4 * Kernel internal timers, basic process system calls
6 * Copyright (C) 1991, 1992 Linus Torvalds
8 * 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better.
10 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
11 * "A Kernel Model for Precision Timekeeping" by Dave Mills
12 * 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
13 * serialize accesses to xtime/lost_ticks).
14 * Copyright (C) 1998 Andrea Arcangeli
15 * 1999-03-10 Improved NTP compatibility by Ulrich Windl
16 * 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love
17 * 2000-10-05 Implemented scalable SMP per-CPU timer handling.
18 * Copyright (C) 2000, 2001, 2002 Ingo Molnar
19 * Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar
22 #include <linux/kernel_stat.h>
23 #include <linux/module.h>
24 #include <linux/interrupt.h>
25 #include <linux/percpu.h>
26 #include <linux/init.h>
28 #include <linux/swap.h>
29 #include <linux/pid_namespace.h>
30 #include <linux/notifier.h>
31 #include <linux/thread_info.h>
32 #include <linux/time.h>
33 #include <linux/jiffies.h>
34 #include <linux/posix-timers.h>
35 #include <linux/cpu.h>
36 #include <linux/syscalls.h>
37 #include <linux/delay.h>
38 #include <linux/tick.h>
39 #include <linux/kallsyms.h>
40 #include <linux/perf_event.h>
41 #include <linux/sched.h>
42 #include <linux/slab.h>
44 #include <asm/uaccess.h>
45 #include <asm/unistd.h>
46 #include <asm/div64.h>
47 #include <asm/timex.h>
50 #define CREATE_TRACE_POINTS
51 #include <trace/events/timer.h>
53 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
55 EXPORT_SYMBOL(jiffies_64);
58 * per-CPU timer vector definitions:
60 #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
61 #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
62 #define TVN_SIZE (1 << TVN_BITS)
63 #define TVR_SIZE (1 << TVR_BITS)
64 #define TVN_MASK (TVN_SIZE - 1)
65 #define TVR_MASK (TVR_SIZE - 1)
68 struct list_head vec[TVN_SIZE];
72 struct list_head vec[TVR_SIZE];
77 struct timer_list *running_timer;
78 unsigned long timer_jiffies;
79 unsigned long next_timer;
85 } ____cacheline_aligned;
87 struct tvec_base boot_tvec_bases;
88 EXPORT_SYMBOL(boot_tvec_bases);
89 static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
91 /* Functions below help us manage 'deferrable' flag */
92 static inline unsigned int tbase_get_deferrable(struct tvec_base *base)
94 return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG);
97 static inline struct tvec_base *tbase_get_base(struct tvec_base *base)
99 return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG));
102 static inline void timer_set_deferrable(struct timer_list *timer)
104 timer->base = TBASE_MAKE_DEFERRED(timer->base);
108 timer_set_base(struct timer_list *timer, struct tvec_base *new_base)
110 timer->base = (struct tvec_base *)((unsigned long)(new_base) |
111 tbase_get_deferrable(timer->base));
114 static unsigned long round_jiffies_common(unsigned long j, int cpu,
118 unsigned long original = j;
121 * We don't want all cpus firing their timers at once hitting the
122 * same lock or cachelines, so we skew each extra cpu with an extra
123 * 3 jiffies. This 3 jiffies came originally from the mm/ code which
125 * The skew is done by adding 3*cpunr, then round, then subtract this
126 * extra offset again.
133 * If the target jiffie is just after a whole second (which can happen
134 * due to delays of the timer irq, long irq off times etc etc) then
135 * we should round down to the whole second, not up. Use 1/4th second
136 * as cutoff for this rounding as an extreme upper bound for this.
137 * But never round down if @force_up is set.
139 if (rem < HZ/4 && !force_up) /* round down */
144 /* now that we have rounded, subtract the extra skew again */
147 if (j <= jiffies) /* rounding ate our timeout entirely; */
153 * __round_jiffies - function to round jiffies to a full second
154 * @j: the time in (absolute) jiffies that should be rounded
155 * @cpu: the processor number on which the timeout will happen
157 * __round_jiffies() rounds an absolute time in the future (in jiffies)
158 * up or down to (approximately) full seconds. This is useful for timers
159 * for which the exact time they fire does not matter too much, as long as
160 * they fire approximately every X seconds.
162 * By rounding these timers to whole seconds, all such timers will fire
163 * at the same time, rather than at various times spread out. The goal
164 * of this is to have the CPU wake up less, which saves power.
166 * The exact rounding is skewed for each processor to avoid all
167 * processors firing at the exact same time, which could lead
168 * to lock contention or spurious cache line bouncing.
170 * The return value is the rounded version of the @j parameter.
172 unsigned long __round_jiffies(unsigned long j, int cpu)
174 return round_jiffies_common(j, cpu, false);
176 EXPORT_SYMBOL_GPL(__round_jiffies);
179 * __round_jiffies_relative - function to round jiffies to a full second
180 * @j: the time in (relative) jiffies that should be rounded
181 * @cpu: the processor number on which the timeout will happen
183 * __round_jiffies_relative() rounds a time delta in the future (in jiffies)
184 * up or down to (approximately) full seconds. This is useful for timers
185 * for which the exact time they fire does not matter too much, as long as
186 * they fire approximately every X seconds.
188 * By rounding these timers to whole seconds, all such timers will fire
189 * at the same time, rather than at various times spread out. The goal
190 * of this is to have the CPU wake up less, which saves power.
192 * The exact rounding is skewed for each processor to avoid all
193 * processors firing at the exact same time, which could lead
194 * to lock contention or spurious cache line bouncing.
196 * The return value is the rounded version of the @j parameter.
