimer_add_expires_ns(timer
, incr
* orun
);
810 if (hrtimer_get_expires_tv64(timer
) > now
.tv64
)
813 * This (and the ktime_add() below) is the
814 * correction for exact:
818 hrtimer_add_expires(timer
, interval
);
822 EXPORT_SYMBOL_GPL(hrtimer_forward
);
825 * enqueue_hrtimer - internal function to (re)start a timer
827 * The timer is inserted in expiry order. Insertion into the
828 * red black tree is O(log(n)). Must hold the base lock.
830 * Returns 1 when the new timer is the leftmost timer in the tree.
832 static int enqueue_hrtimer(struct hrtimer
*timer
,
833 struct hrtimer_clock_base
*base
)
835 debug_activate(timer
);
837 base
->cpu_base
->active_bases
|= 1 << base
->index
;
840 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
841 * state of a possibly running callback.
843 timer
->state
|= HRTIMER_STATE_ENQUEUED
;
845 return timerqueue_add(&base
->active
, &timer
->node
);
849 * __remove_hrtimer - internal function to remove a timer
851 * Caller must hold the base lock.
853 * High resolution timer mode reprograms the clock event device when the
854 * timer is the one which expires next. The caller can disable this by setting
855 * reprogram to zero. This is useful, when the context does a reprogramming
856 * anyway (e.g. timer interrupt)
858 static void __remove_hrtimer(struct hrtimer
*timer
,
859 struct hrtimer_clock_base
*base
,
860 unsigned long newstate
, int reprogram
)
862 struct hrtimer_cpu_base
*cpu_base
= base
->cpu_base
;
863 unsigned int state
= timer
->state
;
865 timer
->state
= newstate
;
866 if (!(state
& HRTIMER_STATE_ENQUEUED
))
869 if (!timerqueue_del(&base
->active
, &timer
->node
))
870 cpu_base
->active_bases
&= ~(1 << base
->index
);
872 #ifdef CONFIG_HIGH_RES_TIMERS
874 * Note: If reprogram is false we do not update
875 * cpu_base->next_timer. This happens when we remove the first
876 * timer on a remote cpu. No harm as we never dereference
877 * cpu_base->next_timer. So the worst thing what can happen is
878 * an superflous call to hrtimer_force_reprogram() on the
879 * remote cpu later on if the same timer gets enqueued again.
881 if (reprogram
&& timer
== cpu_base
->next_timer
)
882 hrtimer_force_reprogram(cpu_base
, 1);
887 * remove hrtimer, called with base lock held
890 remove_hrtimer(struct hrtimer
*timer
, struct hrtimer_clock_base
*base
)
892 if (hrtimer_is_queued(timer
)) {
897 * Remove the timer and force reprogramming when high
898 * resolution mode is active and the timer is on the current
899 * CPU. If we remove a timer on another CPU, reprogramming is
900 * skipped. The interrupt event on this CPU is fired and
901 * reprogramming happens in the interrupt handler. This is a
902 * rare case and less expensive than a smp call.
904 debug_deactivate(timer
);
905 timer_stats_hrtimer_clear_start_info(timer
);
906 reprogram
= base
->cpu_base
== this_cpu_ptr(&hrtimer_bases
);
908 * We must preserve the CALLBACK state flag here,
909 * otherwise we could move the timer base in
910 * switch_hrtimer_base.
912 state
= timer
->state
& HRTIMER_STATE_CALLBACK
;
913 __remove_hrtimer(timer
, base
, state
, reprogram
);
920 * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
921 * @timer: the timer to be added
923 * @delta_ns: "slack" range for the timer
924 * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or
925 * relative (HRTIMER_MODE_REL)
927 void hrtimer_start_range_ns(struct hrtimer
*timer
, ktime_t tim
,
928 unsigned long delta_ns
, const enum hrtimer_mode mode
)
930 struct hrtimer_clock_base
*base
, *new_base
;
934 base
= lock_hrtimer_base(timer
, &flags
);
936 /* Remove an active timer from the queue: */
937 remove_hrtimer(timer
, base
);
939 if (mode
& HRTIMER_MODE_REL
) {
940 tim
= ktime_add_safe(tim
, base
->get_time());
942 * CONFIG_TIME_LOW_RES is a temporary way for architectures
943 * to signal that they simply return xtime in
944 * do_gettimeoffset(). In this case we want to round up by
945 * resolution when starting a relative timer, to avoid short
946 * timeouts. This will go away with the GTOD framework.
