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/export.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/irq_work.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
);
333 static void internal_add_timer(struct tvec_base
*base
, struct timer_list
*timer
)
335 unsigned long expires
= timer
->expires
;
336 unsigned long idx
= expires
- base
->timer_jiffies
;
337 struct list_head
*vec
;
339 if (idx
< TVR_SIZE
) {
340 int i
= expires
& TVR_MASK
;
341 vec
= base
->tv1
.vec
+ i
;
342 } else if (idx
< 1 << (TVR_BITS
+ TVN_BITS
)) {
343 int i
= (expires
>> TVR_BITS
) & TVN_MASK
;
344 vec
= base
->tv2
.vec
+ i
;
345 } else if (idx
< 1 << (TVR_BITS
+ 2 * TVN_BITS
)) {
346 int i
= (expires
>> (TVR_BITS
+ TVN_BITS
)) & TVN_MASK
;
347 vec
= base
->tv3
.vec
+ i
;
348 } else if (idx
< 1 << (TVR_BITS
+ 3 * TVN_BITS
)) {
349 int i
= (expires
>> (TVR_BITS
+ 2 * TVN_BITS
)) & TVN_MASK
;
350 vec
= base
->tv4
.vec
+ i
;
351 } else if ((signed long) idx
< 0) {
353 * Can happen if you add a timer with expires == jiffies,
354 * or you set a timer to go off in the past
356 vec
= base
->tv1
.vec
+ (base
->timer_jiffies
& TVR_MASK
);
359 /* If the timeout is larger than 0xffffffff on 64-bit
360 * architectures then we use the maximum timeout:
362 if (idx
> 0xffffffffUL
) {
364 expires
= idx
+ base
->timer_jiffies
;
366 i
= (expires
>> (TVR_BITS
+ 3 * TVN_BITS
)) & TVN_MASK
;
367 vec
= base
->tv5
.vec
+ i
;
372 list_add_tail(&timer
->entry
, vec
);
375 #ifdef CONFIG_TIMER_STATS
376 void __timer_stats_timer_set_start_info(struct timer_list
*timer
, void *addr
)
378 if (timer
->start_site
)
381 timer
->start_site
= addr
;
382 memcpy(timer
->start_comm
, current
->comm
, TASK_COMM_LEN
);
383 timer
->start_pid
= current
->pid
;
386 static void timer_stats_account_timer(struct timer_list
*timer
)
388 unsigned int flag
= 0;
390 if (likely(!timer
->start_site
))
392 if (unlikely(tbase_get_deferrable(timer
->base
)))
393 flag
|= TIMER_STATS_FLAG_DEFERRABLE
;
395 timer_stats_update_stats(timer
, timer
->start_pid
, timer
->start_site
,
396 timer
->function
, timer
->start_comm
, flag
);
400 static void timer_stats_account_timer(struct timer_list
*timer
) {}
403 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
405 static struct debug_obj_descr timer_debug_descr
;
407 static void *timer_debug_hint(void *addr
)
409 return ((struct timer_list
*) addr
)->function
;
413 * fixup_init is called when:
414 * - an active object is initialized
416 static int timer_fixup_init(void *addr
, enum debug_obj_state state
)
418 struct timer_list
*timer
= addr
;
421 case ODEBUG_STATE_ACTIVE
:
422 del_timer_sync(timer
);
423 debug_object_init(timer
, &timer_debug_descr
);
430 /* Stub timer callback for improperly used timers. */
431 static void stub_timer(unsigned long data
)
437 * fixup_activate is called when:
438 * - an active object is activated
439 * - an unknown object is activated (might be a statically initialized object)
441 static int timer_fixup_activate(void *addr
, enum debug_obj_state state
)
443 struct timer_list
*timer
= addr
;
447 case ODEBUG_STATE_NOTAVAILABLE
:
449 * This is not really a fixup. The timer was
450 * statically initialized. We just make sure that it
451 * is tracked in the object tracker.
453 if (timer
->entry
.next
== NULL
&&
454 timer
->entry
.prev
== TIMER_ENTRY_STATIC
) {
455 debug_object_init(timer
, &timer_debug_descr
);
456 debug_object_activate(timer
, &timer_debug_descr
);
459 setup_timer(timer
, stub_timer
, 0);
464 case ODEBUG_STATE_ACTIVE
:
473 * fixup_free is called when:
474 * - an active object is freed
476 static int timer_fixup_free(void *addr
, enum debug_obj_state state
)
478 struct timer_list
*timer
= addr
;
481 case ODEBUG_STATE_ACTIVE
:
482 del_timer_sync(timer
);
483 debug_object_free(timer
, &timer_debug_descr
);
491 * fixup_assert_init is called when:
492 * - an untracked/uninit-ed object is found
494 static int timer_fixup_assert_init(void *addr
, enum debug_obj_state state
)
496 struct timer_list
*timer
= addr
;
499 case ODEBUG_STATE_NOTAVAILABLE
:
500 if (timer
->entry
.prev
== TIMER_ENTRY_STATIC
) {
502 * This is not really a fixup. The timer was
503 * statically initialized. We just make sure that it
504 * is tracked in the object tracker.