198 unsigned long __round_jiffies_relative(unsigned long j, int cpu)
200 unsigned long j0 = jiffies;
202 /* Use j0 because jiffies might change while we run */
203 return round_jiffies_common(j + j0, cpu, false) - j0;
205 EXPORT_SYMBOL_GPL(__round_jiffies_relative);
208 * round_jiffies - function to round jiffies to a full second
209 * @j: the time in (absolute) jiffies that should be rounded
211 * round_jiffies() rounds an absolute time in the future (in jiffies)
212 * up or down to (approximately) full seconds. This is useful for timers
213 * for which the exact time they fire does not matter too much, as long as
214 * they fire approximately every X seconds.
216 * By rounding these timers to whole seconds, all such timers will fire
217 * at the same time, rather than at various times spread out. The goal
218 * of this is to have the CPU wake up less, which saves power.
220 * The return value is the rounded version of the @j parameter.
222 unsigned long round_jiffies(unsigned long j)
224 return round_jiffies_common(j, raw_smp_processor_id(), false);
226 EXPORT_SYMBOL_GPL(round_jiffies);
229 * round_jiffies_relative - function to round jiffies to a full second
230 * @j: the time in (relative) jiffies that should be rounded
232 * round_jiffies_relative() rounds a time delta in the future (in jiffies)
233 * up or down to (approximately) full seconds. This is useful for timers
234 * for which the exact time they fire does not matter too much, as long as
235 * they fire approximately every X seconds.
237 * By rounding these timers to whole seconds, all such timers will fire
238 * at the same time, rather than at various times spread out. The goal
239 * of this is to have the CPU wake up less, which saves power.
241 * The return value is the rounded version of the @j parameter.
243 unsigned long round_jiffies_relative(unsigned long j)
245 return __round_jiffies_relative(j, raw_smp_processor_id());
247 EXPORT_SYMBOL_GPL(round_jiffies_relative);
250 * __round_jiffies_up - function to round jiffies up to a full second
251 * @j: the time in (absolute) jiffies that should be rounded
252 * @cpu: the processor number on which the timeout will happen
254 * This is the same as __round_jiffies() except that it will never
255 * round down. This is useful for timeouts for which the exact time
256 * of firing does not matter too much, as long as they don't fire too
259 unsigned long __round_jiffies_up(unsigned long j, int cpu)
261 return round_jiffies_common(j, cpu, true);
263 EXPORT_SYMBOL_GPL(__round_jiffies_up);
266 * __round_jiffies_up_relative - function to round jiffies up to a full second
267 * @j: the time in (relative) jiffies that should be rounded
268 * @cpu: the processor number on which the timeout will happen
270 * This is the same as __round_jiffies_relative() except that it will never
271 * round down. This is useful for timeouts for which the exact time
272 * of firing does not matter too much, as long as they don't fire too
275 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu)
277 unsigned long j0 = jiffies;
279 /* Use j0 because jiffies might change while we run */
280 return round_jiffies_common(j + j0, cpu, true) - j0;
282 EXPORT_SYMBOL_GPL(__round_jiffies_up_relative);
285 * round_jiffies_up - function to round jiffies up to a full second
286 * @j: the time in (absolute) jiffies that should be rounded
288 * This is the same as round_jiffies() except that it will never
289 * round down. This is useful for timeouts for which the exact time
290 * of firing does not matter too much, as long as they don't fire too
293 unsigned long round_jiffies_up(unsigned long j)
295 return round_jiffies_common(j, raw_smp_processor_id(), true);
297 EXPORT_SYMBOL_GPL(round_jiffies_up);
300 * round_jiffies_up_relative - function to round jiffies up to a full second
301 * @j: the time in (relative) jiffies that should be rounded
303 * This is the same as round_jiffies_relative() except that it will never
304 * round down. This is useful for timeouts for which the exact time
305 * of firing does not matter too much, as long as they don't fire too
308 unsigned long round_jiffies_up_relative(unsigned long j)
310 return __round_jiffies_up_relative(j, raw_smp_processor_id());
312 EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
315 * set_timer_slack - set the allowed slack for a timer
316 * @timer: the timer to be modified
317 * @slack_hz: the amount of time (in jiffies) allowed for rounding
319 * Set the amount of time, in jiffies, that a certain timer has
320 * in terms of slack. By setting this value, the timer subsystem
321 * will schedule the actual timer somewhere between
322 * the time mod_timer() asks for, and that time plus the slack.
324 * By setting the slack to -1, a percentage of the delay is used
327 void set_timer_slack(struct timer_list *timer, int slack_hz)
329 timer->slack = slack_hz;
331 EXPORT_SYMBOL_GPL(set_timer_slack);
334 static inline void set_running_timer(struct tvec_base *base,
335 struct timer_list *timer)
338 base->running_timer = timer;
342 static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
344 unsigned long expires = timer->expires;
345 unsigned long idx = expires - base->timer_jiffies;
346 struct list_head *vec;
348 if (idx < TVR_SIZE) {
349 int i = expires & TVR_MASK;
350 vec = base->tv1.vec + i;
351 } else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
352 int i = (expires >> TVR_BITS) & TVN_MASK;
353 vec = base->tv2.vec + i;
354 } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
355 int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
356 vec = base->tv3.vec + i;
357 } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
358 int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
359 vec = base->tv4.vec + i;
360 } else if ((signed long) idx < 0) {
362 * Can happen if you add a timer with expires == jiffies,
363 * or you set a timer to go off in the past
365 vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK);
368 /* If the timeout is larger than 0xffffffff on 64-bit
369 * architectures then we use the maximum timeout:
371 if (idx > 0xffffffffUL) {
373 expires = idx + base->timer_jiffies;
375 i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
376 vec = base->tv5.vec + i;
381 list_add_tail(&timer->entry, vec);
384 #ifdef CONFIG_TIMER_STATS
385 void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
387 if (timer->start_site)
390 timer->start_site = addr;
391 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
392 timer->start_pid = current->pid;
395 static void timer_stats_account_timer(struct timer_list *timer)
397 unsigned int flag = 0;
399 if (likely(!timer->start_site))
401 if (unlikely(tbase_get_deferrable(timer->base)))
402 flag |= TIMER_STATS_FLAG_DEFERRABLE;
404 timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
405 timer->function, timer->start_comm, flag);
409 static void timer_stats_account_timer(struct timer_list *timer) {}
412 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
414 static struct debug_obj_descr timer_debug_descr;
417 * fixup_init is called when:
418 * - an active object is initialized
420 static int timer_fixup_init(void *addr, enum debug_obj_state state)
422 struct timer_list *timer = addr;
425 case ODEBUG_STATE_ACTIVE:
426 del_timer_sync(timer);
427 debug_object_init(timer, &timer_debug_descr);
435 * fixup_activate is called when:
436 * - an active object is activated
437 * - an unknown object is activated (might be a statically initialized object)
439 static int timer_fixup_activate(void *addr, enum debug_obj_state state)
441 struct timer_list *timer = addr;
445 case ODEBUG_STATE_NOTAVAILABLE:
447 * This is not really a fixup. The timer was
448 * statically initialized. We just make sure that it
449 * is tracked in the object tracker.
