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/irq.h>
36 #include <linux/module.h>
37 #include <linux/percpu.h>
38 #include <linux/hrtimer.h>
39 #include <linux/notifier.h>
40 #include <linux/syscalls.h>
41 #include <linux/kallsyms.h>
42 #include <linux/interrupt.h>
43 #include <linux/tick.h>
44 #include <linux/seq_file.h>
45 #include <linux/err.h>
46 #include <linux/debugobjects.h>
48 #include <asm/uaccess.h>
51 * ktime_get - get the monotonic time in ktime_t format
53 * returns the time in ktime_t format
55 ktime_t
ktime_get(void)
61 return timespec_to_ktime(now
);
63 EXPORT_SYMBOL_GPL(ktime_get
);
66 * ktime_get_real - get the real (wall-) time in ktime_t format
68 * returns the time in ktime_t format
70 ktime_t
ktime_get_real(void)
76 return timespec_to_ktime(now
);
79 EXPORT_SYMBOL_GPL(ktime_get_real
);
84 * Note: If we want to add new timer bases, we have to skip the two
85 * clock ids captured by the cpu-timers. We do this by holding empty
86 * entries rather than doing math adjustment of the clock ids.
87 * This ensures that we capture erroneous accesses to these clock ids
88 * rather than moving them into the range of valid clock id's.
90 DEFINE_PER_CPU(struct hrtimer_cpu_base
, hrtimer_bases
) =
96 .index
= CLOCK_REALTIME
,
97 .get_time
= &ktime_get_real
,
98 .resolution
= KTIME_LOW_RES
,
101 .index
= CLOCK_MONOTONIC
,
102 .get_time
= &ktime_get
,
103 .resolution
= KTIME_LOW_RES
,
109 * ktime_get_ts - get the monotonic clock in timespec format
110 * @ts: pointer to timespec variable
112 * The function calculates the monotonic clock from the realtime
113 * clock and the wall_to_monotonic offset and stores the result
114 * in normalized timespec format in the variable pointed to by @ts.
116 void ktime_get_ts(struct timespec
*ts
)
118 struct timespec tomono
;
122 seq
= read_seqbegin(&xtime_lock
);
124 tomono
= wall_to_monotonic
;
126 } while (read_seqretry(&xtime_lock
, seq
));
128 set_normalized_timespec(ts
, ts
->tv_sec
+ tomono
.tv_sec
,
129 ts
->tv_nsec
+ tomono
.tv_nsec
);
131 EXPORT_SYMBOL_GPL(ktime_get_ts
);
134 * Get the coarse grained time at the softirq based on xtime and
137 static void hrtimer_get_softirq_time(struct hrtimer_cpu_base
*base
)
139 ktime_t xtim
, tomono
;
140 struct timespec xts
, tom
;
144 seq
= read_seqbegin(&xtime_lock
);
145 xts
= current_kernel_time();
146 tom
= wall_to_monotonic
;
147 } while (read_seqretry(&xtime_lock
, seq
));
149 xtim
= timespec_to_ktime(xts
);
150 tomono
= timespec_to_ktime(tom
);
151 base
->clock_base
[CLOCK_REALTIME
].softirq_time
= xtim
;
152 base
->clock_base
[CLOCK_MONOTONIC
].softirq_time
=
153 ktime_add(xtim
, tomono
);
157 * Functions and macros which are different for UP/SMP systems are kept in a
163 * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
164 * means that all timers which are tied to this base via timer->base are
165 * locked, and the base itself is locked too.
167 * So __run_timers/migrate_timers can safely modify all timers which could
168 * be found on the lists/queues.
170 * When the timer's base is locked, and the timer removed from list, it is
171 * possible to set timer->base = NULL and drop the lock: the timer remains
175 struct hrtimer_clock_base
*lock_hrtimer_base(const struct hrtimer
*timer
,
176 unsigned long *flags
)
178 struct hrtimer_clock_base
*base
;
182 if (likely(base
!= NULL
)) {
183 spin_lock_irqsave(&base
->cpu_base
->lock
, *flags
);
184 if (likely(base
== timer
->base
))
186 /* The timer has migrated to another CPU: */
187 spin_unlock_irqrestore(&base
->cpu_base
->lock
, *flags
);
194 * Switch the timer base to the current CPU when possible.
196 static inline struct hrtimer_clock_base
*
197 switch_hrtimer_base(struct hrtimer
*timer
, struct hrtimer_clock_base
*base
)
199 struct hrtimer_clock_base
*new_base
;
200 struct hrtimer_cpu_base
*new_cpu_base
;
202 new_cpu_base
= &__get_cpu_var(hrtimer_bases
);
203 new_base
= &new_cpu_base
->clock_base
[base
->index
];
205 if (base
!= new_base
) {
207 * We are trying to schedule the timer on the local CPU.
208 * However we can't change timer's base while it is running,
209 * so we keep it on the same CPU. No hassle vs. reprogramming
210 * the event source in the high resolution case. The softirq
211 * code will take care of this when the timer function has
212 * completed. There is no conflict as we hold the lock until
213 * the timer is enqueued.
