eCryptfs: Copy lower directory inode times and size on link
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / timer.c
blobc61a7949387f93e69b1a4979eff1a03c7e7131b4
1 /*
2 * linux/kernel/timer.c
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>
27 #include <linux/mm.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>
43 #include <asm/uaccess.h>
44 #include <asm/unistd.h>
45 #include <asm/div64.h>
46 #include <asm/timex.h>
47 #include <asm/io.h>
49 #define CREATE_TRACE_POINTS
50 #include <trace/events/timer.h>
52 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
54 EXPORT_SYMBOL(jiffies_64);
57 * per-CPU timer vector definitions:
59 #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
60 #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
61 #define TVN_SIZE (1 << TVN_BITS)
62 #define TVR_SIZE (1 << TVR_BITS)
63 #define TVN_MASK (TVN_SIZE - 1)
64 #define TVR_MASK (TVR_SIZE - 1)
66 struct tvec {
67 struct list_head vec[TVN_SIZE];
70 struct tvec_root {
71 struct list_head vec[TVR_SIZE];
74 struct tvec_base {
75 spinlock_t lock;
76 struct timer_list *running_timer;
77 unsigned long timer_jiffies;
78 unsigned long next_timer;
79 struct tvec_root tv1;
80 struct tvec tv2;
81 struct tvec tv3;
82 struct tvec tv4;
83 struct tvec tv5;
84 } ____cacheline_aligned;
86 struct tvec_base boot_tvec_bases;
87 EXPORT_SYMBOL(boot_tvec_bases);
88 static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
91 * Note that all tvec_bases are 2 byte aligned and lower bit of
92 * base in timer_list is guaranteed to be zero. Use the LSB for
93 * the new flag to indicate whether the timer is deferrable
95 #define TBASE_DEFERRABLE_FLAG (0x1)
97 /* Functions below help us manage 'deferrable' flag */
98 static inline unsigned int tbase_get_deferrable(struct tvec_base *base)
100 return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG);
103 static inline struct tvec_base *tbase_get_base(struct tvec_base *base)
105 return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG));
108 static inline void timer_set_deferrable(struct timer_list *timer)
110 timer->base = ((struct tvec_base *)((unsigned long)(timer->base) |
111 TBASE_DEFERRABLE_FLAG));
114 static inline void
115 timer_set_base(struct timer_list *timer, struct tvec_base *new_base)
117 timer->base = (struct tvec_base *)((unsigned long)(new_base) |
118 tbase_get_deferrable(timer->base));
121 static unsigned long round_jiffies_common(unsigned long j, int cpu,
122 bool force_up)
124 int rem;
125 unsigned long original = j;
128 * We don't want all cpus firing their timers at once hitting the
129 * same lock or cachelines, so we skew each extra cpu with an extra
130 * 3 jiffies. This 3 jiffies came originally from the mm/ code which
131 * already did this.
132 * The skew is done by adding 3*cpunr, then round, then subtract this
133 * extra offset again.
135 j += cpu * 3;
137 rem = j % HZ;
140 * If the target jiffie is just after a whole second (which can happen
141 * due to delays of the timer irq, long irq off times etc etc) then
142 * we should round down to the whole second, not up. Use 1/4th second
143 * as cutoff for this rounding as an extreme upper bound for this.
144 * But never round down if @force_up is set.
146 if (rem < HZ/4 && !force_up) /* round down */
147 j = j - rem;
148 else /* round up */
149 j = j - rem + HZ;
151 /* now that we have rounded, subtract the extra skew again */
152 j -= cpu * 3;
154 if (j <= jiffies) /* rounding ate our timeout entirely; */
155 return original;
156 return j;
160 * __round_jiffies - function to round jiffies to a full second
161 * @j: the time in (absolute) jiffies that should be rounded
162 * @cpu: the processor number on which the timeout will happen
164 * __round_jiffies() rounds an absolute time in the future (in jiffies)
165 * up or down to (approximately) full seconds. This is useful for timers
166 * for which the exact time they fire does not matter too much, as long as
167 * they fire approximately every X seconds.
169 * By rounding these timers to whole seconds, all such timers will fire
170 * at the same time, rather than at various times spread out. The goal
171 * of this is to have the CPU wake up less, which saves power.
173 * The exact rounding is skewed for each processor to avoid all
174 * processors firing at the exact same time, which could lead
175 * to lock contention or spurious cache line bouncing.
177 * The return value is the rounded version of the @j parameter.
179 unsigned long __round_jiffies(unsigned long j, int cpu)
181 return round_jiffies_common(j, cpu, false);
183 EXPORT_SYMBOL_GPL(__round_jiffies);
186 * __round_jiffies_relative - function to round jiffies to a full second
187 * @j: the time in (relative) jiffies that should be rounded
188 * @cpu: the processor number on which the timeout will happen
190 * __round_jiffies_relative() rounds a time delta in the future (in jiffies)
191 * up or down to (approximately) full seconds. This is useful for timers
192 * for which the exact time they fire does not matter too much, as long as
193 * they fire approximately every X seconds.
195 * By rounding these timers to whole seconds, all such timers will fire
196 * at the same time, rather than at various times spread out. The goal
197 * of this is to have the CPU wake up less, which saves power.
199 * The exact rounding is skewed for each processor to avoid all
200 * processors firing at the exact same time, which could lead
201 * to lock contention or spurious cache line bouncing.
203 * The return value is the rounded version of the @j parameter.
205 unsigned long __round_jiffies_relative(unsigned long j, int cpu)
207 unsigned long j0 = jiffies;
209 /* Use j0 because jiffies might change while we run */
210 return round_jiffies_common(j + j0, cpu, false) - j0;
212 EXPORT_SYMBOL_GPL(__round_jiffies_relative);
215 * round_jiffies - function to round jiffies to a full second
216 * @j: the time in (absolute) jiffies that should be rounded
218 * round_jiffies() rounds an absolute time in the future (in jiffies)
219 * up or down to (approximately) full seconds. This is useful for timers
220 * for which the exact time they fire does not matter too much, as long as
221 * they fire approximately every X seconds.