506 debug_object_init(timer
, &timer_debug_descr
);
509 setup_timer(timer
, stub_timer
, 0);
517 static struct debug_obj_descr timer_debug_descr
= {
518 .name
= "timer_list",
519 .debug_hint
= timer_debug_hint
,
520 .fixup_init
= timer_fixup_init
,
521 .fixup_activate
= timer_fixup_activate
,
522 .fixup_free
= timer_fixup_free
,
523 .fixup_assert_init
= timer_fixup_assert_init
,
526 static inline void debug_timer_init(struct timer_list
*timer
)
528 debug_object_init(timer
, &timer_debug_descr
);
531 static inline void debug_timer_activate(struct timer_list
*timer
)
533 debug_object_activate(timer
, &timer_debug_descr
);
536 static inline void debug_timer_deactivate(struct timer_list
*timer
)
538 debug_object_deactivate(timer
, &timer_debug_descr
);
541 static inline void debug_timer_free(struct timer_list
*timer
)
543 debug_object_free(timer
, &timer_debug_descr
);
546 static inline void debug_timer_assert_init(struct timer_list
*timer
)
548 debug_object_assert_init(timer
, &timer_debug_descr
);
551 static void __init_timer(struct timer_list
*timer
,
553 struct lock_class_key
*key
);
555 void init_timer_on_stack_key(struct timer_list
*timer
,
557 struct lock_class_key
*key
)
559 debug_object_init_on_stack(timer
, &timer_debug_descr
);
560 __init_timer(timer
, name
, key
);
562 EXPORT_SYMBOL_GPL(init_timer_on_stack_key
);
564 void destroy_timer_on_stack(struct timer_list
*timer
)
566 debug_object_free(timer
, &timer_debug_descr
);
568 EXPORT_SYMBOL_GPL(destroy_timer_on_stack
);
571 static inline void debug_timer_init(struct timer_list
*timer
) { }
572 static inline void debug_timer_activate(struct timer_list
*timer
) { }
573 static inline void debug_timer_deactivate(struct timer_list
*timer
) { }
574 static inline void debug_timer_assert_init(struct timer_list
*timer
) { }
577 static inline void debug_init(struct timer_list
*timer
)
579 debug_timer_init(timer
);
580 trace_timer_init(timer
);
584 debug_activate(struct timer_list
*timer
, unsigned long expires
)
586 debug_timer_activate(timer
);
587 trace_timer_start(timer
, expires
);
590 static inline void debug_deactivate(struct timer_list
*timer
)
592 debug_timer_deactivate(timer
);
593 trace_timer_cancel(timer
);
596 static inline void debug_assert_init(struct timer_list
*timer
)
598 debug_timer_assert_init(timer
);
601 static void __init_timer(struct timer_list
*timer
,
603 struct lock_class_key
*key
)
605 timer
->entry
.next
= NULL
;
606 timer
->base
= __raw_get_cpu_var(tvec_bases
);
608 #ifdef CONFIG_TIMER_STATS
609 timer
->start_site
= NULL
;
610 timer
->start_pid
= -1;
611 memset(timer
->start_comm
, 0, TASK_COMM_LEN
);
613 lockdep_init_map(&timer
->lockdep_map
, name
, key
, 0);
616 void setup_deferrable_timer_on_stack_key(struct timer_list
*timer
,
618 struct lock_class_key
*key
,
619 void (*function
)(unsigned long),
622 timer
->function
= function
;
624 init_timer_on_stack_key(timer
, name
, key
);
625 timer_set_deferrable(timer
);
627 EXPORT_SYMBOL_GPL(setup_deferrable_timer_on_stack_key
);
630 * init_timer_key - initialize a timer
631 * @timer: the timer to be initialized
632 * @name: name of the timer
633 * @key: lockdep class key of the fake lock used for tracking timer
634 * sync lock dependencies
636 * init_timer_key() must be done to a timer prior calling *any* of the
637 * other timer functions.
639 void init_timer_key(struct timer_list
*timer
,
641 struct lock_class_key
*key
)
644 __init_timer(timer
, name
, key
);
646 EXPORT_SYMBOL(init_timer_key
);
648 void init_timer_deferrable_key(struct timer_list
*timer
,
650 struct lock_class_key
*key
)
652 init_timer_key(timer
, name
, key
);
653 timer_set_deferrable(timer
);
655 EXPORT_SYMBOL(init_timer_deferrable_key
);
657 static inline void detach_timer(struct timer_list
*timer
,
660 struct list_head
*entry
= &timer
->entry
;
662 debug_deactivate(timer
);
664 __list_del(entry
->prev
, entry
->next
);
667 entry
->prev
= LIST_POISON2
;
671 * We are using hashed locking: holding per_cpu(tvec_bases).lock
672 * means that all timers which are tied to this base via timer->base are
673 * locked, and the base itself is locked too.
675 * So __run_timers/migrate_timers can safely modify all timers which could
676 * be found on ->tvX lists.