215 if (unlikely(hrtimer_callback_running(timer
)))
218 /* See the comment in lock_timer_base() */
220 spin_unlock(&base
->cpu_base
->lock
);
221 spin_lock(&new_base
->cpu_base
->lock
);
222 timer
->base
= new_base
;
227 #else /* CONFIG_SMP */
229 static inline struct hrtimer_clock_base
*
230 lock_hrtimer_base(const struct hrtimer
*timer
, unsigned long *flags
)
232 struct hrtimer_clock_base
*base
= timer
->base
;
234 spin_lock_irqsave(&base
->cpu_base
->lock
, *flags
);
239 # define switch_hrtimer_base(t, b) (b)
241 #endif /* !CONFIG_SMP */
244 * Functions for the union type storage format of ktime_t which are
245 * too large for inlining:
247 #if BITS_PER_LONG < 64
248 # ifndef CONFIG_KTIME_SCALAR
250 * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
252 * @nsec: the scalar nsec value to add
254 * Returns the sum of kt and nsec in ktime_t format
256 ktime_t
ktime_add_ns(const ktime_t kt
, u64 nsec
)
260 if (likely(nsec
< NSEC_PER_SEC
)) {
263 unsigned long rem
= do_div(nsec
, NSEC_PER_SEC
);
265 tmp
= ktime_set((long)nsec
, rem
);
268 return ktime_add(kt
, tmp
);
271 EXPORT_SYMBOL_GPL(ktime_add_ns
);
274 * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable
276 * @nsec: the scalar nsec value to subtract
278 * Returns the subtraction of @nsec from @kt in ktime_t format
280 ktime_t
ktime_sub_ns(const ktime_t kt
, u64 nsec
)
284 if (likely(nsec
< NSEC_PER_SEC
)) {
287 unsigned long rem
= do_div(nsec
, NSEC_PER_SEC
);
289 tmp
= ktime_set((long)nsec
, rem
);
292 return ktime_sub(kt
, tmp
);
295 EXPORT_SYMBOL_GPL(ktime_sub_ns
);
296 # endif /* !CONFIG_KTIME_SCALAR */
299 * Divide a ktime value by a nanosecond value
301 u64
ktime_divns(const ktime_t kt
, s64 div
)
306 dclc
= ktime_to_ns(kt
);
307 /* Make sure the divisor is less than 2^32: */
313 do_div(dclc
, (unsigned long) div
);
317 #endif /* BITS_PER_LONG >= 64 */
320 * Add two ktime values and do a safety check for overflow:
322 ktime_t
ktime_add_safe(const ktime_t lhs
, const ktime_t rhs
)
324 ktime_t res
= ktime_add(lhs
, rhs
);
327 * We use KTIME_SEC_MAX here, the maximum timeout which we can
328 * return to user space in a timespec:
330 if (res
.tv64
< 0 || res
.tv64
< lhs
.tv64
|| res
.tv64
< rhs
.tv64
)
331 res
= ktime_set(KTIME_SEC_MAX
, 0);
336 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
338 static struct debug_obj_descr hrtimer_debug_descr
;
341 * fixup_init is called when:
342 * - an active object is initialized
344 static int hrtimer_fixup_init(void *addr
, enum debug_obj_state state
)
346 struct hrtimer
*timer
= addr
;
349 case ODEBUG_STATE_ACTIVE
:
350 hrtimer_cancel(timer
);
351 debug_object_init(timer
, &hrtimer_debug_descr
);
359 * fixup_activate is called when:
360 * - an active object is activated
361 * - an unknown object is activated (might be a statically initialized object)
363 static int hrtimer_fixup_activate(void *addr
, enum debug_obj_state state
)
367 case ODEBUG_STATE_NOTAVAILABLE
:
371 case ODEBUG_STATE_ACTIVE
:
380 * fixup_free is called when:
381 * - an active object is freed
383 static int hrtimer_fixup_free(void *addr
, enum debug_obj_state state
)
385 struct hrtimer
*timer
= addr
;
388 case ODEBUG_STATE_ACTIVE
:
389 hrtimer_cancel(timer
);
390 debug_object_free(timer
, &hrtimer_debug_descr
);
397 static struct debug_obj_descr hrtimer_debug_descr
= {
399 .fixup_init
= hrtimer_fixup_init
,
400 .fixup_activate
= hrtimer_fixup_activate
,
401 .fixup_free
= hrtimer_fixup_free
,
404 static inline void debug_hrtimer_init(struct hrtimer
*timer
)
406 debug_object_init(timer
, &hrtimer_debug_descr
);
409 static inline void debug_hrtimer_activate(struct hrtimer
*timer
)
411 debug_object_activate(timer
, &hrtimer_debug_descr
);
414 static inline void debug_hrtimer_deactivate(struct hrtimer
*timer
)
416 debug_object_deactivate(timer
, &hrtimer_debug_descr
);
419 static inline void debug_hrtimer_free(struct hrtimer
*timer
)
421 debug_object_free(timer
, &hrtimer_debug_descr
);
424 static void __hrtimer_init(struct hrtimer
*timer
, clockid_t clock_id
,
425 enum hrtimer_mode mode
);
427 void hrtimer_init_on_stack(struct hrtimer
*timer
, clockid_t clock_id
,
428 enum hrtimer_mode mode
)
430 debug_object_init_on_stack(timer
, &hrtimer_debug_descr
);
431 __hrtimer_init(timer
, clock_id
, mode
);
434 void destroy_hrtimer_on_stack(struct hrtimer
*timer
)
436 debug_object_free(timer
, &hrtimer_debug_descr
);
440 static inline void debug_hrtimer_init(struct hrtimer
*timer
) { }
441 static inline void debug_hrtimer_activate(struct hrtimer
*timer
) { }
442 static inline void debug_hrtimer_deactivate(struct hrtimer
*timer
) { }
446 * Check, whether the timer is on the callback pending list
448 static inline int hrtimer_cb_pending(const struct hrtimer
*timer
)
450 return timer
->state
& HRTIMER_STATE_PENDING
;
454 * Remove a timer from the callback pending list
456 static inline void hrtimer_remove_cb_pending(struct hrtimer
*timer
)
458 list_del_init(&timer
->cb_entry
);
461 /* High resolution timer related functions */
462 #ifdef CONFIG_HIGH_RES_TIMERS
465 * High resolution timer enabled ?
467 static int hrtimer_hres_enabled __read_mostly
= 1;
470 * Enable / Disable high resolution mode
472 static int __init
setup_hrtimer_hres(char *str
)
474 if (!strcmp(str
, "off"))
475 hrtimer_hres_enabled
= 0;
476 else if (!strcmp(str
, "on"))
477 hrtimer_hres_enabled
= 1;
483 __setup("highres=", setup_hrtimer_hres
);
486 * hrtimer_high_res_enabled - query, if the highres mode is enabled
488 static inline int hrtimer_is_hres_enabled(void)
490 return hrtimer_hres_enabled
;
494 * Is the high resolution mode active ?
496 static inline int hrtimer_hres_active(void)
498 return __get_cpu_var(hrtimer_bases
).hres_active
;
502 * Reprogram the event source with checking both queues for the
504 * Called with interrupts disabled and base->lock held
506 static void hrtimer_force_reprogram(struct hrtimer_cpu_base
*cpu_base
)
509 struct hrtimer_clock_base
*base
= cpu_base
->clock_base
;
512 cpu_base
->expires_next
.tv64
= KTIME_MAX
;
514 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++, base
++) {
515 struct hrtimer
*timer
;
519 timer
= rb_entry(base
->first
, struct hrtimer
, node
);
520 expires
= ktime_sub(hrtimer_get_expires(timer
), base
->offset
);
521 if (expires
.tv64
< cpu_base
->expires_next
.tv64
)
522 cpu_base
->expires_next
= expires
;
525 if (cpu_base
->expires_next
.tv64
!= KTIME_MAX
)
526 tick_program_event(cpu_base
->expires_next
, 1);
530 * Shared reprogramming for clock_realtime and clock_monotonic
532 * When a timer is enqueued and expires earlier than the already enqueued
533 * timers, we have to check, whether it expires earlier than the timer for
534 * which the clock event device was armed.