451 if (timer->entry.next == NULL &&
452 timer->entry.prev == TIMER_ENTRY_STATIC) {
453 debug_object_init(timer, &timer_debug_descr);
454 debug_object_activate(timer, &timer_debug_descr);
461 case ODEBUG_STATE_ACTIVE:
470 * fixup_free is called when:
471 * - an active object is freed
473 static int timer_fixup_free(void *addr, enum debug_obj_state state)
475 struct timer_list *timer = addr;
478 case ODEBUG_STATE_ACTIVE:
479 del_timer_sync(timer);
480 debug_object_free(timer, &timer_debug_descr);
487 static struct debug_obj_descr timer_debug_descr = {
488 .name = "timer_list",
489 .fixup_init = timer_fixup_init,
490 .fixup_activate = timer_fixup_activate,
491 .fixup_free = timer_fixup_free,
494 static inline void debug_timer_init(struct timer_list *timer)
496 debug_object_init(timer, &timer_debug_descr);
499 static inline void debug_timer_activate(struct timer_list *timer)
501 debug_object_activate(timer, &timer_debug_descr);
504 static inline void debug_timer_deactivate(struct timer_list *timer)
506 debug_object_deactivate(timer, &timer_debug_descr);
509 static inline void debug_timer_free(struct timer_list *timer)
511 debug_object_free(timer, &timer_debug_descr);
514 static void __init_timer(struct timer_list *timer,
516 struct lock_class_key *key);
518 void init_timer_on_stack_key(struct timer_list *timer,
520 struct lock_class_key *key)
522 debug_object_init_on_stack(timer, &timer_debug_descr);
523 __init_timer(timer, name, key);
525 EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
527 void destroy_timer_on_stack(struct timer_list *timer)
529 debug_object_free(timer, &timer_debug_descr);
531 EXPORT_SYMBOL_GPL(destroy_timer_on_stack);
534 static inline void debug_timer_init(struct timer_list *timer) { }
535 static inline void debug_timer_activate(struct timer_list *timer) { }
536 static inline void debug_timer_deactivate(struct timer_list *timer) { }
539 static inline void debug_init(struct timer_list *timer)
541 debug_timer_init(timer);
542 trace_timer_init(timer);
546 debug_activate(struct timer_list *timer, unsigned long expires)
548 debug_timer_activate(timer);
549 trace_timer_start(timer, expires);
552 static inline void debug_deactivate(struct timer_list *timer)
554 debug_timer_deactivate(timer);
555 trace_timer_cancel(timer);
558 static void __init_timer(struct timer_list *timer,
560 struct lock_class_key *key)
562 timer->entry.next = NULL;
563 timer->base = __raw_get_cpu_var(tvec_bases);
565 #ifdef CONFIG_TIMER_STATS
566 timer->start_site = NULL;
567 timer->start_pid = -1;
568 memset(timer->start_comm, 0, TASK_COMM_LEN);
570 lockdep_init_map(&timer->lockdep_map, name, key, 0);
573 void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
575 struct lock_class_key *key,
576 void (*function)(unsigned long),
579 timer->function = function;
581 init_timer_on_stack_key(timer, name, key);
582 timer_set_deferrable(timer);
584 EXPORT_SYMBOL_GPL(setup_deferrable_timer_on_stack_key);
587 * init_timer_key - initialize a timer
588 * @timer: the timer to be initialized
589 * @name: name of the timer
590 * @key: lockdep class key of the fake lock used for tracking timer
591 * sync lock dependencies
593 * init_timer_key() must be done to a timer prior calling *any* of the
594 * other timer functions.
596 void init_timer_key(struct timer_list *timer,
598 struct lock_class_key *key)
601 __init_timer(timer, name, key);
603 EXPORT_SYMBOL(init_timer_key);
605 void init_timer_deferrable_key(struct timer_list *timer,
607 struct lock_class_key *key)
609 init_timer_key(timer, name, key);
610 timer_set_deferrable(timer);
612 EXPORT_SYMBOL(init_timer_deferrable_key);
614 static inline void detach_timer(struct timer_list *timer,
617 struct list_head *entry = &timer->entry;
619 debug_deactivate(timer);
621 __list_del(entry->prev, entry->next);
624 entry->prev = LIST_POISON2;
628 * We are using hashed locking: holding per_cpu(tvec_bases).lock
629 * means that all timers which are tied to this base via timer->base are
630 * locked, and the base itself is locked too.
632 * So __run_timers/migrate_timers can safely modify all timers which could
633 * be found on ->tvX lists.