678 * When the timer's base is locked, and the timer removed from list, it is
679 * possible to set timer->base = NULL and drop the lock: the timer remains
682 static struct tvec_base
*lock_timer_base(struct timer_list
*timer
,
683 unsigned long *flags
)
684 __acquires(timer
->base
->lock
)
686 struct tvec_base
*base
;
689 struct tvec_base
*prelock_base
= timer
->base
;
690 base
= tbase_get_base(prelock_base
);
691 if (likely(base
!= NULL
)) {
692 spin_lock_irqsave(&base
->lock
, *flags
);
693 if (likely(prelock_base
== timer
->base
))
695 /* The timer has migrated to another CPU */
696 spin_unlock_irqrestore(&base
->lock
, *flags
);
703 __mod_timer(struct timer_list
*timer
, unsigned long expires
,
704 bool pending_only
, int pinned
)
706 struct tvec_base
*base
, *new_base
;
710 timer_stats_timer_set_start_info(timer
);
711 BUG_ON(!timer
->function
);
713 base
= lock_timer_base(timer
, &flags
);
715 if (timer_pending(timer
)) {
716 detach_timer(timer
, 0);
717 if (timer
->expires
== base
->next_timer
&&
718 !tbase_get_deferrable(timer
->base
))
719 base
->next_timer
= base
->timer_jiffies
;
726 debug_activate(timer
, expires
);
728 cpu
= smp_processor_id();
730 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
731 if (!pinned
&& get_sysctl_timer_migration() && idle_cpu(cpu
))
732 cpu
= get_nohz_timer_target();
734 new_base
= per_cpu(tvec_bases
, cpu
);
736 if (base
!= new_base
) {
738 * We are trying to schedule the timer on the local CPU.
739 * However we can't change timer's base while it is running,
740 * otherwise del_timer_sync() can't detect that the timer's
741 * handler yet has not finished. This also guarantees that
742 * the timer is serialized wrt itself.
744 if (likely(base
->running_timer
!= timer
)) {
745 /* See the comment in lock_timer_base() */
746 timer_set_base(timer
, NULL
);
747 spin_unlock(&base
->lock
);
749 spin_lock(&base
->lock
);
750 timer_set_base(timer
, base
);
754 timer
->expires
= expires
;
755 if (time_before(timer
->expires
, base
->next_timer
) &&
756 !tbase_get_deferrable(timer
->base
))
757 base
->next_timer
= timer
->expires
;
758 internal_add_timer(base
, timer
);
761 spin_unlock_irqrestore(&base
->lock
, flags
);
767 * mod_timer_pending - modify a pending timer's timeout
768 * @timer: the pending timer to be modified
769 * @expires: new timeout in jiffies
771 * mod_timer_pending() is the same for pending timers as mod_timer(),
772 * but will not re-activate and modify already deleted timers.
774 * It is useful for unserialized use of timers.
776 int mod_timer_pending(struct timer_list
*timer
, unsigned long expires
)
778 return __mod_timer(timer
, expires
, true, TIMER_NOT_PINNED
);
780 EXPORT_SYMBOL(mod_timer_pending
);
783 * Decide where to put the timer while taking the slack into account
786 * 1) calculate the maximum (absolute) time
787 * 2) calculate the highest bit where the expires and new max are different
788 * 3) use this bit to make a mask
789 * 4) use the bitmask to round down the maximum time, so that all last
793 unsigned long apply_slack(struct timer_list
*timer
, unsigned long expires
)
795 unsigned long expires_limit
, mask
;
798 if (timer
->slack
>= 0) {
799 expires_limit
= expires
+ timer
->slack
;
801 long delta
= expires
- jiffies
;
806 expires_limit
= expires
+ delta
/ 256;
808 mask
= expires
^ expires_limit
;
812 bit
= find_last_bit(&mask
, BITS_PER_LONG
);
814 mask
= (1 << bit
) - 1;
816 expires_limit
= expires_limit
& ~(mask
);
818 return expires_limit
;
822 * mod_timer - modify a timer's timeout
823 * @timer: the timer to be modified
824 * @expires: new timeout in jiffies
826 * mod_timer() is a more efficient way to update the expire field of an
827 * active timer (if the timer is inactive it will be activated)
829 * mod_timer(timer, expires) is equivalent to:
831 * del_timer(timer); timer->expires = expires; add_timer(timer);
833 * Note that if there are multiple unserialized concurrent users of the
834 * same timer, then mod_timer() is the only safe way to modify the timeout,
835 * since add_timer() cannot modify an already running timer.
837 * The function returns whether it has modified a pending timer or not.
838 * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
839 * active timer returns 1.)
841 int mod_timer(struct timer_list
*timer
, unsigned long expires
)
843 expires
= apply_slack(timer
, expires
);
846 * This is a common optimization triggered by the
847 * networking code - if the timer is re-modified
848 * to be the same thing then just return:
850 if (timer_pending(timer
) && timer
->expires
== expires
)
853 return __mod_timer(timer
, expires
, false, TIMER_NOT_PINNED
);
855 EXPORT_SYMBOL(mod_timer
);
858 * mod_timer_pinned - modify a timer's timeout
859 * @timer: the timer to be modified
860 * @expires: new timeout in jiffies
862 * mod_timer_pinned() is a way to update the expire field of an
863 * active timer (if the timer is inactive it will be activated)
864 * and not allow the timer to be migrated to a different CPU.