223 * By rounding these timers to whole seconds, all such timers will fire
224 * at the same time, rather than at various times spread out. The goal
225 * of this is to have the CPU wake up less, which saves power.
227 * The return value is the rounded version of the @j parameter.
229 unsigned long round_jiffies(unsigned long j)
231 return round_jiffies_common(j, raw_smp_processor_id(), false);
233 EXPORT_SYMBOL_GPL(round_jiffies);
236 * round_jiffies_relative - function to round jiffies to a full second
237 * @j: the time in (relative) jiffies that should be rounded
239 * round_jiffies_relative() rounds a time delta in the future (in jiffies)
240 * up or down to (approximately) full seconds. This is useful for timers
241 * for which the exact time they fire does not matter too much, as long as
242 * they fire approximately every X seconds.
244 * By rounding these timers to whole seconds, all such timers will fire
245 * at the same time, rather than at various times spread out. The goal
246 * of this is to have the CPU wake up less, which saves power.
248 * The return value is the rounded version of the @j parameter.
250 unsigned long round_jiffies_relative(unsigned long j)
252 return __round_jiffies_relative(j, raw_smp_processor_id());
254 EXPORT_SYMBOL_GPL(round_jiffies_relative);
257 * __round_jiffies_up - function to round jiffies up to a full second
258 * @j: the time in (absolute) jiffies that should be rounded
259 * @cpu: the processor number on which the timeout will happen
261 * This is the same as __round_jiffies() except that it will never
262 * round down. This is useful for timeouts for which the exact time
263 * of firing does not matter too much, as long as they don't fire too
264 * early.
266 unsigned long __round_jiffies_up(unsigned long j, int cpu)
268 return round_jiffies_common(j, cpu, true);
270 EXPORT_SYMBOL_GPL(__round_jiffies_up);
273 * __round_jiffies_up_relative - function to round jiffies up to a full second
274 * @j: the time in (relative) jiffies that should be rounded
275 * @cpu: the processor number on which the timeout will happen
277 * This is the same as __round_jiffies_relative() except that it will never
278 * round down. This is useful for timeouts for which the exact time
279 * of firing does not matter too much, as long as they don't fire too
280 * early.
282 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu)
284 unsigned long j0 = jiffies;
286 /* Use j0 because jiffies might change while we run */
287 return round_jiffies_common(j + j0, cpu, true) - j0;
289 EXPORT_SYMBOL_GPL(__round_jiffies_up_relative);
292 * round_jiffies_up - function to round jiffies up to a full second
293 * @j: the time in (absolute) jiffies that should be rounded
295 * This is the same as round_jiffies() except that it will never
296 * round down. This is useful for timeouts for which the exact time
297 * of firing does not matter too much, as long as they don't fire too
298 * early.
300 unsigned long round_jiffies_up(unsigned long j)
302 return round_jiffies_common(j, raw_smp_processor_id(), true);
304 EXPORT_SYMBOL_GPL(round_jiffies_up);
307 * round_jiffies_up_relative - function to round jiffies up to a full second
308 * @j: the time in (relative) jiffies that should be rounded
310 * This is the same as round_jiffies_relative() except that it will never
311 * round down. This is useful for timeouts for which the exact time
312 * of firing does not matter too much, as long as they don't fire too
313 * early.
315 unsigned long round_jiffies_up_relative(unsigned long j)
317 return __round_jiffies_up_relative(j, raw_smp_processor_id());
319 EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
322 static inline void set_running_timer(struct tvec_base *base,
323 struct timer_list *timer)
325 #ifdef CONFIG_SMP
326 base->running_timer = timer;
327 #endif
330 static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
332 unsigned long expires = timer->expires;
333 unsigned long idx = expires - base->timer_jiffies;
334 struct list_head *vec;
336 if (idx < TVR_SIZE) {
337 int i = expires & TVR_MASK;
338 vec = base->tv1.vec + i;
339 } else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
340 int i = (expires >> TVR_BITS) & TVN_MASK;
341 vec = base->tv2.vec + i;
342 } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
343 int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
344 vec = base->tv3.vec + i;
345 } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
346 int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
347 vec = base->tv4.vec + i;
348 } else if ((signed long) idx < 0) {
350 * Can happen if you add a timer with expires == jiffies,
351 * or you set a timer to go off in the past
353 vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK);
354 } else {
355 int i;
356 /* If the timeout is larger than 0xffffffff on 64-bit
357 * architectures then we use the maximum timeout:
359 if (idx > 0xffffffffUL) {
360 idx = 0xffffffffUL;
361 expires = idx + base->timer_jiffies;
363 i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
364 vec = base->tv5.vec + i;
367 * Timers are FIFO:
369 list_add_tail(&timer->entry, vec);
372 #ifdef CONFIG_TIMER_STATS
373 void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
375 if (timer->start_site)
376 return;
378 timer->start_site = addr;
379 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
380 timer->start_pid = current->pid;
383 static void timer_stats_account_timer(struct timer_list *timer)
385 unsigned int flag = 0;
387 if (likely(!timer->start_site))
388 return;
389 if (unlikely(tbase_get_deferrable(timer->base)))
390 flag |= TIMER_STATS_FLAG_DEFERRABLE;
392 timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
393 timer->function, timer->start_comm, flag);
396 #else
397 static void timer_stats_account_timer(struct timer_list *timer) {}
398 #endif
400 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
402 static struct debug_obj_descr timer_debug_descr;
405 * fixup_init is called when:
406 * - an active object is initialized
408 static int timer_fixup_init(void *addr, enum debug_obj_state state)
410 struct timer_list *timer = addr;
412 switch (state) {
413 case ODEBUG_STATE_ACTIVE:
414 del_timer_sync(timer);
415 debug_object_init(timer, &timer_debug_descr);
416 return 1;
417 default:
418 return 0;
423 * fixup_activate is called when:
424 * - an active object is activated
425 * - an unknown object is activated (might be a statically initialized object)
427 static int timer_fixup_activate(void *addr, enum debug_obj_state state)
429 struct timer_list *timer = addr;
431 switch (state) {
433 case ODEBUG_STATE_NOTAVAILABLE:
435 * This is not really a fixup. The timer was
436 * statically initialized. We just make sure that it
437 * is tracked in the object tracker.