635 * When the timer's base is locked, and the timer removed from list, it is
636 * possible to set timer->base = NULL and drop the lock: the timer remains
639 static struct tvec_base *lock_timer_base(struct timer_list *timer,
640 unsigned long *flags)
641 __acquires(timer->base->lock)
643 struct tvec_base *base;
646 struct tvec_base *prelock_base = timer->base;
647 base = tbase_get_base(prelock_base);
648 if (likely(base != NULL)) {
649 spin_lock_irqsave(&base->lock, *flags);
650 if (likely(prelock_base == timer->base))
652 /* The timer has migrated to another CPU */
653 spin_unlock_irqrestore(&base->lock, *flags);
660 __mod_timer(struct timer_list *timer, unsigned long expires,
661 bool pending_only, int pinned)
663 struct tvec_base *base, *new_base;
667 timer_stats_timer_set_start_info(timer);
668 BUG_ON(!timer->function);
670 base = lock_timer_base(timer, &flags);
672 if (timer_pending(timer)) {
673 detach_timer(timer, 0);
674 if (timer->expires == base->next_timer &&
675 !tbase_get_deferrable(timer->base))
676 base->next_timer = base->timer_jiffies;
683 debug_activate(timer, expires);
685 cpu = smp_processor_id();
687 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
688 if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu))
689 cpu = get_nohz_timer_target();
691 new_base = per_cpu(tvec_bases, cpu);
693 if (base != new_base) {
695 * We are trying to schedule the timer on the local CPU.
696 * However we can't change timer's base while it is running,
697 * otherwise del_timer_sync() can't detect that the timer's
698 * handler yet has not finished. This also guarantees that
699 * the timer is serialized wrt itself.
701 if (likely(base->running_timer != timer)) {
702 /* See the comment in lock_timer_base() */
703 timer_set_base(timer, NULL);
704 spin_unlock(&base->lock);
706 spin_lock(&base->lock);
707 timer_set_base(timer, base);
711 timer->expires = expires;
712 if (time_before(timer->expires, base->next_timer) &&
713 !tbase_get_deferrable(timer->base))
714 base->next_timer = timer->expires;
715 internal_add_timer(base, timer);
718 spin_unlock_irqrestore(&base->lock, flags);
724 * mod_timer_pending - modify a pending timer's timeout
725 * @timer: the pending timer to be modified
726 * @expires: new timeout in jiffies
728 * mod_timer_pending() is the same for pending timers as mod_timer(),
729 * but will not re-activate and modify already deleted timers.
731 * It is useful for unserialized use of timers.
733 int mod_timer_pending(struct timer_list *timer, unsigned long expires)
735 return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
737 EXPORT_SYMBOL(mod_timer_pending);
740 * Decide where to put the timer while taking the slack into account
743 * 1) calculate the maximum (absolute) time
744 * 2) calculate the highest bit where the expires and new max are different
745 * 3) use this bit to make a mask
746 * 4) use the bitmask to round down the maximum time, so that all last
750 unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
752 unsigned long expires_limit, mask;
755 expires_limit = expires;
757 if (timer->slack >= 0) {
758 expires_limit = expires + timer->slack;
760 unsigned long now = jiffies;
762 /* No slack, if already expired else auto slack 0.4% */
763 if (time_after(expires, now))
764 expires_limit = expires + (expires - now)/256;
766 mask = expires ^ expires_limit;
770 bit = find_last_bit(&mask, BITS_PER_LONG);
772 mask = (1 << bit) - 1;
774 expires_limit = expires_limit & ~(mask);
776 return expires_limit;
780 * mod_timer - modify a timer's timeout
781 * @timer: the timer to be modified
782 * @expires: new timeout in jiffies
784 * mod_timer() is a more efficient way to update the expire field of an
785 * active timer (if the timer is inactive it will be activated)
787 * mod_timer(timer, expires) is equivalent to:
789 * del_timer(timer); timer->expires = expires; add_timer(timer);
791 * Note that if there are multiple unserialized concurrent users of the
792 * same timer, then mod_timer() is the only safe way to modify the timeout,
793 * since add_timer() cannot modify an already running timer.
795 * The function returns whether it has modified a pending timer or not.
796 * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
797 * active timer returns 1.)
799 int mod_timer(struct timer_list *timer, unsigned long expires)
802 * This is a common optimization triggered by the
803 * networking code - if the timer is re-modified
804 * to be the same thing then just return:
806 if (timer_pending(timer) && timer->expires == expires)
809 expires = apply_slack(timer, expires);
811 return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
813 EXPORT_SYMBOL(mod_timer);
816 * mod_timer_pinned - modify a timer's timeout
817 * @timer: the timer to be modified
818 * @expires: new timeout in jiffies
820 * mod_timer_pinned() is a way to update the expire field of an
821 * active timer (if the timer is inactive it will be activated)
822 * and not allow the timer to be migrated to a different CPU.
824 * mod_timer_pinned(timer, expires) is equivalent to:
826 * del_timer(timer); timer->expires = expires; add_timer(timer);
828 int mod_timer_pinned(struct timer_list *timer, unsigned long expires)
830 if (timer->expires == expires && timer_pending(timer))
833 return __mod_timer(timer, expires, false, TIMER_PINNED);
835 EXPORT_SYMBOL(mod_timer_pinned);
838 * add_timer - start a timer
839 * @timer: the timer to be added
841 * The kernel will do a ->function(->data) callback from the
842 * timer interrupt at the ->expires point in the future. The
843 * current time is 'jiffies'.
845 * The timer's ->expires, ->function (and if the handler uses it, ->data)
846 * fields must be set prior calling this function.
848 * Timers with an ->expires field in the past will be executed in the next
851 void add_timer(struct timer_list *timer)
853 BUG_ON(timer_pending(timer));
854 mod_timer(timer, timer->expires);
856 EXPORT_SYMBOL(add_timer);
859 * add_timer_on - start a timer on a particular CPU
860 * @timer: the timer to be added
861 * @cpu: the CPU to start it on
863 * This is not very scalable on SMP. Double adds are not possible.