866 * mod_timer_pinned(timer, expires) is equivalent to:
868 * del_timer(timer); timer->expires = expires; add_timer(timer);
870 int mod_timer_pinned(struct timer_list
*timer
, unsigned long expires
)
872 if (timer
->expires
== expires
&& timer_pending(timer
))
875 return __mod_timer(timer
, expires
, false, TIMER_PINNED
);
877 EXPORT_SYMBOL(mod_timer_pinned
);
880 * add_timer - start a timer
881 * @timer: the timer to be added
883 * The kernel will do a ->function(->data) callback from the
884 * timer interrupt at the ->expires point in the future. The
885 * current time is 'jiffies'.
887 * The timer's ->expires, ->function (and if the handler uses it, ->data)
888 * fields must be set prior calling this function.
890 * Timers with an ->expires field in the past will be executed in the next
893 void add_timer(struct timer_list
*timer
)
895 BUG_ON(timer_pending(timer
));
896 mod_timer(timer
, timer
->expires
);
898 EXPORT_SYMBOL(add_timer
);
901 * add_timer_on - start a timer on a particular CPU
902 * @timer: the timer to be added
903 * @cpu: the CPU to start it on
905 * This is not very scalable on SMP. Double adds are not possible.
907 void add_timer_on(struct timer_list
*timer
, int cpu
)
909 struct tvec_base
*base
= per_cpu(tvec_bases
, cpu
);
912 timer_stats_timer_set_start_info(timer
);
913 BUG_ON(timer_pending(timer
) || !timer
->function
);
914 spin_lock_irqsave(&base
->lock
, flags
);
915 timer_set_base(timer
, base
);
916 debug_activate(timer
, timer
->expires
);
917 if (time_before(timer
->expires
, base
->next_timer
) &&
918 !tbase_get_deferrable(timer
->base
))
919 base
->next_timer
= timer
->expires
;
920 internal_add_timer(base
, timer
);
922 * Check whether the other CPU is idle and needs to be
923 * triggered to reevaluate the timer wheel when nohz is
924 * active. We are protected against the other CPU fiddling
925 * with the timer by holding the timer base lock. This also
926 * makes sure that a CPU on the way to idle can not evaluate
929 wake_up_idle_cpu(cpu
);
930 spin_unlock_irqrestore(&base
->lock
, flags
);
932 EXPORT_SYMBOL_GPL(add_timer_on
);
935 * del_timer - deactive a timer.
936 * @timer: the timer to be deactivated
938 * del_timer() deactivates a timer - this works on both active and inactive
941 * The function returns whether it has deactivated a pending timer or not.
942 * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
943 * active timer returns 1.)
945 int del_timer(struct timer_list
*timer
)
947 struct tvec_base
*base
;
951 debug_assert_init(timer
);
953 timer_stats_timer_clear_start_info(timer
);
954 if (timer_pending(timer
)) {
955 base
= lock_timer_base(timer
, &flags
);
956 if (timer_pending(timer
)) {
957 detach_timer(timer
, 1);
958 if (timer
->expires
== base
->next_timer
&&
959 !tbase_get_deferrable(timer
->base
))
960 base
->next_timer
= base
->timer_jiffies
;
963 spin_unlock_irqrestore(&base
->lock
, flags
);
968 EXPORT_SYMBOL(del_timer
);
971 * try_to_del_timer_sync - Try to deactivate a timer
972 * @timer: timer do del
974 * This function tries to deactivate a timer. Upon successful (ret >= 0)
975 * exit the timer is not queued and the handler is not running on any CPU.
977 int try_to_del_timer_sync(struct timer_list
*timer
)
979 struct tvec_base
*base
;
983 debug_assert_init(timer
);
985 base
= lock_timer_base(timer
, &flags
);
987 if (base
->running_timer
== timer
)
990 timer_stats_timer_clear_start_info(timer
);
992 if (timer_pending(timer
)) {
993 detach_timer(timer
, 1);
994 if (timer
->expires
== base
->next_timer
&&
995 !tbase_get_deferrable(timer
->base
))
996 base
->next_timer
= base
->timer_jiffies
;
1000 spin_unlock_irqrestore(&base
->lock
, flags
);
1004 EXPORT_SYMBOL(try_to_del_timer_sync
);
1008 * del_timer_sync - deactivate a timer and wait for the handler to finish.
1009 * @timer: the timer to be deactivated
1011 * This function only differs from del_timer() on SMP: besides deactivating
1012 * the timer it also makes sure the handler has finished executing on other
1015 * Synchronization rules: Callers must prevent restarting of the timer,
1016 * otherwise this function is meaningless. It must not be called from
1017 * interrupt contexts. The caller must not hold locks which would prevent
1018 * completion of the timer's handler. The timer's handler must not call
1019 * add_timer_on(). Upon exit the timer is not queued and the handler is
1020 * not running on any CPU.
1022 * Note: You must not hold locks that are held in interrupt context
1023 * while calling this function. Even if the lock has nothing to do
1024 * with the timer in question. Here's why:
1030 * base->running_timer = mytimer;
1031 * spin_lock_irq(somelock);
1033 * spin_lock(somelock);
1034 * del_timer_sync(mytimer);
1035 * while (base->running_timer == mytimer);
1037 * Now del_timer_sync() will never return and never release somelock.