439 if (timer->entry.next == NULL &&
440 timer->entry.prev == TIMER_ENTRY_STATIC) {
441 debug_object_init(timer, &timer_debug_descr);
442 debug_object_activate(timer, &timer_debug_descr);
443 return 0;
444 } else {
445 WARN_ON_ONCE(1);
447 return 0;
449 case ODEBUG_STATE_ACTIVE:
450 WARN_ON(1);
452 default:
453 return 0;
458 * fixup_free is called when:
459 * - an active object is freed
461 static int timer_fixup_free(void *addr, enum debug_obj_state state)
463 struct timer_list *timer = addr;
465 switch (state) {
466 case ODEBUG_STATE_ACTIVE:
467 del_timer_sync(timer);
468 debug_object_free(timer, &timer_debug_descr);
469 return 1;
470 default:
471 return 0;
475 static struct debug_obj_descr timer_debug_descr = {
476 .name = "timer_list",
477 .fixup_init = timer_fixup_init,
478 .fixup_activate = timer_fixup_activate,
479 .fixup_free = timer_fixup_free,
482 static inline void debug_timer_init(struct timer_list *timer)
484 debug_object_init(timer, &timer_debug_descr);
487 static inline void debug_timer_activate(struct timer_list *timer)
489 debug_object_activate(timer, &timer_debug_descr);
492 static inline void debug_timer_deactivate(struct timer_list *timer)
494 debug_object_deactivate(timer, &timer_debug_descr);
497 static inline void debug_timer_free(struct timer_list *timer)
499 debug_object_free(timer, &timer_debug_descr);
502 static void __init_timer(struct timer_list *timer,
503 const char *name,
504 struct lock_class_key *key);
506 void init_timer_on_stack_key(struct timer_list *timer,
507 const char *name,
508 struct lock_class_key *key)
510 debug_object_init_on_stack(timer, &timer_debug_descr);
511 __init_timer(timer, name, key);
513 EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
515 void destroy_timer_on_stack(struct timer_list *timer)
517 debug_object_free(timer, &timer_debug_descr);
519 EXPORT_SYMBOL_GPL(destroy_timer_on_stack);
521 #else
522 static inline void debug_timer_init(struct timer_list *timer) { }
523 static inline void debug_timer_activate(struct timer_list *timer) { }
524 static inline void debug_timer_deactivate(struct timer_list *timer) { }
525 #endif
527 static inline void debug_init(struct timer_list *timer)
529 debug_timer_init(timer);
530 trace_timer_init(timer);
533 static inline void
534 debug_activate(struct timer_list *timer, unsigned long expires)
536 debug_timer_activate(timer);
537 trace_timer_start(timer, expires);
540 static inline void debug_deactivate(struct timer_list *timer)
542 debug_timer_deactivate(timer);
543 trace_timer_cancel(timer);
546 static void __init_timer(struct timer_list *timer,
547 const char *name,
548 struct lock_class_key *key)
550 timer->entry.next = NULL;
551 timer->base = __raw_get_cpu_var(tvec_bases);
552 #ifdef CONFIG_TIMER_STATS
553 timer->start_site = NULL;
554 timer->start_pid = -1;
555 memset(timer->start_comm, 0, TASK_COMM_LEN);
556 #endif
557 lockdep_init_map(&timer->lockdep_map, name, key, 0);
561 * init_timer_key - initialize a timer
562 * @timer: the timer to be initialized
563 * @name: name of the timer
564 * @key: lockdep class key of the fake lock used for tracking timer
565 * sync lock dependencies
567 * init_timer_key() must be done to a timer prior calling *any* of the
568 * other timer functions.
570 void init_timer_key(struct timer_list *timer,
571 const char *name,
572 struct lock_class_key *key)
574 debug_init(timer);
575 __init_timer(timer, name, key);
577 EXPORT_SYMBOL(init_timer_key);
579 void init_timer_deferrable_key(struct timer_list *timer,
580 const char *name,
581 struct lock_class_key *key)
583 init_timer_key(timer, name, key);
584 timer_set_deferrable(timer);
586 EXPORT_SYMBOL(init_timer_deferrable_key);
588 static inline void detach_timer(struct timer_list *timer,
589 int clear_pending)
591 struct list_head *entry = &timer->entry;
593 debug_deactivate(timer);
595 __list_del(entry->prev, entry->next);
596 if (clear_pending)
597 entry->next = NULL;
598 entry->prev = LIST_POISON2;
602 * We are using hashed locking: holding per_cpu(tvec_bases).lock
603 * means that all timers which are tied to this base via timer->base are
604 * locked, and the base itself is locked too.
606 * So __run_timers/migrate_timers can safely modify all timers which could
607 * be found on ->tvX lists.
609 * When the timer's base is locked, and the timer removed from list, it is
610 * possible to set timer->base = NULL and drop the lock: the timer remains
611 * locked.
613 static struct tvec_base *lock_timer_base(struct timer_list *timer,
614 unsigned long *flags)
615 __acquires(timer->base->lock)
617 struct tvec_base *base;
619 for (;;) {
620 struct tvec_base *prelock_base = timer->base;
621 base = tbase_get_base(prelock_base);
622 if (likely(base != NULL)) {
623 spin_lock_irqsave(&base->lock, *flags);
624 if (likely(prelock_base == timer->base))
625 return base;
626 /* The timer has migrated to another CPU */
627 spin_unlock_irqrestore(&base->lock, *flags);
629 cpu_relax();
633 static inline int
634 __mod_timer(struct timer_list *timer, unsigned long expires,
635 bool pending_only, int pinned)
637 struct tvec_base *base, *new_base;
638 unsigned long flags;
639 int ret = 0 , cpu;
641 timer_stats_timer_set_start_info(timer);
642 BUG_ON(!timer->function);
644 base = lock_timer_base(timer, &flags);
646 if (timer_pending(timer)) {
647 detach_timer(timer, 0);
648 if (timer->expires == base->next_timer &&
649 !tbase_get_deferrable(timer->base))
650 base->next_timer = base->timer_jiffies;
651 ret = 1;
652 } else {
653 if (pending_only)
654 goto out_unlock;
657 debug_activate(timer, expires);
659 cpu = smp_processor_id();
661 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
662 if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) {
663 int preferred_cpu = get_nohz_load_balancer();
665 if (preferred_cpu >= 0)
666 cpu = preferred_cpu;
668 #endif
669 new_base = per_cpu(tvec_bases, cpu);
671 if (base != new_base) {
673 * We are trying to schedule the timer on the local CPU.