865 void add_timer_on(struct timer_list *timer, int cpu)
867 struct tvec_base *base = per_cpu(tvec_bases, cpu);
870 timer_stats_timer_set_start_info(timer);
871 BUG_ON(timer_pending(timer) || !timer->function);
872 spin_lock_irqsave(&base->lock, flags);
873 timer_set_base(timer, base);
874 debug_activate(timer, timer->expires);
875 if (time_before(timer->expires, base->next_timer) &&
876 !tbase_get_deferrable(timer->base))
877 base->next_timer = timer->expires;
878 internal_add_timer(base, timer);
880 * Check whether the other CPU is idle and needs to be
881 * triggered to reevaluate the timer wheel when nohz is
882 * active. We are protected against the other CPU fiddling
883 * with the timer by holding the timer base lock. This also
884 * makes sure that a CPU on the way to idle can not evaluate
887 wake_up_idle_cpu(cpu);
888 spin_unlock_irqrestore(&base->lock, flags);
890 EXPORT_SYMBOL_GPL(add_timer_on);
893 * del_timer - deactive a timer.
894 * @timer: the timer to be deactivated
896 * del_timer() deactivates a timer - this works on both active and inactive
899 * The function returns whether it has deactivated a pending timer or not.
900 * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
901 * active timer returns 1.)
903 int del_timer(struct timer_list *timer)
905 struct tvec_base *base;
909 timer_stats_timer_clear_start_info(timer);
910 if (timer_pending(timer)) {
911 base = lock_timer_base(timer, &flags);
912 if (timer_pending(timer)) {
913 detach_timer(timer, 1);
914 if (timer->expires == base->next_timer &&
915 !tbase_get_deferrable(timer->base))
916 base->next_timer = base->timer_jiffies;
919 spin_unlock_irqrestore(&base->lock, flags);
924 EXPORT_SYMBOL(del_timer);
928 * try_to_del_timer_sync - Try to deactivate a timer
929 * @timer: timer do del
931 * This function tries to deactivate a timer. Upon successful (ret >= 0)
932 * exit the timer is not queued and the handler is not running on any CPU.
934 * It must not be called from interrupt contexts.
936 int try_to_del_timer_sync(struct timer_list *timer)
938 struct tvec_base *base;
942 base = lock_timer_base(timer, &flags);
944 if (base->running_timer == timer)
947 timer_stats_timer_clear_start_info(timer);
949 if (timer_pending(timer)) {
950 detach_timer(timer, 1);
951 if (timer->expires == base->next_timer &&
952 !tbase_get_deferrable(timer->base))
953 base->next_timer = base->timer_jiffies;
957 spin_unlock_irqrestore(&base->lock, flags);
961 EXPORT_SYMBOL(try_to_del_timer_sync);
964 * del_timer_sync - deactivate a timer and wait for the handler to finish.
965 * @timer: the timer to be deactivated
967 * This function only differs from del_timer() on SMP: besides deactivating
968 * the timer it also makes sure the handler has finished executing on other
971 * Synchronization rules: Callers must prevent restarting of the timer,
972 * otherwise this function is meaningless. It must not be called from
973 * interrupt contexts. The caller must not hold locks which would prevent
974 * completion of the timer's handler. The timer's handler must not call
975 * add_timer_on(). Upon exit the timer is not queued and the handler is
976 * not running on any CPU.
978 * The function returns whether it has deactivated a pending timer or not.
980 int del_timer_sync(struct timer_list *timer)
982 #ifdef CONFIG_LOCKDEP
985 local_irq_save(flags);
986 lock_map_acquire(&timer->lockdep_map);
987 lock_map_release(&timer->lockdep_map);
988 local_irq_restore(flags);
992 int ret = try_to_del_timer_sync(timer);
998 EXPORT_SYMBOL(del_timer_sync);
1001 static int cascade(struct tvec_base *base, struct tvec *tv, int index)
1003 /* cascade all the timers from tv up one level */
1004 struct timer_list *timer, *tmp;
1005 struct list_head tv_list;
1007 list_replace_init(tv->vec + index, &tv_list);
1010 * We are removing _all_ timers from the list, so we
1011 * don't have to detach them individually.
1013 list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
1014 BUG_ON(tbase_get_base(timer->base) != base);
1015 internal_add_timer(base, timer);
1021 static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
1024 int preempt_count = preempt_count();
1026 #ifdef CONFIG_LOCKDEP
1028 * It is permissible to free the timer from inside the
1029 * function that is called from it, this we need to take into
1030 * account for lockdep too. To avoid bogus "held lock freed"
1031 * warnings as well as problems when looking into
1032 * timer->lockdep_map, make a copy and use that here.
1034 struct lockdep_map lockdep_map = timer->lockdep_map;
1037 * Couple the lock chain with the lock chain at
1038 * del_timer_sync() by acquiring the lock_map around the fn()
1039 * call here and in del_timer_sync().
1041 lock_map_acquire(&lockdep_map);
1043 trace_timer_expire_entry(timer);
1045 trace_timer_expire_exit(timer);
1047 lock_map_release(&lockdep_map);
1049 if (preempt_count != preempt_count()) {
1050 WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n",
1051 fn, preempt_count, preempt_count());
1053 * Restore the preempt count. That gives us a decent
1054 * chance to survive and extract information. If the
1055 * callback kept a lock held, bad luck, but not worse
1056 * than the BUG() we had.
1058 preempt_count() = preempt_count;
1062 #define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
1065 * __run_timers - run all expired timers (if any) on this CPU.
1066 * @base: the timer vector to be processed.
1068 * This function cascades all vectors and executes all expired timer
1071 static inline void __run_timers(struct tvec_base *base)
1073 struct timer_list *timer;
1075 spin_lock_irq(&base->lock);
1076 while (time_after_eq(jiffies, base->timer_jiffies)) {
1077 struct list_head work_list;
1078 struct list_head *head = &work_list;
1079 int index = base->timer_jiffies & TVR_MASK;
1085 (!cascade(base, &base->tv2, INDEX(0))) &&
1086 (!cascade(base, &base->tv3, INDEX(1))) &&
1087 !cascade(base, &base->tv4, INDEX(2)))
1088 cascade(base, &base->tv5, INDEX(3));
1089 ++base->timer_jiffies;
1090 list_replace_init(base->tv1.vec + index, &work_list);
1091 while (!list_empty(head)) {
1092 void (*fn)(unsigned long);
1095 timer = list_first_entry(head, struct timer_list,entry);
1096 fn = timer->function;
1099 timer_stats_account_timer(timer);
1101 set_running_timer(base, timer);
1102 detach_timer(timer, 1);
1104 spin_unlock_irq(&base->lock);
1105 call_timer_fn(timer, fn, data);
1106 spin_lock_irq(&base->lock);
1109 set_running_timer(base, NULL);
1110 spin_unlock_irq(&base->lock);
1115 * Find out when the next timer event is due to happen. This
1116 * is used on S/390 to stop all activity when a CPU is idle.