536 * Called with interrupts disabled and base->cpu_base.lock held
538 static int hrtimer_reprogram(struct hrtimer
*timer
,
539 struct hrtimer_clock_base
*base
)
541 ktime_t
*expires_next
= &__get_cpu_var(hrtimer_bases
).expires_next
;
542 ktime_t expires
= ktime_sub(hrtimer_get_expires(timer
), base
->offset
);
545 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer
) < 0);
548 * When the callback is running, we do not reprogram the clock event
549 * device. The timer callback is either running on a different CPU or
550 * the callback is executed in the hrtimer_interrupt context. The
551 * reprogramming is handled either by the softirq, which called the
552 * callback or at the end of the hrtimer_interrupt.
554 if (hrtimer_callback_running(timer
))
558 * CLOCK_REALTIME timer might be requested with an absolute
559 * expiry time which is less than base->offset. Nothing wrong
560 * about that, just avoid to call into the tick code, which
561 * has now objections against negative expiry values.
563 if (expires
.tv64
< 0)
566 if (expires
.tv64
>= expires_next
->tv64
)
570 * Clockevents returns -ETIME, when the event was in the past.
572 res
= tick_program_event(expires
, 0);
573 if (!IS_ERR_VALUE(res
))
574 *expires_next
= expires
;
580 * Retrigger next event is called after clock was set
582 * Called with interrupts disabled via on_each_cpu()
584 static void retrigger_next_event(void *arg
)
586 struct hrtimer_cpu_base
*base
;
587 struct timespec realtime_offset
;
590 if (!hrtimer_hres_active())
594 seq
= read_seqbegin(&xtime_lock
);
595 set_normalized_timespec(&realtime_offset
,
596 -wall_to_monotonic
.tv_sec
,
597 -wall_to_monotonic
.tv_nsec
);
598 } while (read_seqretry(&xtime_lock
, seq
));
600 base
= &__get_cpu_var(hrtimer_bases
);
602 /* Adjust CLOCK_REALTIME offset */
603 spin_lock(&base
->lock
);
604 base
->clock_base
[CLOCK_REALTIME
].offset
=
605 timespec_to_ktime(realtime_offset
);
607 hrtimer_force_reprogram(base
);
608 spin_unlock(&base
->lock
);
612 * Clock realtime was set
614 * Change the offset of the realtime clock vs. the monotonic
617 * We might have to reprogram the high resolution timer interrupt. On
618 * SMP we call the architecture specific code to retrigger _all_ high
619 * resolution timer interrupts. On UP we just disable interrupts and
620 * call the high resolution interrupt code.
622 void clock_was_set(void)
624 /* Retrigger the CPU local events everywhere */
625 on_each_cpu(retrigger_next_event
, NULL
, 1);
629 * During resume we might have to reprogram the high resolution timer
630 * interrupt (on the local CPU):
632 void hres_timers_resume(void)
634 /* Retrigger the CPU local events: */
635 retrigger_next_event(NULL
);
639 * Initialize the high resolution related parts of cpu_base
641 static inline void hrtimer_init_hres(struct hrtimer_cpu_base
*base
)
643 base
->expires_next
.tv64
= KTIME_MAX
;
644 base
->hres_active
= 0;
648 * Initialize the high resolution related parts of a hrtimer
650 static inline void hrtimer_init_timer_hres(struct hrtimer
*timer
)
655 * When High resolution timers are active, try to reprogram. Note, that in case
656 * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
657 * check happens. The timer gets enqueued into the rbtree. The reprogramming
658 * and expiry check is done in the hrtimer_interrupt or in the softirq.
660 static inline int hrtimer_enqueue_reprogram(struct hrtimer
*timer
,
661 struct hrtimer_clock_base
*base
)
663 if (base
->cpu_base
->hres_active
&& hrtimer_reprogram(timer
, base
)) {
665 /* Timer is expired, act upon the callback mode */
666 switch(timer
->cb_mode
) {
667 case HRTIMER_CB_IRQSAFE_NO_RESTART
:
668 debug_hrtimer_deactivate(timer
);
670 * We can call the callback from here. No restart
671 * happens, so no danger of recursion
673 BUG_ON(timer
->function(timer
) != HRTIMER_NORESTART
);
675 case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
:
677 * This is solely for the sched tick emulation with
678 * dynamic tick support to ensure that we do not
679 * restart the tick right on the edge and end up with
680 * the tick timer in the softirq ! The calling site
681 * takes care of this.
683 debug_hrtimer_deactivate(timer
);
685 case HRTIMER_CB_IRQSAFE
:
686 case HRTIMER_CB_SOFTIRQ
:
688 * Move everything else into the softirq pending list !
690 list_add_tail(&timer
->cb_entry
,
691 &base
->cpu_base
->cb_pending
);
692 timer
->state
= HRTIMER_STATE_PENDING
;
702 * Switch to high resolution mode
704 static int hrtimer_switch_to_hres(void)
706 int cpu
= smp_processor_id();
707 struct hrtimer_cpu_base
*base
= &per_cpu(hrtimer_bases
, cpu
);
710 if (base
->hres_active
)
713 local_irq_save(flags
);
715 if (tick_init_highres()) {
716 local_irq_restore(flags
);
717 printk(KERN_WARNING
"Could not switch to high resolution "
718 "mode on CPU %d\n", cpu
);
721 base
->hres_active
= 1;
722 base
->clock_base
[CLOCK_REALTIME
].resolution
= KTIME_HIGH_RES
;
723 base
->clock_base
[CLOCK_MONOTONIC
].resolution
= KTIME_HIGH_RES
;
725 tick_setup_sched_timer();
727 /* "Retrigger" the interrupt to get things going */
728 retrigger_next_event(NULL
);
729 local_irq_restore(flags
);
730 printk(KERN_DEBUG
"Switched to high resolution mode on CPU %d\n",
735 static inline void hrtimer_raise_softirq(void)
737 raise_softirq(HRTIMER_SOFTIRQ
);
742 static inline int hrtimer_hres_active(void) { return 0; }
743 static inline int hrtimer_is_hres_enabled(void) { return 0; }
744 static inline int hrtimer_switch_to_hres(void) { return 0; }
745 static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base
*base
) { }
746 static inline int hrtimer_enqueue_reprogram(struct hrtimer
*timer
,
747 struct hrtimer_clock_base
*base
)
751 static inline void hrtimer_init_hres(struct hrtimer_cpu_base
*base
) { }
752 static inline void hrtimer_init_timer_hres(struct hrtimer
*timer
) { }
753 static inline int hrtimer_reprogram(struct hrtimer
*timer
,
754 struct hrtimer_clock_base
*base
)
758 static inline void hrtimer_raise_softirq(void) { }
760 #endif /* CONFIG_HIGH_RES_TIMERS */
762 #ifdef CONFIG_TIMER_STATS
763 void __timer_stats_hrtimer_set_start_info(struct hrtimer
*timer
, void *addr
)
765 if (timer
->start_site
)
768 timer
->start_site
= addr
;
769 memcpy(timer
->start_comm
, current
->comm
, TASK_COMM_LEN
);
770 timer
->start_pid
= current
->pid
;
775 * Counterpart to lock_hrtimer_base above:
778 void unlock_hrtimer_base(const struct hrtimer
*timer
, unsigned long *flags
)
780 spin_unlock_irqrestore(&timer
->base
->cpu_base
->lock
, *flags
);
784 * hrtimer_forward - forward the timer expiry
785 * @timer: hrtimer to forward
786 * @now: forward past this time
787 * @interval: the interval to forward
789 * Forward the timer expiry so it will expire in the future.