948 #ifdef CONFIG_TIME_LOW_RES
949 tim
= ktime_add_safe(tim
, ktime_set(0, hrtimer_resolution
));
953 hrtimer_set_expires_range_ns(timer
, tim
, delta_ns
);
955 /* Switch the timer base, if necessary: */
956 new_base
= switch_hrtimer_base(timer
, base
, mode
& HRTIMER_MODE_PINNED
);
958 timer_stats_hrtimer_set_start_info(timer
);
960 leftmost
= enqueue_hrtimer(timer
, new_base
);
964 if (!hrtimer_is_hres_active(timer
)) {
966 * Kick to reschedule the next tick to handle the new timer
967 * on dynticks target.
969 wake_up_nohz_cpu(new_base
->cpu_base
->cpu
);
971 hrtimer_reprogram(timer
, new_base
);
974 unlock_hrtimer_base(timer
, &flags
);
976 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns
);
979 * hrtimer_try_to_cancel - try to deactivate a timer
980 * @timer: hrtimer to stop
983 * 0 when the timer was not active
984 * 1 when the timer was active
985 * -1 when the timer is currently excuting the callback function and
988 int hrtimer_try_to_cancel(struct hrtimer
*timer
)
990 struct hrtimer_clock_base
*base
;
994 base
= lock_hrtimer_base(timer
, &flags
);
996 if (!hrtimer_callback_running(timer
))
997 ret
= remove_hrtimer(timer
, base
);
999 unlock_hrtimer_base(timer
, &flags
);
1004 EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel
);
1007 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
1008 * @timer: the timer to be cancelled
1011 * 0 when the timer was not active
1012 * 1 when the timer was active
1014 int hrtimer_cancel(struct hrtimer
*timer
)
1017 int ret
= hrtimer_try_to_cancel(timer
);
1024 EXPORT_SYMBOL_GPL(hrtimer_cancel
);
1027 * hrtimer_get_remaining - get remaining time for the timer
1028 * @timer: the timer to read
1030 ktime_t
hrtimer_get_remaining(const struct hrtimer
*timer
)
1032 unsigned long flags
;
1035 lock_hrtimer_base(timer
, &flags
);
1036 rem
= hrtimer_expires_remaining(timer
);
1037 unlock_hrtimer_base(timer
, &flags
);
1041 EXPORT_SYMBOL_GPL(hrtimer_get_remaining
);
1043 #ifdef CONFIG_NO_HZ_COMMON
1045 * hrtimer_get_next_event - get the time until next expiry event
1047 * Returns the next expiry time or KTIME_MAX if no timer is pending.