1117 * This function needs to be called with interrupts disabled.
1119 static unsigned long __next_timer_interrupt(struct tvec_base *base)
1121 unsigned long timer_jiffies = base->timer_jiffies;
1122 unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA;
1123 int index, slot, array, found = 0;
1124 struct timer_list *nte;
1125 struct tvec *varray[4];
1127 /* Look for timer events in tv1. */
1128 index = slot = timer_jiffies & TVR_MASK;
1130 list_for_each_entry(nte, base->tv1.vec + slot, entry) {
1131 if (tbase_get_deferrable(nte->base))
1135 expires = nte->expires;
1136 /* Look at the cascade bucket(s)? */
1137 if (!index || slot < index)
1141 slot = (slot + 1) & TVR_MASK;
1142 } while (slot != index);
1145 /* Calculate the next cascade event */
1147 timer_jiffies += TVR_SIZE - index;
1148 timer_jiffies >>= TVR_BITS;
1150 /* Check tv2-tv5. */
1151 varray[0] = &base->tv2;
1152 varray[1] = &base->tv3;
1153 varray[2] = &base->tv4;
1154 varray[3] = &base->tv5;
1156 for (array = 0; array < 4; array++) {
1157 struct tvec *varp = varray[array];
1159 index = slot = timer_jiffies & TVN_MASK;
1161 list_for_each_entry(nte, varp->vec + slot, entry) {
1162 if (tbase_get_deferrable(nte->base))
1166 if (time_before(nte->expires, expires))
1167 expires = nte->expires;
1170 * Do we still search for the first timer or are
1171 * we looking up the cascade buckets ?
1174 /* Look at the cascade bucket(s)? */
1175 if (!index || slot < index)
1179 slot = (slot + 1) & TVN_MASK;
1180 } while (slot != index);
1183 timer_jiffies += TVN_SIZE - index;
1184 timer_jiffies >>= TVN_BITS;
1190 * Check, if the next hrtimer event is before the next timer wheel
1193 static unsigned long cmp_next_hrtimer_event(unsigned long now,
1194 unsigned long expires)
1196 ktime_t hr_delta = hrtimer_get_next_event();
1197 struct timespec tsdelta;
1198 unsigned long delta;
1200 if (hr_delta.tv64 == KTIME_MAX)
1204 * Expired timer available, let it expire in the next tick
1206 if (hr_delta.tv64 <= 0)
1209 tsdelta = ktime_to_timespec(hr_delta);
1210 delta = timespec_to_jiffies(&tsdelta);
1213 * Limit the delta to the max value, which is checked in
1214 * tick_nohz_stop_sched_tick():
1216 if (delta > NEXT_TIMER_MAX_DELTA)
1217 delta = NEXT_TIMER_MAX_DELTA;
1220 * Take rounding errors in to account and make sure, that it
1221 * expires in the next tick. Otherwise we go into an endless
1222 * ping pong due to tick_nohz_stop_sched_tick() retriggering
1228 if (time_before(now, expires))
1234 * get_next_timer_interrupt - return the jiffy of the next pending timer
1235 * @now: current time (in jiffies)
1237 unsigned long get_next_timer_interrupt(unsigned long now)
1239 struct tvec_base *base = __get_cpu_var(tvec_bases);
1240 unsigned long expires;
1242 spin_lock(&base->lock);
1243 if (time_before_eq(base->next_timer, base->timer_jiffies))
1244 base->next_timer = __next_timer_interrupt(base);
1245 expires = base->next_timer;
1246 spin_unlock(&base->lock);
1248 if (time_before_eq(expires, now))
1251 return cmp_next_hrtimer_event(now, expires);
1256 * Called from the timer interrupt handler to charge one tick to the current
1257 * process. user_tick is 1 if the tick is user time, 0 for system.
1259 void update_process_times(int user_tick)
1261 struct task_struct *p = current;
1262 int cpu = smp_processor_id();
1264 /* Note: this timer irq context must be accounted for as well. */
1265 account_process_tick(p, user_tick);
1267 rcu_check_callbacks(cpu, user_tick);
1269 perf_event_do_pending();
1271 run_posix_cpu_timers(p);
1275 * This function runs timers and the timer-tq in bottom half context.
1277 static void run_timer_softirq(struct softirq_action *h)
1279 struct tvec_base *base = __get_cpu_var(tvec_bases);
1281 hrtimer_run_pending();
1283 if (time_after_eq(jiffies, base->timer_jiffies))
1288 * Called by the local, per-CPU timer interrupt on SMP.
1290 void run_local_timers(void)
1292 hrtimer_run_queues();
1293 raise_softirq(TIMER_SOFTIRQ);
1297 * The 64-bit jiffies value is not atomic - you MUST NOT read it
1298 * without sampling the sequence number in xtime_lock.
1299 * jiffies is defined in the linker script...
1302 void do_timer(unsigned long ticks)
1304 jiffies_64 += ticks;
1309 #ifdef __ARCH_WANT_SYS_ALARM
1312 * For backwards compatibility? This can be done in libc so Alpha
1313 * and all newer ports shouldn't need it.
1315 SYSCALL_DEFINE1(alarm, unsigned int, seconds)
1317 return alarm_setitimer(seconds);
1325 * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this
1326 * should be moved into arch/i386 instead?