790 * Returns the number of overruns.
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
< timer
->base
->resolution
.tv64
)
803 interval
.tv64
= timer
->base
->resolution
.tv64
;
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 static void enqueue_hrtimer(struct hrtimer
*timer
,
831 struct hrtimer_clock_base
*base
, int reprogram
)
833 struct rb_node
**link
= &base
->active
.rb_node
;
834 struct rb_node
*parent
= NULL
;
835 struct hrtimer
*entry
;
838 debug_hrtimer_activate(timer
);
841 * Find the right place in the rbtree:
845 entry
= rb_entry(parent
, struct hrtimer
, node
);
847 * We dont care about collisions. Nodes with
848 * the same expiry time stay together.
850 if (hrtimer_get_expires_tv64(timer
) <
851 hrtimer_get_expires_tv64(entry
)) {
852 link
= &(*link
)->rb_left
;
854 link
= &(*link
)->rb_right
;
860 * Insert the timer to the rbtree and check whether it
861 * replaces the first pending timer
865 * Reprogram the clock event device. When the timer is already
866 * expired hrtimer_enqueue_reprogram has either called the
867 * callback or added it to the pending list and raised the
870 * This is a NOP for !HIGHRES
872 if (reprogram
&& hrtimer_enqueue_reprogram(timer
, base
))
875 base
->first
= &timer
->node
;
878 rb_link_node(&timer
->node
, parent
, link
);
879 rb_insert_color(&timer
->node
, &base
->active
);
881 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
882 * state of a possibly running callback.
884 timer
->state
|= HRTIMER_STATE_ENQUEUED
;
888 * __remove_hrtimer - internal function to remove a timer
890 * Caller must hold the base lock.
892 * High resolution timer mode reprograms the clock event device when the
893 * timer is the one which expires next. The caller can disable this by setting
894 * reprogram to zero. This is useful, when the context does a reprogramming
895 * anyway (e.g. timer interrupt)
897 static void __remove_hrtimer(struct hrtimer
*timer
,
898 struct hrtimer_clock_base
*base
,
899 unsigned long newstate
, int reprogram
)
901 /* High res. callback list. NOP for !HIGHRES */
902 if (hrtimer_cb_pending(timer
))
903 hrtimer_remove_cb_pending(timer
);
906 * Remove the timer from the rbtree and replace the
907 * first entry pointer if necessary.
909 if (base
->first
== &timer
->node
) {
910 base
->first
= rb_next(&timer
->node
);
911 /* Reprogram the clock event device. if enabled */
912 if (reprogram
&& hrtimer_hres_active())
913 hrtimer_force_reprogram(base
->cpu_base
);
915 rb_erase(&timer
->node
, &base
->active
);
917 timer
->state
= newstate
;
921 * remove hrtimer, called with base lock held
924 remove_hrtimer(struct hrtimer
*timer
, struct hrtimer_clock_base
*base
)
926 if (hrtimer_is_queued(timer
)) {
930 * Remove the timer and force reprogramming when high
931 * resolution mode is active and the timer is on the current
932 * CPU. If we remove a timer on another CPU, reprogramming is
933 * skipped. The interrupt event on this CPU is fired and
934 * reprogramming happens in the interrupt handler. This is a
935 * rare case and less expensive than a smp call.
937 debug_hrtimer_deactivate(timer
);
938 timer_stats_hrtimer_clear_start_info(timer
);
939 reprogram
= base
->cpu_base
== &__get_cpu_var(hrtimer_bases
);
940 __remove_hrtimer(timer
, base
, HRTIMER_STATE_INACTIVE
,
948 * hrtimer_start_range_ns - (re)start an relative timer on the current CPU
949 * @timer: the timer to be added
951 * @delta_ns: "slack" range for the timer
952 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
956 * 1 when the timer was active
959 hrtimer_start_range_ns(struct hrtimer
*timer
, ktime_t tim
, unsigned long delta_ns
,
960 const enum hrtimer_mode mode
)
962 struct hrtimer_clock_base
*base
, *new_base
;
966 base
= lock_hrtimer_base(timer
, &flags
);
968 /* Remove an active timer from the queue: */
969 ret
= remove_hrtimer(timer
, base
);
971 /* Switch the timer base, if necessary: */
972 new_base
= switch_hrtimer_base(timer
, base
);
974 if (mode
== HRTIMER_MODE_REL
) {
975 tim
= ktime_add_safe(tim
, new_base
->get_time());
977 * CONFIG_TIME_LOW_RES is a temporary way for architectures
978 * to signal that they simply return xtime in
979 * do_gettimeoffset(). In this case we want to round up by
980 * resolution when starting a relative timer, to avoid short
981 * timeouts. This will go away with the GTOD framework.
983 #ifdef CONFIG_TIME_LOW_RES
984 tim
= ktime_add_safe(tim
, base
->resolution
);
988 hrtimer_set_expires_range_ns(timer
, tim
, delta_ns
);
990 timer_stats_hrtimer_set_start_info(timer
);
993 * Only allow reprogramming if the new base is on this CPU.