1049 u64
hrtimer_get_next_event(void)
1051 struct hrtimer_cpu_base
*cpu_base
= this_cpu_ptr(&hrtimer_bases
);
1052 u64 expires
= KTIME_MAX
;
1053 unsigned long flags
;
1055 raw_spin_lock_irqsave(&cpu_base
->lock
, flags
);
1057 if (!__hrtimer_hres_active(cpu_base
))
1058 expires
= __hrtimer_get_next_event(cpu_base
).tv64
;
1060 raw_spin_unlock_irqrestore(&cpu_base
->lock
, flags
);
1066 static void __hrtimer_init(struct hrtimer
*timer
, clockid_t clock_id
,
1067 enum hrtimer_mode mode
)
1069 struct hrtimer_cpu_base
*cpu_base
;
1072 memset(timer
, 0, sizeof(struct hrtimer
));
1074 cpu_base
= raw_cpu_ptr(&hrtimer_bases
);
1076 if (clock_id
== CLOCK_REALTIME
&& mode
!= HRTIMER_MODE_ABS
)
1077 clock_id
= CLOCK_MONOTONIC
;
1079 base
= hrtimer_clockid_to_base(clock_id
);
1080 timer
->base
= &cpu_base
->clock_base
[base
];
1081 timerqueue_init(&timer
->node
);
1083 #ifdef CONFIG_TIMER_STATS
1084 timer
->start_site
= NULL
;
1085 timer
->start_pid
= -1;
1086 memset(timer
->start_comm
, 0, TASK_COMM_LEN
);
1091 * hrtimer_init - initialize a timer to the given clock
1092 * @timer: the timer to be initialized
1093 * @clock_id: the clock to be used
1094 * @mode: timer mode abs/rel
1096 void hrtimer_init(struct hrtimer
*timer
, clockid_t clock_id
,
1097 enum hrtimer_mode mode
)
1099 debug_init(timer
, clock_id
, mode
);
1100 __hrtimer_init(timer
, clock_id
, mode
);
1102 EXPORT_SYMBOL_GPL(hrtimer_init
);
1104 static void __run_hrtimer(struct hrtimer_cpu_base
*cpu_base
,
1105 struct hrtimer_clock_base
*base
,
1106 struct hrtimer
*timer
, ktime_t
*now
)
1108 enum hrtimer_restart (*fn
)(struct hrtimer
*);
1111 WARN_ON(!irqs_disabled());
1113 debug_deactivate(timer
);
1114 __remove_hrtimer(timer
, base
, HRTIMER_STATE_CALLBACK
, 0);
1115 timer_stats_account_hrtimer(timer
);
1116 fn
= timer
->function
;
1119 * Because we run timers from hardirq context, there is no chance
1120 * they get migrated to another cpu, therefore its safe to unlock
1123 raw_spin_unlock(&cpu_base
->lock
);
1124 trace_hrtimer_expire_entry(timer
, now
);
1125 restart
= fn(timer
);
1126 trace_hrtimer_expire_exit(timer
);
1127 raw_spin_lock(&cpu_base
->lock
);
1130 * Note: We clear the CALLBACK bit after enqueue_hrtimer and
1131 * we do not reprogramm the event hardware. Happens either in
1132 * hrtimer_start_range_ns() or in hrtimer_interrupt()
1134 if (restart
!= HRTIMER_NORESTART
) {
1135 BUG_ON(timer
->state
!= HRTIMER_STATE_CALLBACK
);
1136 enqueue_hrtimer(timer
, base
);
1139 WARN_ON_ONCE(!(timer
->state
& HRTIMER_STATE_CALLBACK
));
1141 timer
->state
&= ~HRTIMER_STATE_CALLBACK
;
1144 static void __hrtimer_run_queues(struct hrtimer_cpu_base
*cpu_base
, ktime_t now
)
1146 struct hrtimer_clock_base
*base
= cpu_base
->clock_base
;
1147 unsigned int active
= cpu_base
->active_bases
;
1149 for (; active
; base
++, active
>>= 1) {
1150 struct timerqueue_node
*node
;
1153 if (!(active
& 0x01))
1156 basenow
= ktime_add(now
, base
->offset
);
1158 while ((node
= timerqueue_getnext(&base
->active
))) {
1159 struct hrtimer
*timer
;
1161 timer
= container_of(node
, struct hrtimer
, node
);
1164 * The immediate goal for using the softexpires is
1165 * minimizing wakeups, not running timers at the
1166 * earliest interrupt after their soft expiration.
1167 * This allows us to avoid using a Priority Search
1168 * Tree, which can answer a stabbing querry for
1169 * overlapping intervals and instead use the simple
1170 * BST we already have.
1171 * We don't add extra wakeups by delaying timers that
1172 * are right-of a not yet expired timer, because that
1173 * timer will have to trigger a wakeup anyway.