674 * However we can't change timer's base while it is running,
675 * otherwise del_timer_sync() can't detect that the timer's
676 * handler yet has not finished. This also guarantees that
677 * the timer is serialized wrt itself.
679 if (likely(base->running_timer != timer)) {
680 /* See the comment in lock_timer_base() */
681 timer_set_base(timer, NULL);
682 spin_unlock(&base->lock);
683 base = new_base;
684 spin_lock(&base->lock);
685 timer_set_base(timer, base);
689 timer->expires = expires;
690 if (time_before(timer->expires, base->next_timer) &&
691 !tbase_get_deferrable(timer->base))
692 base->next_timer = timer->expires;
693 internal_add_timer(base, timer);
695 out_unlock:
696 spin_unlock_irqrestore(&base->lock, flags);
698 return ret;
702 * mod_timer_pending - modify a pending timer's timeout
703 * @timer: the pending timer to be modified
704 * @expires: new timeout in jiffies
706 * mod_timer_pending() is the same for pending timers as mod_timer(),
707 * but will not re-activate and modify already deleted timers.
709 * It is useful for unserialized use of timers.
711 int mod_timer_pending(struct timer_list *timer, unsigned long expires)
713 return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
715 EXPORT_SYMBOL(mod_timer_pending);
718 * mod_timer - modify a timer's timeout
719 * @timer: the timer to be modified
720 * @expires: new timeout in jiffies
722 * mod_timer() is a more efficient way to update the expire field of an
723 * active timer (if the timer is inactive it will be activated)
725 * mod_timer(timer, expires) is equivalent to:
727 * del_timer(timer); timer->expires = expires; add_timer(timer);
729 * Note that if there are multiple unserialized concurrent users of the
730 * same timer, then mod_timer() is the only safe way to modify the timeout,
731 * since add_timer() cannot modify an already running timer.
733 * The function returns whether it has modified a pending timer or not.
734 * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
735 * active timer returns 1.)
737 int mod_timer(struct timer_list *timer, unsigned long expires)
740 * This is a common optimization triggered by the
741 * networking code - if the timer is re-modified
742 * to be the same thing then just return:
744 if (timer_pending(timer) && timer->expires == expires)
745 return 1;
747 return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
749 EXPORT_SYMBOL(mod_timer);
752 * mod_timer_pinned - modify a timer's timeout
753 * @timer: the timer to be modified
754 * @expires: new timeout in jiffies
756 * mod_timer_pinned() is a way to update the expire field of an
757 * active timer (if the timer is inactive it will be activated)
758 * and not allow the timer to be migrated to a different CPU.
760 * mod_timer_pinned(timer, expires) is equivalent to:
762 * del_timer(timer); timer->expires = expires; add_timer(timer);
764 int mod_timer_pinned(struct timer_list *timer, unsigned long expires)
766 if (timer->expires == expires && timer_pending(timer))
767 return 1;
769 return __mod_timer(timer, expires, false, TIMER_PINNED);
771 EXPORT_SYMBOL(mod_timer_pinned);
774 * add_timer - start a timer
775 * @timer: the timer to be added
777 * The kernel will do a ->function(->data) callback from the
778 * timer interrupt at the ->expires point in the future. The
779 * current time is 'jiffies'.
781 * The timer's ->expires, ->function (and if the handler uses it, ->data)
782 * fields must be set prior calling this function.
784 * Timers with an ->expires field in the past will be executed in the next
785 * timer tick.
787 void add_timer(struct timer_list *timer)
789 BUG_ON(timer_pending(timer));
790 mod_timer(timer, timer->expires);
792 EXPORT_SYMBOL(add_timer);
795 * add_timer_on - start a timer on a particular CPU
796 * @timer: the timer to be added
797 * @cpu: the CPU to start it on
799 * This is not very scalable on SMP. Double adds are not possible.
801 void add_timer_on(struct timer_list *timer, int cpu)
803 struct tvec_base *base = per_cpu(tvec_bases, cpu);
804 unsigned long flags;
806 timer_stats_timer_set_start_info(timer);
807 BUG_ON(timer_pending(timer) || !timer->function);
808 spin_lock_irqsave(&base->lock, flags);
809 timer_set_base(timer, base);
810 debug_activate(timer, timer->expires);
811 if (time_before(timer->expires, base->next_timer) &&
812 !tbase_get_deferrable(timer->base))
813 base->next_timer = timer->expires;
814 internal_add_timer(base, timer);
816 * Check whether the other CPU is idle and needs to be
817 * triggered to reevaluate the timer wheel when nohz is
818 * active. We are protected against the other CPU fiddling
819 * with the timer by holding the timer base lock. This also
820 * makes sure that a CPU on the way to idle can not evaluate
821 * the timer wheel.
823 wake_up_idle_cpu(cpu);
824 spin_unlock_irqrestore(&base->lock, flags);
826 EXPORT_SYMBOL_GPL(add_timer_on);
829 * del_timer - deactive a timer.
830 * @timer: the timer to be deactivated
832 * del_timer() deactivates a timer - this works on both active and inactive
833 * timers.
835 * The function returns whether it has deactivated a pending timer or not.
836 * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
837 * active timer returns 1.)