1038 * The interrupt on the other CPU is waiting to grab somelock but
1039 * it has interrupted the softirq that CPU0 is waiting to finish.
1041 * The function returns whether it has deactivated a pending timer or not.
1043 int del_timer_sync(struct timer_list
*timer
)
1045 #ifdef CONFIG_LOCKDEP
1046 unsigned long flags
;
1049 * If lockdep gives a backtrace here, please reference
1050 * the synchronization rules above.
1052 local_irq_save(flags
);
1053 lock_map_acquire(&timer
->lockdep_map
);
1054 lock_map_release(&timer
->lockdep_map
);
1055 local_irq_restore(flags
);
1058 * don't use it in hardirq context, because it
1059 * could lead to deadlock.
1063 int ret
= try_to_del_timer_sync(timer
);
1069 EXPORT_SYMBOL(del_timer_sync
);
1072 static int cascade(struct tvec_base
*base
, struct tvec
*tv
, int index
)
1074 /* cascade all the timers from tv up one level */
1075 struct timer_list
*timer
, *tmp
;
1076 struct list_head tv_list
;
1078 list_replace_init(tv
->vec
+ index
, &tv_list
);
1081 * We are removing _all_ timers from the list, so we
1082 * don't have to detach them individually.
1084 list_for_each_entry_safe(timer
, tmp
, &tv_list
, entry
) {
1085 BUG_ON(tbase_get_base(timer
->base
) != base
);
1086 internal_add_timer(base
, timer
);
1092 static void call_timer_fn(struct timer_list
*timer
, void (*fn
)(unsigned long),
1095 int preempt_count
= preempt_count();
1097 #ifdef CONFIG_LOCKDEP
1099 * It is permissible to free the timer from inside the
1100 * function that is called from it, this we need to take into
1101 * account for lockdep too. To avoid bogus "held lock freed"
1102 * warnings as well as problems when looking into
1103 * timer->lockdep_map, make a copy and use that here.
1105 struct lockdep_map lockdep_map
;
1107 lockdep_copy_map(&lockdep_map
, &timer
->lockdep_map
);
1110 * Couple the lock chain with the lock chain at
1111 * del_timer_sync() by acquiring the lock_map around the fn()
1112 * call here and in del_timer_sync().
1114 lock_map_acquire(&lockdep_map
);
1116 trace_timer_expire_entry(timer
);
1118 trace_timer_expire_exit(timer
);
1120 lock_map_release(&lockdep_map
);
1122 if (preempt_count
!= preempt_count()) {
1123 WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n",
1124 fn
, preempt_count
, preempt_count());
1126 * Restore the preempt count. That gives us a decent
1127 * chance to survive and extract information. If the
1128 * callback kept a lock held, bad luck, but not worse
1129 * than the BUG() we had.
1131 preempt_count() = preempt_count
;
1135 #define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
1138 * __run_timers - run all expired timers (if any) on this CPU.
1139 * @base: the timer vector to be processed.
1141 * This function cascades all vectors and executes all expired timer
1144 static inline void __run_timers(struct tvec_base
*base
)
1146 struct timer_list
*timer
;
1148 spin_lock_irq(&base
->lock
);
1149 while (time_after_eq(jiffies
, base
->timer_jiffies
)) {
1150 struct list_head work_list
;
1151 struct list_head
*head
= &work_list
;
1152 int index
= base
->timer_jiffies
& TVR_MASK
;
1158 (!cascade(base
, &base
->tv2
, INDEX(0))) &&
1159 (!cascade(base
, &base
->tv3
, INDEX(1))) &&
1160 !cascade(base
, &base
->tv4
, INDEX(2)))
1161 cascade(base
, &base
->tv5
, INDEX(3));
1162 ++base
->timer_jiffies
;
1163 list_replace_init(base
->tv1
.vec
+ index
, &work_list
);
1164 while (!list_empty(head
)) {
1165 void (*fn
)(unsigned long);
1168 timer
= list_first_entry(head
, struct timer_list
,entry
);
1169 fn
= timer
->function
;
1172 timer_stats_account_timer(timer
);
1174 base
->running_timer
= timer
;
1175 detach_timer(timer
, 1);
1177 spin_unlock_irq(&base
->lock
);
1178 call_timer_fn(timer
, fn
, data
);
1179 spin_lock_irq(&base
->lock
);
1182 base
->running_timer
= NULL
;
1183 spin_unlock_irq(&base
->lock
);
1188 * Find out when the next timer event is due to happen. This
1189 * is used on S/390 to stop all activity when a CPU is idle.
1190 * This function needs to be called with interrupts disabled.