1330 * sys_getpid - return the thread group id of the current process
1332 * Note, despite the name, this returns the tgid not the pid. The tgid and
1333 * the pid are identical unless CLONE_THREAD was specified on clone() in
1334 * which case the tgid is the same in all threads of the same group.
1336 * This is SMP safe as current->tgid does not change.
1338 SYSCALL_DEFINE0(getpid)
1340 return task_tgid_vnr(current);
1344 * Accessing ->real_parent is not SMP-safe, it could
1345 * change from under us. However, we can use a stale
1346 * value of ->real_parent under rcu_read_lock(), see
1347 * release_task()->call_rcu(delayed_put_task_struct).
1349 SYSCALL_DEFINE0(getppid)
1354 pid = task_tgid_vnr(current->real_parent);
1360 SYSCALL_DEFINE0(getuid)
1362 /* Only we change this so SMP safe */
1363 return current_uid();
1366 SYSCALL_DEFINE0(geteuid)
1368 /* Only we change this so SMP safe */
1369 return current_euid();
1372 SYSCALL_DEFINE0(getgid)
1374 /* Only we change this so SMP safe */
1375 return current_gid();
1378 SYSCALL_DEFINE0(getegid)
1380 /* Only we change this so SMP safe */
1381 return current_egid();
1386 static void process_timeout(unsigned long __data)
1388 wake_up_process((struct task_struct *)__data);
1392 * schedule_timeout - sleep until timeout
1393 * @timeout: timeout value in jiffies
1395 * Make the current task sleep until @timeout jiffies have
1396 * elapsed. The routine will return immediately unless
1397 * the current task state has been set (see set_current_state()).
1399 * You can set the task state as follows -
1401 * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
1402 * pass before the routine returns. The routine will return 0
1404 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1405 * delivered to the current task. In this case the remaining time
1406 * in jiffies will be returned, or 0 if the timer expired in time
1408 * The current task state is guaranteed to be TASK_RUNNING when this
1411 * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
1412 * the CPU away without a bound on the timeout. In this case the return
1413 * value will be %MAX_SCHEDULE_TIMEOUT.
1415 * In all cases the return value is guaranteed to be non-negative.
1417 signed long __sched schedule_timeout(signed long timeout)
1419 struct timer_list timer;
1420 unsigned long expire;
1424 case MAX_SCHEDULE_TIMEOUT:
1426 * These two special cases are useful to be comfortable
1427 * in the caller. Nothing more. We could take
1428 * MAX_SCHEDULE_TIMEOUT from one of the negative value
1429 * but I' d like to return a valid offset (>=0) to allow
1430 * the caller to do everything it want with the retval.
1436 * Another bit of PARANOID. Note that the retval will be
1437 * 0 since no piece of kernel is supposed to do a check
1438 * for a negative retval of schedule_timeout() (since it
1439 * should never happens anyway). You just have the printk()
1440 * that will tell you if something is gone wrong and where.
1443 printk(KERN_ERR "schedule_timeout: wrong timeout "
1444 "value %lx\n", timeout);
1446 current->state = TASK_RUNNING;
1451 expire = timeout + jiffies;
1453 setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
1454 __mod_timer(&timer, expire, false, TIMER_NOT_PINNED);
1456 del_singleshot_timer_sync(&timer);
1458 /* Remove the timer from the object tracker */
1459 destroy_timer_on_stack(&timer);
1461 timeout = expire - jiffies;
1464 return timeout < 0 ? 0 : timeout;
1466 EXPORT_SYMBOL(schedule_timeout);
1469 * We can use __set_current_state() here because schedule_timeout() calls
1470 * schedule() unconditionally.
1472 signed long __sched schedule_timeout_interruptible(signed long timeout)
1474 __set_current_state(TASK_INTERRUPTIBLE);
1475 return schedule_timeout(timeout);
1477 EXPORT_SYMBOL(schedule_timeout_interruptible);
1479 signed long __sched schedule_timeout_killable(signed long timeout)
1481 __set_current_state(TASK_KILLABLE);
1482 return schedule_timeout(timeout);
1484 EXPORT_SYMBOL(schedule_timeout_killable);
1486 signed long __sched schedule_timeout_uninterruptible(signed long timeout)
1488 __set_current_state(TASK_UNINTERRUPTIBLE);
1489 return schedule_timeout(timeout);
1491 EXPORT_SYMBOL(schedule_timeout_uninterruptible);
1493 /* Thread ID - the internal kernel "pid" */
1494 SYSCALL_DEFINE0(gettid)
1496 return task_pid_vnr(current);
1500 * do_sysinfo - fill in sysinfo struct
1501 * @info: pointer to buffer to fill
1503 int do_sysinfo(struct sysinfo *info)
1505 unsigned long mem_total, sav_total;
1506 unsigned int mem_unit, bitcount;
1509 memset(info, 0, sizeof(struct sysinfo));
1512 monotonic_to_bootbased(&tp);
1513 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
1515 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
1517 info->procs = nr_threads;
1523 * If the sum of all the available memory (i.e. ram + swap)
1524 * is less than can be stored in a 32 bit unsigned long then
1525 * we can be binary compatible with 2.2.x kernels. If not,
1526 * well, in that case 2.2.x was broken anyways...