1175 if (basenow
.tv64
< hrtimer_get_softexpires_tv64(timer
))
1178 __run_hrtimer(cpu_base
, base
, timer
, &basenow
);
1183 #ifdef CONFIG_HIGH_RES_TIMERS
1186 * High resolution timer interrupt
1187 * Called with interrupts disabled
1189 void hrtimer_interrupt(struct clock_event_device
*dev
)
1191 struct hrtimer_cpu_base
*cpu_base
= this_cpu_ptr(&hrtimer_bases
);
1192 ktime_t expires_next
, now
, entry_time
, delta
;
1195 BUG_ON(!cpu_base
->hres_active
);
1196 cpu_base
->nr_events
++;
1197 dev
->next_event
.tv64
= KTIME_MAX
;
1199 raw_spin_lock(&cpu_base
->lock
);
1200 entry_time
= now
= hrtimer_update_base(cpu_base
);
1202 cpu_base
->in_hrtirq
= 1;
1204 * We set expires_next to KTIME_MAX here with cpu_base->lock
1205 * held to prevent that a timer is enqueued in our queue via
1206 * the migration code. This does not affect enqueueing of
1207 * timers which run their callback and need to be requeued on
1210 cpu_base
->expires_next
.tv64
= KTIME_MAX
;
1212 __hrtimer_run_queues(cpu_base
, now
);
1214 /* Reevaluate the clock bases for the next expiry */
1215 expires_next
= __hrtimer_get_next_event(cpu_base
);
1217 * Store the new expiry value so the migration code can verify
1220 cpu_base
->expires_next
= expires_next
;
1221 cpu_base
->in_hrtirq
= 0;
1222 raw_spin_unlock(&cpu_base
->lock
);
1224 /* Reprogramming necessary ? */
1225 if (expires_next
.tv64
== KTIME_MAX
||
1226 !tick_program_event(expires_next
, 0)) {
1227 cpu_base
->hang_detected
= 0;
1232 * The next timer was already expired due to:
1234 * - long lasting callbacks
1235 * - being scheduled away when running in a VM
1237 * We need to prevent that we loop forever in the hrtimer
1238 * interrupt routine. We give it 3 attempts to avoid
1239 * overreacting on some spurious event.
1241 * Acquire base lock for updating the offsets and retrieving
1244 raw_spin_lock(&cpu_base
->lock
);
1245 now
= hrtimer_update_base(cpu_base
);
1246 cpu_base
->nr_retries
++;
1250 * Give the system a chance to do something else than looping
1251 * here. We stored the entry time, so we know exactly how long
1252 * we spent here. We schedule the next event this amount of
1255 cpu_base
->nr_hangs
++;
1256 cpu_base
->hang_detected
= 1;
1257 raw_spin_unlock(&cpu_base
->lock
);
1258 delta
= ktime_sub(now
, entry_time
);
1259 if ((unsigned int)delta
.tv64
> cpu_base
->max_hang_time
)
1260 cpu_base
->max_hang_time
= (unsigned int) delta
.tv64
;
1262 * Limit it to a sensible value as we enforce a longer
1263 * delay. Give the CPU at least 100ms to catch up.
1265 if (delta
.tv64
> 100 * NSEC_PER_MSEC
)
1266 expires_next
= ktime_add_ns(now
, 100 * NSEC_PER_MSEC
);
1268 expires_next
= ktime_add(now
, delta
);
1269 tick_program_event(expires_next
, 1);
1270 printk_once(KERN_WARNING
"hrtimer: interrupt took %llu ns\n",
1271 ktime_to_ns(delta
));
1275 * local version of hrtimer_peek_ahead_timers() called with interrupts
1278 static inline void __hrtimer_peek_ahead_timers(void)
1280 struct tick_device
*td
;
1282 if (!hrtimer_hres_active())
1285 td
= this_cpu_ptr(&tick_cpu_device
);
1286 if (td
&& td
->evtdev
)
1287 hrtimer_interrupt(td
->evtdev
);
1290 #else /* CONFIG_HIGH_RES_TIMERS */
1292 static inline void __hrtimer_peek_ahead_timers(void) { }
1294 #endif /* !CONFIG_HIGH_RES_TIMERS */
1297 * Called from run_local_timers in hardirq context every jiffy
1299 void hrtimer_run_queues(void)
1301 struct hrtimer_cpu_base
*cpu_base
= this_cpu_ptr(&hrtimer_bases
);
1304 if (__hrtimer_hres_active(cpu_base
))
1308 * This _is_ ugly: We have to check periodically, whether we
1309 * can switch to highres and / or nohz mode. The clocksource
1310 * switch happens with xtime_lock held. Notification from
1311 * there only sets the check bit in the tick_oneshot code,
1312 * otherwise we might deadlock vs. xtime_lock.