994 * (it might still be on another CPU if the timer was pending)
996 enqueue_hrtimer(timer
, new_base
,
997 new_base
->cpu_base
== &__get_cpu_var(hrtimer_bases
));
1000 * The timer may be expired and moved to the cb_pending
1001 * list. We can not raise the softirq with base lock held due
1002 * to a possible deadlock with runqueue lock.
1004 raise
= timer
->state
== HRTIMER_STATE_PENDING
;
1007 * We use preempt_disable to prevent this task from migrating after
1008 * setting up the softirq and raising it. Otherwise, if me migrate
1009 * we will raise the softirq on the wrong CPU.
1013 unlock_hrtimer_base(timer
, &flags
);
1016 hrtimer_raise_softirq();
1021 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns
);
1024 * hrtimer_start - (re)start an relative timer on the current CPU
1025 * @timer: the timer to be added
1027 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
1031 * 1 when the timer was active
1034 hrtimer_start(struct hrtimer
*timer
, ktime_t tim
, const enum hrtimer_mode mode
)
1036 return hrtimer_start_range_ns(timer
, tim
, 0, mode
);
1038 EXPORT_SYMBOL_GPL(hrtimer_start
);
1042 * hrtimer_try_to_cancel - try to deactivate a timer
1043 * @timer: hrtimer to stop
1046 * 0 when the timer was not active
1047 * 1 when the timer was active
1048 * -1 when the timer is currently excuting the callback function and
1051 int hrtimer_try_to_cancel(struct hrtimer
*timer
)
1053 struct hrtimer_clock_base
*base
;
1054 unsigned long flags
;
1057 base
= lock_hrtimer_base(timer
, &flags
);
1059 if (!hrtimer_callback_running(timer
))
1060 ret
= remove_hrtimer(timer
, base
);
1062 unlock_hrtimer_base(timer
, &flags
);
1067 EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel
);
1070 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
1071 * @timer: the timer to be cancelled
1074 * 0 when the timer was not active
1075 * 1 when the timer was active
1077 int hrtimer_cancel(struct hrtimer
*timer
)
1080 int ret
= hrtimer_try_to_cancel(timer
);
1087 EXPORT_SYMBOL_GPL(hrtimer_cancel
);
1090 * hrtimer_get_remaining - get remaining time for the timer
1091 * @timer: the timer to read
1093 ktime_t
hrtimer_get_remaining(const struct hrtimer
*timer
)
1095 struct hrtimer_clock_base
*base
;
1096 unsigned long flags
;
1099 base
= lock_hrtimer_base(timer
, &flags
);
1100 rem
= hrtimer_expires_remaining(timer
);
1101 unlock_hrtimer_base(timer
, &flags
);
1105 EXPORT_SYMBOL_GPL(hrtimer_get_remaining
);
1109 * hrtimer_get_next_event - get the time until next expiry event
1111 * Returns the delta to the next expiry event or KTIME_MAX if no timer
1114 ktime_t
hrtimer_get_next_event(void)
1116 struct hrtimer_cpu_base
*cpu_base
= &__get_cpu_var(hrtimer_bases
);
1117 struct hrtimer_clock_base
*base
= cpu_base
->clock_base
;
1118 ktime_t delta
, mindelta
= { .tv64
= KTIME_MAX
};
1119 unsigned long flags
;
1122 spin_lock_irqsave(&cpu_base
->lock
, flags
);
1124 if (!hrtimer_hres_active()) {
1125 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++, base
++) {
1126 struct hrtimer
*timer
;
1131 timer
= rb_entry(base
->first
, struct hrtimer
, node
);
1132 delta
.tv64
= hrtimer_get_expires_tv64(timer
);
1133 delta
= ktime_sub(delta
, base
->get_time());
1134 if (delta
.tv64
< mindelta
.tv64
)
1135 mindelta
.tv64
= delta
.tv64
;
1139 spin_unlock_irqrestore(&cpu_base
->lock
, flags
);
1141 if (mindelta
.tv64
< 0)
1147 static void __hrtimer_init(struct hrtimer
*timer
, clockid_t clock_id
,
1148 enum hrtimer_mode mode
)
1150 struct hrtimer_cpu_base
*cpu_base
;
1152 memset(timer
, 0, sizeof(struct hrtimer
));
1154 cpu_base
= &__raw_get_cpu_var(hrtimer_bases
);
1156 if (clock_id
== CLOCK_REALTIME
&& mode
!= HRTIMER_MODE_ABS
)
1157 clock_id
= CLOCK_MONOTONIC
;
1159 timer
->base
= &cpu_base
->clock_base
[clock_id
];
1160 INIT_LIST_HEAD(&timer
->cb_entry
);
1161 hrtimer_init_timer_hres(timer
);
1163 #ifdef CONFIG_TIMER_STATS
1164 timer
->start_site
= NULL
;
1165 timer
->start_pid
= -1;
1166 memset(timer
->start_comm
, 0, TASK_COMM_LEN
);
1171 * hrtimer_init - initialize a timer to the given clock
1172 * @timer: the timer to be initialized
1173 * @clock_id: the clock to be used
1174 * @mode: timer mode abs/rel
1176 void hrtimer_init(struct hrtimer
*timer
, clockid_t clock_id
,
1177 enum hrtimer_mode mode
)
1179 debug_hrtimer_init(timer
);
1180 __hrtimer_init(timer
, clock_id
, mode
);
1182 EXPORT_SYMBOL_GPL(hrtimer_init
);
1185 * hrtimer_get_res - get the timer resolution for a clock
1186 * @which_clock: which clock to query
1187 * @tp: pointer to timespec variable to store the resolution
1189 * Store the resolution of the clock selected by @which_clock in the
1190 * variable pointed to by @tp.