1528 * -Erik Andersen <andersee@debian.org>
1531 mem_total = info->totalram + info->totalswap;
1532 if (mem_total < info->totalram || mem_total < info->totalswap)
1535 mem_unit = info->mem_unit;
1536 while (mem_unit > 1) {
1539 sav_total = mem_total;
1541 if (mem_total < sav_total)
1546 * If mem_total did not overflow, multiply all memory values by
1547 * info->mem_unit and set it to 1. This leaves things compatible
1548 * with 2.2.x, and also retains compatibility with earlier 2.4.x
1553 info->totalram <<= bitcount;
1554 info->freeram <<= bitcount;
1555 info->sharedram <<= bitcount;
1556 info->bufferram <<= bitcount;
1557 info->totalswap <<= bitcount;
1558 info->freeswap <<= bitcount;
1559 info->totalhigh <<= bitcount;
1560 info->freehigh <<= bitcount;
1566 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
1572 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
1578 static int __cpuinit init_timers_cpu(int cpu)
1581 struct tvec_base *base;
1582 static char __cpuinitdata tvec_base_done[NR_CPUS];
1584 if (!tvec_base_done[cpu]) {
1585 static char boot_done;
1589 * The APs use this path later in boot
1591 base = kmalloc_node(sizeof(*base),
1592 GFP_KERNEL | __GFP_ZERO,
1597 /* Make sure that tvec_base is 2 byte aligned */
1598 if (tbase_get_deferrable(base)) {
1603 per_cpu(tvec_bases, cpu) = base;
1606 * This is for the boot CPU - we use compile-time
1607 * static initialisation because per-cpu memory isn't
1608 * ready yet and because the memory allocators are not
1609 * initialised either.
1612 base = &boot_tvec_bases;
1614 tvec_base_done[cpu] = 1;
1616 base = per_cpu(tvec_bases, cpu);
1619 spin_lock_init(&base->lock);
1621 for (j = 0; j < TVN_SIZE; j++) {
1622 INIT_LIST_HEAD(base->tv5.vec + j);
1623 INIT_LIST_HEAD(base->tv4.vec + j);
1624 INIT_LIST_HEAD(base->tv3.vec + j);
1625 INIT_LIST_HEAD(base->tv2.vec + j);
1627 for (j = 0; j < TVR_SIZE; j++)
1628 INIT_LIST_HEAD(base->tv1.vec + j);
1630 base->timer_jiffies = jiffies;
1631 base->next_timer = base->timer_jiffies;
1635 #ifdef CONFIG_HOTPLUG_CPU
1636 static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head)
1638 struct timer_list *timer;
1640 while (!list_empty(head)) {
1641 timer = list_first_entry(head, struct timer_list, entry);
1642 detach_timer(timer, 0);
1643 timer_set_base(timer, new_base);
1644 if (time_before(timer->expires, new_base->next_timer) &&
1645 !tbase_get_deferrable(timer->base))
1646 new_base->next_timer = timer->expires;
1647 internal_add_timer(new_base, timer);
1651 static void __cpuinit migrate_timers(int cpu)
1653 struct tvec_base *old_base;
1654 struct tvec_base *new_base;
1657 BUG_ON(cpu_online(cpu));
1658 old_base = per_cpu(tvec_bases, cpu);
1659 new_base = get_cpu_var(tvec_bases);
1661 * The caller is globally serialized and nobody else
1662 * takes two locks at once, deadlock is not possible.
1664 spin_lock_irq(&new_base->lock);
1665 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1667 BUG_ON(old_base->running_timer);
1669 for (i = 0; i < TVR_SIZE; i++)
1670 migrate_timer_list(new_base, old_base->tv1.vec + i);
1671 for (i = 0; i < TVN_SIZE; i++) {
1672 migrate_timer_list(new_base, old_base->tv2.vec + i);
1673 migrate_timer_list(new_base, old_base->tv3.vec + i);
1674 migrate_timer_list(new_base, old_base->tv4.vec + i);
1675 migrate_timer_list(new_base, old_base->tv5.vec + i);
1678 spin_unlock(&old_base->lock);
1679 spin_unlock_irq(&new_base->lock);
1680 put_cpu_var(tvec_bases);
1682 #endif /* CONFIG_HOTPLUG_CPU */
1684 static int __cpuinit timer_cpu_notify(struct notifier_block *self,
1685 unsigned long action, void *hcpu)
1687 long cpu = (long)hcpu;
1691 case CPU_UP_PREPARE:
1692 case CPU_UP_PREPARE_FROZEN:
1693 err = init_timers_cpu(cpu);
1695 return notifier_from_errno(err);
1697 #ifdef CONFIG_HOTPLUG_CPU
1699 case CPU_DEAD_FROZEN:
1700 migrate_timers(cpu);
1709 static struct notifier_block __cpuinitdata timers_nb = {
1710 .notifier_call = timer_cpu_notify,
1714 void __init init_timers(void)
1716 int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
1717 (void *)(long)smp_processor_id());
1721 BUG_ON(err != NOTIFY_OK);
1722 register_cpu_notifier(&timers_nb);
1723 open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
1727 * msleep - sleep safely even with waitqueue interruptions
1728 * @msecs: Time in milliseconds to sleep for
1730 void msleep(unsigned int msecs)
1732 unsigned long timeout = msecs_to_jiffies(msecs) + 1;
1735 timeout = schedule_timeout_uninterruptible(timeout);
1738 EXPORT_SYMBOL(msleep);
1741 * msleep_interruptible - sleep waiting for signals
1742 * @msecs: Time in milliseconds to sleep for
1744 unsigned long msleep_interruptible(unsigned int msecs)
1746 unsigned long timeout = msecs_to_jiffies(msecs) + 1;
1748 while (timeout && !signal_pending(current))
1749 timeout = schedule_timeout_interruptible(timeout);
1750 return jiffies_to_msecs(timeout);
1753 EXPORT_SYMBOL(msleep_interruptible);
1755 static int __sched do_usleep_range(unsigned long min, unsigned long max)
1758 unsigned long delta;
1760 kmin = ktime_set(0, min * NSEC_PER_USEC);
1761 delta = (max - min) * NSEC_PER_USEC;
1762 return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
1766 * usleep_range - Drop in replacement for udelay where wakeup is flexible
1767 * @min: Minimum time in usecs to sleep
1768 * @max: Maximum time in usecs to sleep
1770 void usleep_range(unsigned long min, unsigned long max)
1772 __set_current_state(TASK_UNINTERRUPTIBLE);
1773 do_usleep_range(min, max);
1775 EXPORT_SYMBOL(usleep_range);