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
== addr
&& timer
->start_pid
== current
->pid
)
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
);