1192 int hrtimer_get_res(const clockid_t which_clock
, struct timespec
*tp
)
1194 struct hrtimer_cpu_base
*cpu_base
;
1196 cpu_base
= &__raw_get_cpu_var(hrtimer_bases
);
1197 *tp
= ktime_to_timespec(cpu_base
->clock_base
[which_clock
].resolution
);
1201 EXPORT_SYMBOL_GPL(hrtimer_get_res
);
1203 static void run_hrtimer_pending(struct hrtimer_cpu_base
*cpu_base
)
1205 spin_lock_irq(&cpu_base
->lock
);
1207 while (!list_empty(&cpu_base
->cb_pending
)) {
1208 enum hrtimer_restart (*fn
)(struct hrtimer
*);
1209 struct hrtimer
*timer
;
1212 timer
= list_entry(cpu_base
->cb_pending
.next
,
1213 struct hrtimer
, cb_entry
);
1215 debug_hrtimer_deactivate(timer
);
1216 timer_stats_account_hrtimer(timer
);
1218 fn
= timer
->function
;
1219 __remove_hrtimer(timer
, timer
->base
, HRTIMER_STATE_CALLBACK
, 0);
1220 spin_unlock_irq(&cpu_base
->lock
);
1222 restart
= fn(timer
);
1224 spin_lock_irq(&cpu_base
->lock
);
1226 timer
->state
&= ~HRTIMER_STATE_CALLBACK
;
1227 if (restart
== HRTIMER_RESTART
) {
1228 BUG_ON(hrtimer_active(timer
));
1230 * Enqueue the timer, allow reprogramming of the event
1233 enqueue_hrtimer(timer
, timer
->base
, 1);
1234 } else if (hrtimer_active(timer
)) {
1236 * If the timer was rearmed on another CPU, reprogram
1239 struct hrtimer_clock_base
*base
= timer
->base
;
1241 if (base
->first
== &timer
->node
&&
1242 hrtimer_reprogram(timer
, base
)) {
1244 * Timer is expired. Thus move it from tree to
1245 * pending list again.
1247 __remove_hrtimer(timer
, base
,
1248 HRTIMER_STATE_PENDING
, 0);
1249 list_add_tail(&timer
->cb_entry
,
1250 &base
->cpu_base
->cb_pending
);
1254 spin_unlock_irq(&cpu_base
->lock
);
1257 static void __run_hrtimer(struct hrtimer
*timer
)
1259 struct hrtimer_clock_base
*base
= timer
->base
;
1260 struct hrtimer_cpu_base
*cpu_base
= base
->cpu_base
;
1261 enum hrtimer_restart (*fn
)(struct hrtimer
*);
1264 debug_hrtimer_deactivate(timer
);
1265 __remove_hrtimer(timer
, base
, HRTIMER_STATE_CALLBACK
, 0);
1266 timer_stats_account_hrtimer(timer
);
1268 fn
= timer
->function
;
1269 if (timer
->cb_mode
== HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
) {
1271 * Used for scheduler timers, avoid lock inversion with
1272 * rq->lock and tasklist_lock.
1274 * These timers are required to deal with enqueue expiry
1275 * themselves and are not allowed to migrate.
1277 spin_unlock(&cpu_base
->lock
);
1278 restart
= fn(timer
);
1279 spin_lock(&cpu_base
->lock
);
1281 restart
= fn(timer
);
1284 * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid
1285 * reprogramming of the event hardware. This happens at the end of this
1288 if (restart
!= HRTIMER_NORESTART
) {
1289 BUG_ON(timer
->state
!= HRTIMER_STATE_CALLBACK
);
1290 enqueue_hrtimer(timer
, base
, 0);
1292 timer
->state
&= ~HRTIMER_STATE_CALLBACK
;
1295 #ifdef CONFIG_HIGH_RES_TIMERS
1298 * High resolution timer interrupt
1299 * Called with interrupts disabled
1301 void hrtimer_interrupt(struct clock_event_device
*dev
)
1303 struct hrtimer_cpu_base
*cpu_base
= &__get_cpu_var(hrtimer_bases
);
1304 struct hrtimer_clock_base
*base
;
1305 ktime_t expires_next
, now
;
1308 BUG_ON(!cpu_base
->hres_active
);
1309 cpu_base
->nr_events
++;
1310 dev
->next_event
.tv64
= KTIME_MAX
;
1315 expires_next
.tv64
= KTIME_MAX
;
1317 base
= cpu_base
->clock_base
;
1319 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++) {
1321 struct rb_node
*node
;
1323 spin_lock(&cpu_base
->lock
);
1325 basenow
= ktime_add(now
, base
->offset
);
1327 while ((node
= base
->first
)) {
1328 struct hrtimer
*timer
;
1330 timer
= rb_entry(node
, struct hrtimer
, node
);
1333 * The immediate goal for using the softexpires is
1334 * minimizing wakeups, not running timers at the
1335 * earliest interrupt after their soft expiration.
1336 * This allows us to avoid using a Priority Search
1337 * Tree, which can answer a stabbing querry for
1338 * overlapping intervals and instead use the simple
1339 * BST we already have.
1340 * We don't add extra wakeups by delaying timers that
1341 * are right-of a not yet expired timer, because that
1342 * timer will have to trigger a wakeup anyway.
1345 if (basenow
.tv64
< hrtimer_get_softexpires_tv64(timer
)) {
1348 expires
= ktime_sub(hrtimer_get_expires(timer
),
1350 if (expires
.tv64
< expires_next
.tv64
)
1351 expires_next
= expires
;
1355 /* Move softirq callbacks to the pending list */
1356 if (timer
->cb_mode
== HRTIMER_CB_SOFTIRQ
) {
1357 __remove_hrtimer(timer
, base
,
1358 HRTIMER_STATE_PENDING
, 0);
1359 list_add_tail(&timer
->cb_entry
,
1360 &base
->cpu_base
->cb_pending
);
1365 __run_hrtimer(timer
);
1367 spin_unlock(&cpu_base
->lock
);
1371 cpu_base
->expires_next
= expires_next
;
1373 /* Reprogramming necessary ? */
1374 if (expires_next
.tv64
!= KTIME_MAX
) {
1375 if (tick_program_event(expires_next
, 0))
1379 /* Raise softirq ? */
1381 raise_softirq(HRTIMER_SOFTIRQ
);
1385 * hrtimer_peek_ahead_timers -- run soft-expired timers now
1387 * hrtimer_peek_ahead_timers will peek at the timer queue of
1388 * the current cpu and check if there are any timers for which
1389 * the soft expires time has passed. If any such timers exist,
1390 * they are run immediately and then removed from the timer queue.
1393 void hrtimer_peek_ahead_timers(void)
1395 unsigned long flags
;
1396 struct tick_device
*td
;
1397 struct clock_event_device
*dev
;
1399 if (!hrtimer_hres_active())
1402 local_irq_save(flags
);
1403 td
= &__get_cpu_var(tick_cpu_device
);
1409 hrtimer_interrupt(dev
);
1411 local_irq_restore(flags
);
1414 static void run_hrtimer_softirq(struct softirq_action
*h
)
1416 run_hrtimer_pending(&__get_cpu_var(hrtimer_bases
));
1419 #endif /* CONFIG_HIGH_RES_TIMERS */
1422 * Called from timer softirq every jiffy, expire hrtimers:
1424 * For HRT its the fall back code to run the softirq in the timer
1425 * softirq context in case the hrtimer initialization failed or has
1426 * not been done yet.