1192 static unsigned long __next_timer_interrupt(struct tvec_base
*base
)
1194 unsigned long timer_jiffies
= base
->timer_jiffies
;
1195 unsigned long expires
= timer_jiffies
+ NEXT_TIMER_MAX_DELTA
;
1196 int index
, slot
, array
, found
= 0;
1197 struct timer_list
*nte
;
1198 struct tvec
*varray
[4];
1200 /* Look for timer events in tv1. */
1201 index
= slot
= timer_jiffies
& TVR_MASK
;
1203 list_for_each_entry(nte
, base
->tv1
.vec
+ slot
, entry
) {
1204 if (tbase_get_deferrable(nte
->base
))
1208 expires
= nte
->expires
;
1209 /* Look at the cascade bucket(s)? */
1210 if (!index
|| slot
< index
)
1214 slot
= (slot
+ 1) & TVR_MASK
;
1215 } while (slot
!= index
);
1218 /* Calculate the next cascade event */
1220 timer_jiffies
+= TVR_SIZE
- index
;
1221 timer_jiffies
>>= TVR_BITS
;
1223 /* Check tv2-tv5. */
1224 varray
[0] = &base
->tv2
;
1225 varray
[1] = &base
->tv3
;
1226 varray
[2] = &base
->tv4
;
1227 varray
[3] = &base
->tv5
;
1229 for (array
= 0; array
< 4; array
++) {
1230 struct tvec
*varp
= varray
[array
];
1232 index
= slot
= timer_jiffies
& TVN_MASK
;
1234 list_for_each_entry(nte
, varp
->vec
+ slot
, entry
) {
1235 if (tbase_get_deferrable(nte
->base
))
1239 if (time_before(nte
->expires
, expires
))
1240 expires
= nte
->expires
;
1243 * Do we still search for the first timer or are
1244 * we looking up the cascade buckets ?
1247 /* Look at the cascade bucket(s)? */
1248 if (!index
|| slot
< index
)
1252 slot
= (slot
+ 1) & TVN_MASK
;
1253 } while (slot
!= index
);
1256 timer_jiffies
+= TVN_SIZE
- index
;
1257 timer_jiffies
>>= TVN_BITS
;
1263 * Check, if the next hrtimer event is before the next timer wheel
1266 static unsigned long cmp_next_hrtimer_event(unsigned long now
,
1267 unsigned long expires
)
1269 ktime_t hr_delta
= hrtimer_get_next_event();
1270 struct timespec tsdelta
;
1271 unsigned long delta
;
1273 if (hr_delta
.tv64
== KTIME_MAX
)
1277 * Expired timer available, let it expire in the next tick
1279 if (hr_delta
.tv64
<= 0)
1282 tsdelta
= ktime_to_timespec(hr_delta
);
1283 delta
= timespec_to_jiffies(&tsdelta
);
1286 * Limit the delta to the max value, which is checked in
1287 * tick_nohz_stop_sched_tick():
1289 if (delta
> NEXT_TIMER_MAX_DELTA
)
1290 delta
= NEXT_TIMER_MAX_DELTA
;
1293 * Take rounding errors in to account and make sure, that it
1294 * expires in the next tick. Otherwise we go into an endless
1295 * ping pong due to tick_nohz_stop_sched_tick() retriggering
1301 if (time_before(now
, expires
))
1307 * get_next_timer_interrupt - return the jiffy of the next pending timer
1308 * @now: current time (in jiffies)
1310 unsigned long get_next_timer_interrupt(unsigned long now
)
1312 struct tvec_base
*base
= __this_cpu_read(tvec_bases
);
1313 unsigned long expires
;
1316 * Pretend that there is no timer pending if the cpu is offline.
1317 * Possible pending timers will be migrated later to an active cpu.
1319 if (cpu_is_offline(smp_processor_id()))
1320 return now
+ NEXT_TIMER_MAX_DELTA
;
1321 spin_lock(&base
->lock
);
1322 if (time_before_eq(base
->next_timer
, base
->timer_jiffies
))
1323 base
->next_timer
= __next_timer_interrupt(base
);
1324 expires
= base
->next_timer
;
1325 spin_unlock(&base
->lock
);
1327 if (time_before_eq(expires
, now
))
1330 return cmp_next_hrtimer_event(now
, expires
);
1335 * Called from the timer interrupt handler to charge one tick to the current
1336 * process. user_tick is 1 if the tick is user time, 0 for system.
1338 void update_process_times(int user_tick
)
1340 struct task_struct
*p
= current
;
1341 int cpu
= smp_processor_id();
1343 /* Note: this timer irq context must be accounted for as well. */
1344 account_process_tick(p
, user_tick
);
1346 rcu_check_callbacks(cpu
, user_tick
);
1348 #ifdef CONFIG_IRQ_WORK
1353 run_posix_cpu_timers(p
);
1357 * This function runs timers and the timer-tq in bottom half context.
1359 static void run_timer_softirq(struct softirq_action
*h
)
1361 struct tvec_base
*base
= __this_cpu_read(tvec_bases
);
1363 hrtimer_run_pending();
1365 if (time_after_eq(jiffies
, base
->timer_jiffies
))
1370 * Called by the local, per-CPU timer interrupt on SMP.
1372 void run_local_timers(void)
1374 hrtimer_run_queues();
1375 raise_softirq(TIMER_SOFTIRQ
);
1378 #ifdef __ARCH_WANT_SYS_ALARM
1381 * For backwards compatibility? This can be done in libc so Alpha
1382 * and all newer ports shouldn't need it.
1384 SYSCALL_DEFINE1(alarm
, unsigned int, seconds
)
1386 return alarm_setitimer(seconds
);
1394 * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this
1395 * should be moved into arch/i386 instead?