839 int del_timer(struct timer_list *timer)
841 struct tvec_base *base;
842 unsigned long flags;
843 int ret = 0;
845 timer_stats_timer_clear_start_info(timer);
846 if (timer_pending(timer)) {
847 base = lock_timer_base(timer, &flags);
848 if (timer_pending(timer)) {
849 detach_timer(timer, 1);
850 if (timer->expires == base->next_timer &&
851 !tbase_get_deferrable(timer->base))
852 base->next_timer = base->timer_jiffies;
853 ret = 1;
855 spin_unlock_irqrestore(&base->lock, flags);
858 return ret;
860 EXPORT_SYMBOL(del_timer);
862 #ifdef CONFIG_SMP
864 * try_to_del_timer_sync - Try to deactivate a timer
865 * @timer: timer do del
867 * This function tries to deactivate a timer. Upon successful (ret >= 0)
868 * exit the timer is not queued and the handler is not running on any CPU.
870 * It must not be called from interrupt contexts.
872 int try_to_del_timer_sync(struct timer_list *timer)
874 struct tvec_base *base;
875 unsigned long flags;
876 int ret = -1;
878 base = lock_timer_base(timer, &flags);
880 if (base->running_timer == timer)
881 goto out;
883 ret = 0;
884 if (timer_pending(timer)) {
885 detach_timer(timer, 1);
886 if (timer->expires == base->next_timer &&
887 !tbase_get_deferrable(timer->base))
888 base->next_timer = base->timer_jiffies;
889 ret = 1;
891 out:
892 spin_unlock_irqrestore(&base->lock, flags);
894 return ret;
896 EXPORT_SYMBOL(try_to_del_timer_sync);
899 * del_timer_sync - deactivate a timer and wait for the handler to finish.
900 * @timer: the timer to be deactivated
902 * This function only differs from del_timer() on SMP: besides deactivating
903 * the timer it also makes sure the handler has finished executing on other
904 * CPUs.
906 * Synchronization rules: Callers must prevent restarting of the timer,
907 * otherwise this function is meaningless. It must not be called from
908 * interrupt contexts. The caller must not hold locks which would prevent
909 * completion of the timer's handler. The timer's handler must not call
910 * add_timer_on(). Upon exit the timer is not queued and the handler is
911 * not running on any CPU.
913 * The function returns whether it has deactivated a pending timer or not.
915 int del_timer_sync(struct timer_list *timer)
917 #ifdef CONFIG_LOCKDEP
918 unsigned long flags;
920 local_irq_save(flags);
921 lock_map_acquire(&timer->lockdep_map);
922 lock_map_release(&timer->lockdep_map);
923 local_irq_restore(flags);
924 #endif
926 for (;;) {
927 int ret = try_to_del_timer_sync(timer);
928 if (ret >= 0)
929 return ret;
930 cpu_relax();
933 EXPORT_SYMBOL(del_timer_sync);
934 #endif
936 static int cascade(struct tvec_base *base, struct tvec *tv, int index)
938 /* cascade all the timers from tv up one level */
939 struct timer_list *timer, *tmp;
940 struct list_head tv_list;
942 list_replace_init(tv->vec + index, &tv_list);
945 * We are removing _all_ timers from the list, so we
946 * don't have to detach them individually.
948 list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
949 BUG_ON(tbase_get_base(timer->base) != base);
950 internal_add_timer(base, timer);
953 return index;
956 #define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
959 * __run_timers - run all expired timers (if any) on this CPU.
960 * @base: the timer vector to be processed.
962 * This function cascades all vectors and executes all expired timer
963 * vectors.
965 static inline void __run_timers(struct tvec_base *base)
967 struct timer_list *timer;
969 spin_lock_irq(&base->lock);
970 while (time_after_eq(jiffies, base->timer_jiffies)) {
971 struct list_head work_list;
972 struct list_head *head = &work_list;
973 int index = base->timer_jiffies & TVR_MASK;
976 * Cascade timers:
978 if (!index &&
979 (!cascade(base, &base->tv2, INDEX(0))) &&
980 (!cascade(base, &base->tv3, INDEX(1))) &&
981 !cascade(base, &base->tv4, INDEX(2)))
982 cascade(base, &base->tv5, INDEX(3));
983 ++base->timer_jiffies;
984 list_replace_init(base->tv1.vec + index, &work_list);
985 while (!list_empty(head)) {
986 void (*fn)(unsigned long);
987 unsigned long data;
989 timer = list_first_entry(head, struct timer_list,entry);
990 fn = timer->function;
991 data = timer->data;
993 timer_stats_account_timer(timer);
995 set_running_timer(base, timer);
996 detach_timer(timer, 1);
998 spin_unlock_irq(&base->lock);
1000 int preempt_count = preempt_count();
1002 #ifdef CONFIG_LOCKDEP
1004 * It is permissible to free the timer from
1005 * inside the function that is called from
1006 * it, this we need to take into account for
1007 * lockdep too. To avoid bogus "held lock
1008 * freed" warnings as well as problems when
1009 * looking into timer->lockdep_map, make a
1010 * copy and use that here.
1012 struct lockdep_map lockdep_map =
1013 timer->lockdep_map;
1014 #endif
1016 * Couple the lock chain with the lock chain at
1017 * del_timer_sync() by acquiring the lock_map
1018 * around the fn() call here and in
1019 * del_timer_sync().
1021 lock_map_acquire(&lockdep_map);
1023 trace_timer_expire_entry(timer);
1024 fn(data);
1025 trace_timer_expire_exit(timer);
1027 lock_map_release(&lockdep_map);
1029 if (preempt_count != preempt_count()) {
1030 printk(KERN_ERR "huh, entered %p "
1031 "with preempt_count %08x, exited"
1032 " with %08x?\n",
1033 fn, preempt_count,
1034 preempt_count());
1035 BUG();
1038 spin_lock_irq(&base->lock);
1041 set_running_timer(base, NULL);
1042 spin_unlock_irq(&base->lock);
1045 #ifdef CONFIG_NO_HZ
1047 * Find out when the next timer event is due to happen. This
1048 * is used on S/390 to stop all activity when a CPU is idle.
1049 * This function needs to be called with interrupts disabled.