1428 void hrtimer_run_pending(void)
1430 struct hrtimer_cpu_base
*cpu_base
= &__get_cpu_var(hrtimer_bases
);
1432 if (hrtimer_hres_active())
1436 * This _is_ ugly: We have to check in the softirq context,
1437 * whether we can switch to highres and / or nohz mode. The
1438 * clocksource switch happens in the timer interrupt with
1439 * xtime_lock held. Notification from there only sets the
1440 * check bit in the tick_oneshot code, otherwise we might
1441 * deadlock vs. xtime_lock.
1443 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1444 hrtimer_switch_to_hres();
1446 run_hrtimer_pending(cpu_base
);
1450 * Called from hardirq context every jiffy
1452 void hrtimer_run_queues(void)
1454 struct rb_node
*node
;
1455 struct hrtimer_cpu_base
*cpu_base
= &__get_cpu_var(hrtimer_bases
);
1456 struct hrtimer_clock_base
*base
;
1457 int index
, gettime
= 1;
1459 if (hrtimer_hres_active())
1462 for (index
= 0; index
< HRTIMER_MAX_CLOCK_BASES
; index
++) {
1463 base
= &cpu_base
->clock_base
[index
];
1468 if (base
->get_softirq_time
)
1469 base
->softirq_time
= base
->get_softirq_time();
1471 hrtimer_get_softirq_time(cpu_base
);
1475 spin_lock(&cpu_base
->lock
);
1477 while ((node
= base
->first
)) {
1478 struct hrtimer
*timer
;
1480 timer
= rb_entry(node
, struct hrtimer
, node
);
1481 if (base
->softirq_time
.tv64
<=
1482 hrtimer_get_expires_tv64(timer
))
1485 if (timer
->cb_mode
== HRTIMER_CB_SOFTIRQ
) {
1486 __remove_hrtimer(timer
, base
,
1487 HRTIMER_STATE_PENDING
, 0);
1488 list_add_tail(&timer
->cb_entry
,
1489 &base
->cpu_base
->cb_pending
);
1493 __run_hrtimer(timer
);
1495 spin_unlock(&cpu_base
->lock
);
1500 * Sleep related functions:
1502 static enum hrtimer_restart
hrtimer_wakeup(struct hrtimer
*timer
)
1504 struct hrtimer_sleeper
*t
=
1505 container_of(timer
, struct hrtimer_sleeper
, timer
);
1506 struct task_struct
*task
= t
->task
;
1510 wake_up_process(task
);
1512 return HRTIMER_NORESTART
;
1515 void hrtimer_init_sleeper(struct hrtimer_sleeper
*sl
, struct task_struct
*task
)
1517 sl
->timer
.function
= hrtimer_wakeup
;
1519 #ifdef CONFIG_HIGH_RES_TIMERS
1520 sl
->timer
.cb_mode
= HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
;
1524 static int __sched
do_nanosleep(struct hrtimer_sleeper
*t
, enum hrtimer_mode mode
)
1526 hrtimer_init_sleeper(t
, current
);
1529 set_current_state(TASK_INTERRUPTIBLE
);
1530 hrtimer_start_expires(&t
->timer
, mode
);
1531 if (!hrtimer_active(&t
->timer
))
1534 if (likely(t
->task
))
1537 hrtimer_cancel(&t
->timer
);
1538 mode
= HRTIMER_MODE_ABS
;
1540 } while (t
->task
&& !signal_pending(current
));
1542 __set_current_state(TASK_RUNNING
);
1544 return t
->task
== NULL
;
1547 static int update_rmtp(struct hrtimer
*timer
, struct timespec __user
*rmtp
)
1549 struct timespec rmt
;
1552 rem
= hrtimer_expires_remaining(timer
);
1555 rmt
= ktime_to_timespec(rem
);
1557 if (copy_to_user(rmtp
, &rmt
, sizeof(*rmtp
)))
1563 long __sched
hrtimer_nanosleep_restart(struct restart_block
*restart
)
1565 struct hrtimer_sleeper t
;
1566 struct timespec __user
*rmtp
;
1569 hrtimer_init_on_stack(&t
.timer
, restart
->nanosleep
.index
,
1571 hrtimer_set_expires_tv64(&t
.timer
, restart
->nanosleep
.expires
);
1573 if (do_nanosleep(&t
, HRTIMER_MODE_ABS
))
1576 rmtp
= restart
->nanosleep
.rmtp
;
1578 ret
= update_rmtp(&t
.timer
, rmtp
);
1583 /* The other values in restart are already filled in */
1584 ret
= -ERESTART_RESTARTBLOCK
;
1586 destroy_hrtimer_on_stack(&t
.timer
);
1590 long hrtimer_nanosleep(struct timespec
*rqtp
, struct timespec __user
*rmtp
,
1591 const enum hrtimer_mode mode
, const clockid_t clockid
)
1593 struct restart_block
*restart
;
1594 struct hrtimer_sleeper t
;
1596 unsigned long slack
;
1598 slack
= current
->timer_slack_ns
;
1599 if (rt_task(current
))
1602 hrtimer_init_on_stack(&t
.timer
, clockid
, mode
);
1603 hrtimer_set_expires_range_ns(&t
.timer
, timespec_to_ktime(*rqtp
), slack
);
1604 if (do_nanosleep(&t
, mode
))
1607 /* Absolute timers do not update the rmtp value and restart: */
1608 if (mode
== HRTIMER_MODE_ABS
) {
1609 ret
= -ERESTARTNOHAND
;
1614 ret
= update_rmtp(&t
.timer
, rmtp
);
1619 restart
= ¤t_thread_info()->restart_block
;
1620 restart
->fn
= hrtimer_nanosleep_restart
;
1621 restart
->nanosleep
.index
= t
.timer
.base
->index
;
1622 restart
->nanosleep
.rmtp
= rmtp
;
1623 restart
->nanosleep
.expires
= hrtimer_get_expires_tv64(&t
.timer
);
1625 ret
= -ERESTART_RESTARTBLOCK
;
1627 destroy_hrtimer_on_stack(&t
.timer
);
1632 sys_nanosleep(struct timespec __user
*rqtp
, struct timespec __user
*rmtp
)
1636 if (copy_from_user(&tu
, rqtp
, sizeof(tu
)))
1639 if (!timespec_valid(&tu
))
1642 return hrtimer_nanosleep(&tu
, rmtp
, HRTIMER_MODE_REL
, CLOCK_MONOTONIC
);
1646 * Functions related to boot-time initialization:
1648 static void __cpuinit
init_hrtimers_cpu(int cpu
)
1650 struct hrtimer_cpu_base
*cpu_base
= &per_cpu(hrtimer_bases
, cpu
);
1653 spin_lock_init(&cpu_base
->lock
);
1655 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++)
1656 cpu_base
->clock_base
[i
].cpu_base
= cpu_base