1399 * sys_getpid - return the thread group id of the current process
1401 * Note, despite the name, this returns the tgid not the pid. The tgid and
1402 * the pid are identical unless CLONE_THREAD was specified on clone() in
1403 * which case the tgid is the same in all threads of the same group.
1405 * This is SMP safe as current->tgid does not change.
1407 SYSCALL_DEFINE0(getpid
)
1409 return task_tgid_vnr(current
);
1413 * Accessing ->real_parent is not SMP-safe, it could
1414 * change from under us. However, we can use a stale
1415 * value of ->real_parent under rcu_read_lock(), see
1416 * release_task()->call_rcu(delayed_put_task_struct).
1418 SYSCALL_DEFINE0(getppid
)
1423 pid
= task_tgid_vnr(rcu_dereference(current
->real_parent
));
1429 SYSCALL_DEFINE0(getuid
)
1431 /* Only we change this so SMP safe */
1432 return current_uid();
1435 SYSCALL_DEFINE0(geteuid
)
1437 /* Only we change this so SMP safe */
1438 return current_euid();
1441 SYSCALL_DEFINE0(getgid
)
1443 /* Only we change this so SMP safe */
1444 return current_gid();
1447 SYSCALL_DEFINE0(getegid
)
1449 /* Only we change this so SMP safe */
1450 return current_egid();
1455 static void process_timeout(unsigned long __data
)
1457 wake_up_process((struct task_struct
*)__data
);
1461 * schedule_timeout - sleep until timeout
1462 * @timeout: timeout value in jiffies
1464 * Make the current task sleep until @timeout jiffies have
1465 * elapsed. The routine will return immediately unless
1466 * the current task state has been set (see set_current_state()).
1468 * You can set the task state as follows -
1470 * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
1471 * pass before the routine returns. The routine will return 0
1473 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
1474 * delivered to the current task. In this case the remaining time
1475 * in jiffies will be returned, or 0 if the timer expired in time
1477 * The current task state is guaranteed to be TASK_RUNNING when this
1480 * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
1481 * the CPU away without a bound on the timeout. In this case the return
1482 * value will be %MAX_SCHEDULE_TIMEOUT.
1484 * In all cases the return value is guaranteed to be non-negative.
1486 signed long __sched
schedule_timeout(signed long timeout
)
1488 struct timer_list timer
;
1489 unsigned long expire
;
1493 case MAX_SCHEDULE_TIMEOUT
:
1495 * These two special cases are useful to be comfortable
1496 * in the caller. Nothing more. We could take
1497 * MAX_SCHEDULE_TIMEOUT from one of the negative value
1498 * but I' d like to return a valid offset (>=0) to allow
1499 * the caller to do everything it want with the retval.
1505 * Another bit of PARANOID. Note that the retval will be
1506 * 0 since no piece of kernel is supposed to do a check
1507 * for a negative retval of schedule_timeout() (since it
1508 * should never happens anyway). You just have the printk()
1509 * that will tell you if something is gone wrong and where.
1512 printk(KERN_ERR
"schedule_timeout: wrong timeout "
1513 "value %lx\n", timeout
);
1515 current
->state
= TASK_RUNNING
;
1520 expire
= timeout
+ jiffies
;
1522 setup_timer_on_stack(&timer
, process_timeout
, (unsigned long)current
);
1523 __mod_timer(&timer
, expire
, false, TIMER_NOT_PINNED
);
1525 del_singleshot_timer_sync(&timer
);
1527 /* Remove the timer from the object tracker */
1528 destroy_timer_on_stack(&timer
);
1530 timeout
= expire
- jiffies
;
1533 return timeout
< 0 ? 0 : timeout
;
1535 EXPORT_SYMBOL(schedule_timeout
);
1538 * We can use __set_current_state() here because schedule_timeout() calls
1539 * schedule() unconditionally.
1541 signed long __sched
schedule_timeout_interruptible(signed long timeout
)
1543 __set_current_state(TASK_INTERRUPTIBLE
);
1544 return schedule_timeout(timeout
);
1546 EXPORT_SYMBOL(schedule_timeout_interruptible
);
1548 signed long __sched
schedule_timeout_killable(signed long timeout
)
1550 __set_current_state(TASK_KILLABLE
);
1551 return schedule_timeout(timeout
);
1553 EXPORT_SYMBOL(schedule_timeout_killable
);
1555 signed long __sched
schedule_timeout_uninterruptible(signed long timeout
)
1557 __set_current_state(TASK_UNINTERRUPTIBLE
);
1558 return schedule_timeout(timeout
);
1560 EXPORT_SYMBOL(schedule_timeout_uninterruptible
);
1562 /* Thread ID - the internal kernel "pid" */
1563 SYSCALL_DEFINE0(gettid
)
1565 return task_pid_vnr(current
);
1569 * do_sysinfo - fill in sysinfo struct
1570 * @info: pointer to buffer to fill
1572 int do_sysinfo(struct sysinfo
*info
)
1574 unsigned long mem_total
, sav_total
;
1575 unsigned int mem_unit
, bitcount
;
1578 memset(info
, 0, sizeof(struct sysinfo
));
1581 monotonic_to_bootbased(&tp
);
1582 info
->uptime
= tp
.tv_sec
+ (tp
.tv_nsec
? 1 : 0);
1584 get_avenrun(info
->loads
, 0, SI_LOAD_SHIFT
- FSHIFT
);
1586 info
->procs
= nr_threads
;
1592 * If the sum of all the available memory (i.e. ram + swap)
1593 * is less than can be stored in a 32 bit unsigned long then
1594 * we can be binary compatible with 2.2.x kernels. If not,
1595 * well, in that case 2.2.x was broken anyways...