1314 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) {
1315 hrtimer_switch_to_hres();
1319 raw_spin_lock(&cpu_base
->lock
);
1320 now
= hrtimer_update_base(cpu_base
);
1321 __hrtimer_run_queues(cpu_base
, now
);
1322 raw_spin_unlock(&cpu_base
->lock
);
1326 * Sleep related functions:
1328 static enum hrtimer_restart
hrtimer_wakeup(struct hrtimer
*timer
)
1330 struct hrtimer_sleeper
*t
=
1331 container_of(timer
, struct hrtimer_sleeper
, timer
);
1332 struct task_struct
*task
= t
->task
;
1336 wake_up_process(task
);
1338 return HRTIMER_NORESTART
;
1341 void hrtimer_init_sleeper(struct hrtimer_sleeper
*sl
, struct task_struct
*task
)
1343 sl
->timer
.function
= hrtimer_wakeup
;
1346 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper
);
1348 static int __sched
do_nanosleep(struct hrtimer_sleeper
*t
, enum hrtimer_mode mode
)
1350 hrtimer_init_sleeper(t
, current
);
1353 set_current_state(TASK_INTERRUPTIBLE
);
1354 hrtimer_start_expires(&t
->timer
, mode
);
1356 if (likely(t
->task
))
1357 freezable_schedule();
1359 hrtimer_cancel(&t
->timer
);
1360 mode
= HRTIMER_MODE_ABS
;
1362 } while (t
->task
&& !signal_pending(current
));
1364 __set_current_state(TASK_RUNNING
);
1366 return t
->task
== NULL
;
1369 static int update_rmtp(struct hrtimer
*timer
, struct timespec __user
*rmtp
)
1371 struct timespec rmt
;
1374 rem
= hrtimer_expires_remaining(timer
);
1377 rmt
= ktime_to_timespec(rem
);
1379 if (copy_to_user(rmtp
, &rmt
, sizeof(*rmtp
)))
1385 long __sched
hrtimer_nanosleep_restart(struct restart_block
*restart
)
1387 struct hrtimer_sleeper t
;
1388 struct timespec __user
*rmtp
;
1391 hrtimer_init_on_stack(&t
.timer
, restart
->nanosleep
.clockid
,
1393 hrtimer_set_expires_tv64(&t
.timer
, restart
->nanosleep
.expires
);
1395 if (do_nanosleep(&t
, HRTIMER_MODE_ABS
))
1398 rmtp
= restart
->nanosleep
.rmtp
;
1400 ret
= update_rmtp(&t
.timer
, rmtp
);
1405 /* The other values in restart are already filled in */
1406 ret
= -ERESTART_RESTARTBLOCK
;
1408 destroy_hrtimer_on_stack(&t
.timer
);
1412 long hrtimer_nanosleep(struct timespec
*rqtp
, struct timespec __user
*rmtp
,
1413 const enum hrtimer_mode mode
, const clockid_t clockid
)
1415 struct restart_block
*restart
;
1416 struct hrtimer_sleeper t
;
1418 unsigned long slack
;
1420 slack
= current
->timer_slack_ns
;
1421 if (dl_task(current
) || rt_task(current
))
1424 hrtimer_init_on_stack(&t
.timer
, clockid
, mode
);
1425 hrtimer_set_expires_range_ns(&t
.timer
, timespec_to_ktime(*rqtp
), slack
);
1426 if (do_nanosleep(&t
, mode
))
1429 /* Absolute timers do not update the rmtp value and restart: */