;
1658 INIT_LIST_HEAD(&cpu_base
->cb_pending
);
1659 hrtimer_init_hres(cpu_base
);
1662 #ifdef CONFIG_HOTPLUG_CPU
1664 static void migrate_hrtimer_list(struct hrtimer_clock_base
*old_base
,
1665 struct hrtimer_clock_base
*new_base
)
1667 struct hrtimer
*timer
;
1668 struct rb_node
*node
;
1670 while ((node
= rb_first(&old_base
->active
))) {
1671 timer
= rb_entry(node
, struct hrtimer
, node
);
1672 BUG_ON(hrtimer_callback_running(timer
));
1673 debug_hrtimer_deactivate(timer
);
1674 __remove_hrtimer(timer
, old_base
, HRTIMER_STATE_INACTIVE
, 0);
1675 timer
->base
= new_base
;
1677 * Enqueue the timer. Allow reprogramming of the event device
1679 enqueue_hrtimer(timer
, new_base
, 1);
1683 static void migrate_hrtimers(int cpu
)
1685 struct hrtimer_cpu_base
*old_base
, *new_base
;
1688 BUG_ON(cpu_online(cpu
));
1689 old_base
= &per_cpu(hrtimer_bases
, cpu
);
1690 new_base
= &get_cpu_var(hrtimer_bases
);
1692 tick_cancel_sched_timer(cpu
);
1694 local_irq_disable();
1695 spin_lock(&new_base
->lock
);
1696 spin_lock_nested(&old_base
->lock
, SINGLE_DEPTH_NESTING
);
1698 for (i
= 0; i
< HRTIMER_MAX_CLOCK_BASES
; i
++) {
1699 migrate_hrtimer_list(&old_base
->clock_base
[i
],
1700 &new_base
->clock_base
[i
]);
1703 spin_unlock(&old_base
->lock
);
1704 spin_unlock(&new_base
->lock
);
1706 put_cpu_var(hrtimer_bases
);
1708 #endif /* CONFIG_HOTPLUG_CPU */
1710 static int __cpuinit
hrtimer_cpu_notify(struct notifier_block
*self
,
1711 unsigned long action
, void *hcpu
)
1713 unsigned int cpu
= (long)hcpu
;
1717 case CPU_UP_PREPARE
:
1718 case CPU_UP_PREPARE_FROZEN
:
1719 init_hrtimers_cpu(cpu
);
1722 #ifdef CONFIG_HOTPLUG_CPU
1724 case CPU_DEAD_FROZEN
:
1725 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD
, &cpu
);
1726 migrate_hrtimers(cpu
);
1737 static struct notifier_block __cpuinitdata hrtimers_nb
= {
1738 .notifier_call
= hrtimer_cpu_notify
,
1741 void __init
hrtimers_init(void)
1743 hrtimer_cpu_notify(&hrtimers_nb
, (unsigned long)CPU_UP_PREPARE
,
1744 (void *)(long)smp_processor_id());
1745 register_cpu_notifier(&hrtimers_nb
);
1746 #ifdef CONFIG_HIGH_RES_TIMERS
1747 open_softirq(HRTIMER_SOFTIRQ
, run_hrtimer_softirq
);
1752 * schedule_hrtimeout_range - sleep until timeout
1753 * @expires: timeout value (ktime_t)
1754 * @delta: slack in expires timeout (ktime_t)
1755 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1757 * Make the current task sleep until the given expiry time has
1758 * elapsed. The routine will return immediately unless
1759 * the current task state has been set (see set_current_state()).
1761 * The @delta argument gives the kernel the freedom to schedule the
1762 * actual wakeup to a time that is both power and performance friendly.
1763 * The kernel give the normal best effort behavior for "@expires+@delta",
1764 * but may decide to fire the timer earlier, but no earlier than @expires.
1766 * You can set the task state as follows -
1768 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1769 * pass before the routine returns.
1771 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1772 * delivered to the current task.
1774 * The current task state is guaranteed to be TASK_RUNNING when this
1777 * Returns 0 when the timer has expired otherwise -EINTR
1779 int __sched
schedule_hrtimeout_range(ktime_t
*expires
, unsigned long delta
,
1780 const enum hrtimer_mode mode
)
1782 struct hrtimer_sleeper t
;
1785 * Optimize when a zero timeout value is given. It does not
1786 * matter whether this is an absolute or a relative time.
1788 if (expires
&& !expires
->tv64
) {
1789 __set_current_state(TASK_RUNNING
);
1794 * A NULL parameter means "inifinte"
1798 __set_current_state(TASK_RUNNING
);
1802 hrtimer_init_on_stack(&t
.timer
, CLOCK_MONOTONIC
, mode
);
1803 hrtimer_set_expires_range_ns(&t
.timer
, *expires
, delta
);
1805 hrtimer_init_sleeper(&t
, current
);
1807 hrtimer_start_expires(&t
.timer
, mode
);
1808 if (!hrtimer_active(&t
.timer
))
1814 hrtimer_cancel(&t
.timer
);
1815 destroy_hrtimer_on_stack(&t
.timer
);
1817 __set_current_state(TASK_RUNNING
);
1819 return !t
.task
? 0 : -EINTR
;
1821 EXPORT_SYMBOL_GPL(schedule_hrtimeout_range
);
1824 * schedule_hrtimeout - sleep until timeout
1825 * @expires: timeout value (ktime_t)
1826 * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
1828 * Make the current task sleep until the given expiry time has
1829 * elapsed. The routine will return immediately unless
1830 * the current task state has been set (see set_current_state()).
1832 * You can set the task state as follows -
1834 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
1835 * pass before the routine returns.
1837 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1838 * delivered to the current task.
1840 * The current task state is guaranteed to be TASK_RUNNING when this
1843 * Returns 0 when the timer has expired otherwise -EINTR
1845 int __sched
schedule_hrtimeout(ktime_t
*expires
,
1846 const enum hrtimer_mode mode
)
1848 return schedule_hrtimeout_range(expires
, 0, mode
);
1850 EXPORT_SYMBOL_GPL(schedule_hrtimeout
);