1051 static unsigned long __next_timer_interrupt(struct tvec_base *base)
1053 unsigned long timer_jiffies = base->timer_jiffies;
1054 unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA;
1055 int index, slot, array, found = 0;
1056 struct timer_list *nte;
1057 struct tvec *varray[4];
1059 /* Look for timer events in tv1. */
1060 index = slot = timer_jiffies & TVR_MASK;
1061 do {
1062 list_for_each_entry(nte, base->tv1.vec + slot, entry) {
1063 if (tbase_get_deferrable(nte->base))
1064 continue;
1066 found = 1;
1067 expires = nte->expires;
1068 /* Look at the cascade bucket(s)? */
1069 if (!index || slot < index)
1070 goto cascade;
1071 return expires;
1073 slot = (slot + 1) & TVR_MASK;
1074 } while (slot != index);
1076 cascade:
1077 /* Calculate the next cascade event */
1078 if (index)
1079 timer_jiffies += TVR_SIZE - index;
1080 timer_jiffies >>= TVR_BITS;
1082 /* Check tv2-tv5. */
1083 varray[0] = &base->tv2;
1084 varray[1] = &base->tv3;
1085 varray[2] = &base->tv4;
1086 varray[3] = &base->tv5;
1088 for (array = 0; array < 4; array++) {
1089 struct tvec *varp = varray[array];
1091 index = slot = timer_jiffies & TVN_MASK;
1092 do {
1093 list_for_each_entry(nte, varp->vec + slot, entry) {
1094 if (tbase_get_deferrable(nte->base))
1095 continue;
1097 found = 1;
1098 if (time_before(nte->expires, expires))
1099 expires = nte->expires;
1102 * Do we still search for the first timer or are
1103 * we looking up the cascade buckets ?
1105 if (found) {
1106 /* Look at the cascade bucket(s)? */
1107 if (!index || slot < index)
1108 break;
1109 return expires;
1111 slot = (slot + 1) & TVN_MASK;
1112 } while (slot != index);
1114 if (index)
1115 timer_jiffies += TVN_SIZE - index;
1116 timer_jiffies >>= TVN_BITS;
1118 return expires;
1122 * Check, if the next hrtimer event is before the next timer wheel
1123 * event:
1125 static unsigned long cmp_next_hrtimer_event(unsigned long now,
1126 unsigned long expires)
1128 ktime_t hr_delta = hrtimer_get_next_event();
1129 struct timespec tsdelta;
1130 unsigned long delta;
1132 if (hr_delta.tv64 == KTIME_MAX)
1133 return expires;
1136 * Expired timer available, let it expire in the next tick
1138 if (hr_delta.tv64 <= 0)
1139 return now + 1;
1141 tsdelta = ktime_to_timespec(hr_delta);
1142 delta = timespec_to_jiffies(&tsdelta);
1145 * Limit the delta to the max value, which is checked in
1146 * tick_nohz_stop_sched_tick():
1148 if (delta > NEXT_TIMER_MAX_DELTA)
1149 delta = NEXT_TIMER_MAX_DELTA;
1152 * Take rounding errors in to account and make sure, that it
1153 * expires in the next tick. Otherwise we go into an endless
1154 * ping pong due to tick_nohz_stop_sched_tick() retriggering
1155 * the timer softirq
1157 if (delta < 1)
1158 delta = 1;
1159 now += delta;
1160 if (time_before(now, expires))
1161 return now;
1162 return expires;
1166 * get_next_timer_interrupt - return the jiffy of the next pending timer
1167 * @now: current time (in jiffies)
1169 unsigned long get_next_timer_interrupt(unsigned long now)
1171 struct tvec_base *base = __get_cpu_var(tvec_bases);
1172 unsigned long expires;
1174 spin_lock(&base->lock);
1175 if (time_before_eq(base->next_timer, base->timer_jiffies))
1176 base->next_timer = __next_timer_interrupt(base);
1177 expires = base->next_timer;
1178 spin_unlock(&base->lock);
1180 if (time_before_eq(expires, now))
1181 return now;
1183 return cmp_next_hrtimer_event(now, expires);
1185 #endif
1188 * Called from the timer interrupt handler to charge one tick to the current
1189 * process. user_tick is 1 if the tick is user time, 0 for system.
1191 void update_process_times(int user_tick)
1193 struct task_struct *p = current;
1194 int cpu = smp_processor_id();
1196 /* Note: this timer irq context must be accounted for as well. */
1197 account_process_tick(p, user_tick);
1198 run_local_timers();
1199 rcu_check_callbacks(cpu, user_tick);
1200 printk_tick();
1201 perf_event_do_pending();
1202 scheduler_tick();
1203 run_posix_cpu_timers(p);
1207 * This function runs timers and the timer-tq in bottom half context.
1209 static void run_timer_softirq(struct softirq_action *h)
1211 struct tvec_base *base = __get_cpu_var(tvec_bases);
1213 hrtimer_run_pending();
1215 if (time_after_eq(jiffies, base->timer_jiffies))
1216 __run_timers(base);
1220 * Called by the local, per-CPU timer interrupt on SMP.
1222 void run_local_timers(void)
1224 hrtimer_run_queues();
1225 raise_softirq(TIMER_SOFTIRQ);
1226 softlockup_tick();
1230 * The 64-bit jiffies value is not atomic - you MUST NOT read it
1231 * without sampling the sequence number in xtime_lock.
1232 * jiffies is defined in the linker script...
1235 void do_timer(unsigned long ticks)
1237 jiffies_64 += ticks;
1238 update_wall_time();
1239 calc_global_load();
1242 #ifdef __ARCH_WANT_SYS_ALARM
1245 * For backwards compatibility? This can be done in libc so Alpha
1246 * and all newer ports shouldn't need it.
1248 SYSCALL_DEFINE1(alarm, unsigned int, seconds)
1250 return alarm_setitimer(seconds);
1253 #endif
1255 #ifndef __alpha__
1258 * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this
1259 * should be moved into arch/i386 instead?
1263 * sys_getpid - return the thread group id of the current process
1265 * Note, despite the name, this returns the tgid not the pid. The tgid and
1266 * the pid are identical unless CLONE_THREAD was specified on clone() in
1267 * which case the tgid is the same in all threads of the same group.
1269 * This is SMP safe as current->tgid does not change.