1430 if (mode
== HRTIMER_MODE_ABS
) {
1431 ret
= -ERESTARTNOHAND
;
1436 ret
= update_rmtp(&t
.timer
, rmtp
);
1441 restart
= ¤t
->restart_block
;
1442 restart
->fn
= hrtimer_nanosleep_restart
;
1443 restart
->nanosleep
.clockid
= t
.timer
.base
->clockid
;
1444 restart
->nanosleep
.rmtp
= rmtp
;
1445 restart
->nanosleep
.expires
= hrtimer_get_expires_tv64(&t
.timer
);
1447 ret
= -ERESTART_RESTARTBLOCK
;
1449 destroy_hrtimer_on_stack(&t
.timer
);
1453 SYSCALL_DEFINE2(nanosleep
, struct timespec __user
*, rqtp
,
1454 struct timespec __user
*, rmtp
)
1458 if (copy_from_user(&tu
, rqtp
, sizeof(tu
)))
1461 if (!timespec_valid(&tu
))
1464 return hrtimer_nanosleep(&tu
, rmtp
, HRTIMER_MODE_REL
, CLOCK_MONOTONIC
);
1468 * Functions related to boot-time initialization:
1470 static void init_hrtimers_cpu(int cpu
)
1472 struct hrtimer_cpu_base
*cpu_base
= &per_cpu(hrtimer_bases
, cpu
);
1475 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++) {
1476 cpu_base
->clock_base
[i
].cpu_base
= cpu_base
;
1477 timerqueue_init_head(&cpu_base
->clock_base
[i
].active
);
1480 cpu_base
->cpu
= cpu
;
1481 hrtimer_init_hres(cpu_base
);
1484 #ifdef CONFIG_HOTPLUG_CPU
1486 static void migrate_hrtimer_list(struct hrtimer_clock_base
*old_base
,
1487 struct hrtimer_clock_base
*new_base
)
1489 struct hrtimer
*timer
;
1490 struct timerqueue_node
*node
;
1492 while ((node
= timerqueue_getnext(&old_base
->active
))) {
1493 timer
= container_of(node
, struct hrtimer
, node
);
1494 BUG_ON(hrtimer_callback_running(timer
));
1495 debug_deactivate(timer
);
1498 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
1499 * timer could be seen as !active and just vanish away
1500 * under us on another CPU
1502 __remove_hrtimer(timer
, old_base
, HRTIMER_STATE_MIGRATE
, 0);
1503 timer
->base
= new_base
;
1505 * Enqueue the timers on the new cpu. This does not
1506 * reprogram the event device in case the timer
1507 * expires before the earliest on this CPU, but we run
1508 * hrtimer_interrupt after we migrated everything to
1509 * sort out already expired timers and reprogram the
1512 enqueue_hrtimer(timer
, new_base
);
1514 /* Clear the migration state bit */
1515 timer
->state
&= ~HRTIMER_STATE_MIGRATE
;
1519 static void migrate_hrtimers(int scpu
)
1521 struct hrtimer_cpu_base
*old_base
, *new_base
;
1524 BUG_ON(cpu_online(scpu
));
1525 tick_cancel_sched_timer(scpu
);
1527 local_irq_disable();
1528 old_base
= &per_cpu(hrtimer_bases
, scpu
);
1529 new_base
= this_cpu_ptr(&hrtimer_bases
);
1531 * The caller is globally serialized and nobody else
1532 * takes two locks at once, deadlock is not possible.
1534 raw_spin_lock(&new_base
->lock
);
1535 raw_spin_lock_nested(&old_base
->lock
, SINGLE_DEPTH_NESTING
);
1537 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++) {
1538 migrate_hrtimer_list(&old_base
->clock_base
[i
],
1539 &new_base
->clock_base
[i
]);
1542 raw_spin_unlock(&old_base
->lock
);
1543 raw_spin_unlock(&new_base
->lock
);
1545 /* Check, if we got expired work to do */
1546 __hrtimer_peek_ahead_timers();
1550 #endif /* CONFIG_HOTPLUG_CPU */
1552 static int hrtimer_cpu_notify(struct notifier_block
*self
,
1553 unsigned long action
, void *hcpu
)
1555 int scpu
= (long)hcpu
;
1559 case CPU_UP_PREPARE
:
1560 case CPU_UP_PREPARE_FROZEN
:
1561 init_hrtimers_cpu(scpu
);
1564 #ifdef CONFIG_HOTPLUG_CPU
1566 case CPU_DEAD_FROZEN
:
1567 migrate_hrtimers(scpu
);
1578 static struct notifier_block hrtimers_nb
= {
1579 .notifier_call
= hrtimer_cpu_notify
,
1582 void __init
hrtimers_init(void)
1584 hrtimer_cpu_notify(&hrtimers_nb
, (unsigned long)CPU_UP_PREPARE
,
1585 (void *)(long)smp_processor_id());
1586 register_cpu_notifier(&hrtimers_nb
);
1590 * schedule_hrtimeout_range_clock - sleep until timeout
1591 * @expires: timeout value (ktime_t)
1592 * @delta: slack in expires timeout (ktime_t)
1593 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1594 * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME
1597 schedule_hrtimeout_range_clock(ktime_t
*expires
, unsigned long delta
,
1598 const enum hrtimer_mode mode
, int clock
)
1600 struct hrtimer_sleeper t
;
1603 * Optimize when a zero timeout value is given. It does not
1604 * matter whether this is an absolute or a relative time.
1606 if (expires
&& !expires
->tv64
) {
1607 __set_current_state(TASK_RUNNING
);
1612 * A NULL parameter means "infinite"
1619 hrtimer_init_on_stack(&t
.timer
, clock
, mode
);
1620 hrtimer_set_expires_range_ns(&t
.timer
, *expires
, delta
);
1622 hrtimer_init_sleeper(&t
, current
);
1624 hrtimer_start_expires(&t
.timer
, mode
);
1629 hrtimer_cancel(&t
.timer
);
1630 destroy_hrtimer_on_stack(&t
.timer
);
1632 __set_current_state(TASK_RUNNING
);
1634 return !t
.task
? 0 : -EINTR
;
1638 * schedule_hrtimeout_range - sleep until timeout
1639 * @expires: timeout value (ktime_t)
1640 * @delta: slack in expires timeout (ktime_t)
1641 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1643 * Make the current task sleep until the given expiry time has
1644 * elapsed. The routine will return immediately unless
1645 * the current task state has been set (see set_current_state()).
1647 * The @delta argument gives the kernel the freedom to schedule the
1648 * actual wakeup to a time that is both power and performance friendly.
1649 * The kernel give the normal best effort behavior for "@expires+@delta",
1650 * but may decide to fire the timer earlier, but no earlier than @expires.
1652 * You can set the task state as follows -
1654 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1655 * pass before the routine returns.
1657 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1658 * delivered to the current task.
1660 * The current task state is guaranteed to be TASK_RUNNING when this
1663 * Returns 0 when the timer has expired otherwise -EINTR
1665 int __sched
schedule_hrtimeout_range(ktime_t
*expires
, unsigned long delta
,
1666 const enum hrtimer_mode mode
)
1668 return schedule_hrtimeout_range_clock(expires
, delta
, mode
,
1671 EXPORT_SYMBOL_GPL(schedule_hrtimeout_range
);
1674 * schedule_hrtimeout - sleep until timeout
1675 * @expires: timeout value (ktime_t)
1676 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1678 * Make the current task sleep until the given expiry time has
1679 * elapsed. The routine will return immediately unless
1680 * the current task state has been set (see set_current_state()).
1682 * You can set the task state as follows -
1684 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1685 * pass before the routine returns.
1687 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1688 * delivered to the current task.
1690 * The current task state is guaranteed to be TASK_RUNNING when this
1693 * Returns 0 when the timer has expired otherwise -EINTR
1695 int __sched
schedule_hrtimeout(ktime_t
*expires
,
1696 const enum hrtimer_mode mode
)
1698 return schedule_hrtimeout_range(expires
, 0, mode
);
1700 EXPORT_SYMBOL_GPL(schedule_hrtimeout
);