1271 SYSCALL_DEFINE0(getpid)
1273 return task_tgid_vnr(current);
1277 * Accessing ->real_parent is not SMP-safe, it could
1278 * change from under us. However, we can use a stale
1279 * value of ->real_parent under rcu_read_lock(), see
1280 * release_task()->call_rcu(delayed_put_task_struct).
1282 SYSCALL_DEFINE0(getppid)
1284 int pid;
1286 rcu_read_lock();
1287 pid = task_tgid_vnr(current->real_parent);
1288 rcu_read_unlock();
1290 return pid;
1293 SYSCALL_DEFINE0(getuid)
1295 /* Only we change this so SMP safe */
1296 return current_uid();
1299 SYSCALL_DEFINE0(geteuid)
1301 /* Only we change this so SMP safe */
1302 return current_euid();
1305 SYSCALL_DEFINE0(getgid)
1307 /* Only we change this so SMP safe */
1308 return current_gid();
1311 SYSCALL_DEFINE0(getegid)
1313 /* Only we change this so SMP safe */
1314 return current_egid();
1317 #endif
1319 static void process_timeout(unsigned long __data)
1321 wake_up_process((struct task_struct *)__data);
1325 * schedule_timeout - sleep until timeout
1326 * @timeout: timeout value in jiffies
1328 * Make the current task sleep until @timeout jiffies have
1329 * elapsed. The routine will return immediately unless
1330 * the current task state has been set (see set_current_state()).
1332 * You can set the task state as follows -
1334 * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
1335 * pass before the routine returns. The routine will return 0
1337 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1338 * delivered to the current task. In this case the remaining time
1339 * in jiffies will be returned, or 0 if the timer expired in time
1341 * The current task state is guaranteed to be TASK_RUNNING when this
1342 * routine returns.
1344 * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
1345 * the CPU away without a bound on the timeout. In this case the return
1346 * value will be %MAX_SCHEDULE_TIMEOUT.
1348 * In all cases the return value is guaranteed to be non-negative.
1350 signed long __sched schedule_timeout(signed long timeout)
1352 struct timer_list timer;
1353 unsigned long expire;
1355 switch (timeout)
1357 case MAX_SCHEDULE_TIMEOUT:
1359 * These two special cases are useful to be comfortable
1360 * in the caller. Nothing more. We could take
1361 * MAX_SCHEDULE_TIMEOUT from one of the negative value
1362 * but I' d like to return a valid offset (>=0) to allow
1363 * the caller to do everything it want with the retval.
1365 schedule();
1366 goto out;
1367 default:
1369 * Another bit of PARANOID. Note that the retval will be
1370 * 0 since no piece of kernel is supposed to do a check
1371 * for a negative retval of schedule_timeout() (since it
1372 * should never happens anyway). You just have the printk()
1373 * that will tell you if something is gone wrong and where.
1375 if (timeout < 0) {
1376 printk(KERN_ERR "schedule_timeout: wrong timeout "
1377 "value %lx\n", timeout);
1378 dump_stack();
1379 current->state = TASK_RUNNING;
1380 goto out;
1384 expire = timeout + jiffies;
1386 setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
1387 __mod_timer(&timer, expire, false, TIMER_NOT_PINNED);
1388 schedule();
1389 del_singleshot_timer_sync(&timer);
1391 /* Remove the timer from the object tracker */
1392 destroy_timer_on_stack(&timer);
1394 timeout = expire - jiffies;
1396 out:
1397 return timeout < 0 ? 0 : timeout;
1399 EXPORT_SYMBOL(schedule_timeout);
1402 * We can use __set_current_state() here because schedule_timeout() calls
1403 * schedule() unconditionally.
1405 signed long __sched schedule_timeout_interruptible(signed long timeout)
1407 __set_current_state(TASK_INTERRUPTIBLE);
1408 return schedule_timeout(timeout);
1410 EXPORT_SYMBOL(schedule_timeout_interruptible);
1412 signed long __sched schedule_timeout_killable(signed long timeout)
1414 __set_current_state(TASK_KILLABLE);
1415 return schedule_timeout(timeout);
1417 EXPORT_SYMBOL(schedule_timeout_killable);
1419 signed long __sched schedule_timeout_uninterruptible(signed long timeout)
1421 __set_current_state(TASK_UNINTERRUPTIBLE);
1422 return schedule_timeout(timeout);
1424 EXPORT_SYMBOL(schedule_timeout_uninterruptible);
1426 /* Thread ID - the internal kernel "pid" */
1427 SYSCALL_DEFINE0(gettid)
1429 return task_pid_vnr(current);
1433 * do_sysinfo - fill in sysinfo struct
1434 * @info: pointer to buffer to fill
1436 int do_sysinfo(struct sysinfo *info)
1438 unsigned long mem_total, sav_total;
1439 unsigned int mem_unit, bitcount;
1440 struct timespec tp;
1442 memset(info, 0, sizeof(struct sysinfo));
1444 ktime_get_ts(&tp);
1445 monotonic_to_bootbased(&tp);
1446 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
1448 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
1450 info->procs = nr_threads;
1452 si_meminfo(info);
1453 si_swapinfo(info);
1456 * If the sum of all the available memory (i.e. ram + swap)
1457 * is less than can be stored in a 32 bit unsigned long then
1458 * we can be binary compatible with 2.2.x kernels. If not,
1459 * well, in that case 2.2.x was broken anyways...
1461 * -Erik Andersen <andersee@debian.org>
1464 mem_total = info->totalram + info->totalswap;
1465 if (mem_total < info->totalram || mem_total < info->totalswap)
1466 goto out;
1467 bitcount = 0;
1468 mem_unit = info->mem_unit;
1469 while (mem_unit > 1) {
1470 bitcount++;
1471 mem_unit >>= 1;
1472 sav_total = mem_total;
1473 mem_total <<= 1;
1474 if (mem_total < sav_total)
1475 goto out;
1479 * If mem_total did not overflow, multiply all memory values by
1480 * info->mem_unit and set it to 1. This leaves things compatible
1481 * with 2.2.x, and also retains compatibility with earlier 2.4.x
1482 * kernels...
1485 info->mem_unit = 1;
1486 info->totalram <<= bitcount;
1487 info->freeram <<= bitcount;
1488 info->sharedram <<= bitcount;
1489 info->bufferram <<= bitcount;
1490 info->totalswap <<= bitcount;
1491 info->freeswap <<= bitcount;
1492 info->totalhigh <<= bitcount;
1493 info->freehigh <<= bitcount;
1495 out:
1496 return 0;
1499 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
1501 struct sysinfo val;
1503 do_sysinfo(&val);
1505 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
1506 return -EFAULT;
1508 return 0;
1511 static int __cpuinit init_timers_cpu(int cpu)
1513 int j;
1514 struct tvec_base *base;
1515 static char __cpuinitdata tvec_base_done[NR_CPUS];
1517 if (!tvec_base_done[cpu]) {
1518 static char boot_done;
1520 if (boot_done) {
1522 * The APs use this path later in boot
1524 base = kmalloc_node(sizeof(*base),
1525 GFP_KERNEL | __GFP_ZERO,
1526 cpu_to_node(cpu));
1527 if (!base)
1528 return -ENOMEM;
1530 /* Make sure that tvec_base is 2 byte aligned */
1531 if (tbase_get_deferrable(base)) {
1532 WARN_ON(1);
1533 kfree(base);
1534 return -ENOMEM;
1536 per_cpu(tvec_bases, cpu) = base;
1537 } else {
1539 * This is for the boot CPU - we use compile-time
1540 * static initialisation because per-cpu memory isn't
1541 * ready yet and because the memory allocators are not
1542 * initialised either.
1544 boot_done = 1;
1545 base = &boot_tvec_bases;
1547 tvec_base_done[cpu] = 1;
1548 } else {
1549 base = per_cpu(tvec_bases, cpu);
1552 spin_lock_init(&base->lock);
1554 for (j = 0; j < TVN_SIZE; j++) {
1555 INIT_LIST_HEAD(base->tv5.vec + j);
1556 INIT_LIST_HEAD(base->tv4.vec + j);
1557 INIT_LIST_HEAD(base->tv3.vec + j);
1558 INIT_LIST_HEAD(base->tv2.vec + j);
1560 for (j = 0; j < TVR_SIZE; j++)
1561 INIT_LIST_HEAD(base->tv1.vec + j);
1563 base->timer_jiffies = jiffies;
1564 base->next_timer = base->timer_jiffies;
1565 return 0;
1568 #ifdef CONFIG_HOTPLUG_CPU
1569 static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head)
1571 struct timer_list *timer;
1573 while (!list_empty(head)) {
1574 timer = list_first_entry(head, struct timer_list, entry);
1575 detach_timer(timer, 0);
1576 timer_set_base(timer, new_base);
1577 if (time_before(timer->expires, new_base->next_timer) &&
1578 !tbase_get_deferrable(timer->base))
1579 new_base->next_timer = timer->expires;
1580 internal_add_timer(new_base, timer);
1584 static void __cpuinit migrate_timers(int cpu)
1586 struct tvec_base *old_base;
1587 struct tvec_base *new_base;
1588 int i;
1590 BUG_ON(cpu_online(cpu));
1591 old_base = per_cpu(tvec_bases, cpu);
1592 new_base = get_cpu_var(tvec_bases);
1594 * The caller is globally serialized and nobody else
1595 * takes two locks at once, deadlock is not possible.
1597 spin_lock_irq(&new_base->lock);
1598 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1600 BUG_ON(old_base->running_timer);
1602 for (i = 0; i < TVR_SIZE; i++)
1603 migrate_timer_list(new_base, old_base->tv1.vec + i);
1604 for (i = 0; i < TVN_SIZE; i++) {
1605 migrate_timer_list(new_base, old_base->tv2.vec + i);
1606 migrate_timer_list(new_base, old_base->tv3.vec + i);
1607 migrate_timer_list(new_base, old_base->tv4.vec + i);
1608 migrate_timer_list(new_base, old_base->tv5.vec + i);
1611 spin_unlock(&old_base->lock);
1612 spin_unlock_irq(&new_base->lock);
1613 put_cpu_var(tvec_bases);
1615 #endif /* CONFIG_HOTPLUG_CPU */
1617 static int __cpuinit timer_cpu_notify(struct notifier_block *self,
1618 unsigned long action, void *hcpu)
1620 long cpu = (long)hcpu;
1621 switch(action) {
1622 case CPU_UP_PREPARE:
1623 case CPU_UP_PREPARE_FROZEN:
1624 if (init_timers_cpu(cpu) < 0)
1625 return NOTIFY_BAD;
1626 break;
1627 #ifdef CONFIG_HOTPLUG_CPU
1628 case CPU_DEAD:
1629 case CPU_DEAD_FROZEN:
1630 migrate_timers(cpu);
1631 break;
1632 #endif
1633 default:
1634 break;
1636 return NOTIFY_OK;
1639 static struct notifier_block __cpuinitdata timers_nb = {
1640 .notifier_call = timer_cpu_notify,
1644 void __init init_timers(void)
1646 int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
1647 (void *)(long)smp_processor_id());
1649 init_timer_stats();
1651 BUG_ON(err == NOTIFY_BAD);
1652 register_cpu_notifier(&timers_nb);
1653 open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
1657 * msleep - sleep safely even with waitqueue interruptions
1658 * @msecs: Time in milliseconds to sleep for
1660 void msleep(unsigned int msecs)
1662 unsigned long timeout = msecs_to_jiffies(msecs) + 1;
1664 while (timeout)
1665 timeout = schedule_timeout_uninterruptible(timeout);
1668 EXPORT_SYMBOL(msleep);
1671 * msleep_interruptible - sleep waiting for signals
1672 * @msecs: Time in milliseconds to sleep for
1674 unsigned long msleep_interruptible(unsigned int msecs)
1676 unsigned long timeout = msecs_to_jiffies(msecs) + 1;
1678 while (timeout && !signal_pending(current))
1679 timeout = schedule_timeout_interruptible(timeout);
1680 return jiffies_to_msecs(timeout);
1683 EXPORT_SYMBOL(msleep_interruptible);