1597 * -Erik Andersen <andersee@debian.org>
1600 mem_total
= info
->totalram
+ info
->totalswap
;
1601 if (mem_total
< info
->totalram
|| mem_total
< info
->totalswap
)
1604 mem_unit
= info
->mem_unit
;
1605 while (mem_unit
> 1) {
1608 sav_total
= mem_total
;
1610 if (mem_total
< sav_total
)
1615 * If mem_total did not overflow, multiply all memory values by
1616 * info->mem_unit and set it to 1. This leaves things compatible
1617 * with 2.2.x, and also retains compatibility with earlier 2.4.x
1622 info
->totalram
<<= bitcount
;
1623 info
->freeram
<<= bitcount
;
1624 info
->sharedram
<<= bitcount
;
1625 info
->bufferram
<<= bitcount
;
1626 info
->totalswap
<<= bitcount
;
1627 info
->freeswap
<<= bitcount
;
1628 info
->totalhigh
<<= bitcount
;
1629 info
->freehigh
<<= bitcount
;
1635 SYSCALL_DEFINE1(sysinfo
, struct sysinfo __user
*, info
)
1641 if (copy_to_user(info
, &val
, sizeof(struct sysinfo
)))
1647 static int __cpuinit
init_timers_cpu(int cpu
)
1650 struct tvec_base
*base
;
1651 static char __cpuinitdata tvec_base_done
[NR_CPUS
];
1653 if (!tvec_base_done
[cpu
]) {
1654 static char boot_done
;
1658 * The APs use this path later in boot
1660 base
= kmalloc_node(sizeof(*base
),
1661 GFP_KERNEL
| __GFP_ZERO
,
1666 /* Make sure that tvec_base is 2 byte aligned */
1667 if (tbase_get_deferrable(base
)) {
1672 per_cpu(tvec_bases
, cpu
) = base
;
1675 * This is for the boot CPU - we use compile-time
1676 * static initialisation because per-cpu memory isn't
1677 * ready yet and because the memory allocators are not
1678 * initialised either.
1681 base
= &boot_tvec_bases
;
1683 tvec_base_done
[cpu
] = 1;
1685 base
= per_cpu(tvec_bases
, cpu
);
1688 spin_lock_init(&base
->lock
);
1690 for (j
= 0; j
< TVN_SIZE
; j
++) {
1691 INIT_LIST_HEAD(base
->tv5
.vec
+ j
);
1692 INIT_LIST_HEAD(base
->tv4
.vec
+ j
);
1693 INIT_LIST_HEAD(base
->tv3
.vec
+ j
);
1694 INIT_LIST_HEAD(base
->tv2
.vec
+ j
);
1696 for (j
= 0; j
< TVR_SIZE
; j
++)
1697 INIT_LIST_HEAD(base
->tv1
.vec
+ j
);
1699 base
->timer_jiffies
= jiffies
;
1700 base
->next_timer
= base
->timer_jiffies
;
1704 #ifdef CONFIG_HOTPLUG_CPU
1705 static void migrate_timer_list(struct tvec_base
*new_base
, struct list_head
*head
)
1707 struct timer_list
*timer
;
1709 while (!list_empty(head
)) {
1710 timer
= list_first_entry(head
, struct timer_list
, entry
);
1711 detach_timer(timer
, 0);
1712 timer_set_base(timer
, new_base
);
1713 if (time_before(timer
->expires
, new_base
->next_timer
) &&
1714 !tbase_get_deferrable(timer
->base
))
1715 new_base
->next_timer
= timer
->expires
;
1716 internal_add_timer(new_base
, timer
);
1720 static void __cpuinit
migrate_timers(int cpu
)
1722 struct tvec_base
*old_base
;
1723 struct tvec_base
*new_base
;
1726 BUG_ON(cpu_online(cpu
));
1727 old_base
= per_cpu(tvec_bases
, cpu
);
1728 new_base
= get_cpu_var(tvec_bases
);
1730 * The caller is globally serialized and nobody else
1731 * takes two locks at once, deadlock is not possible.
1733 spin_lock_irq(&new_base
->lock
);
1734 spin_lock_nested(&old_base
->lock
, SINGLE_DEPTH_NESTING
);
1736 BUG_ON(old_base
->running_timer
);
1738 for (i
= 0; i
< TVR_SIZE
; i
++)
1739 migrate_timer_list(new_base
, old_base
->tv1
.vec
+ i
);
1740 for (i
= 0; i
< TVN_SIZE
; i
++) {
1741 migrate_timer_list(new_base
, old_base
->tv2
.vec
+ i
);
1742 migrate_timer_list(new_base
, old_base
->tv3
.vec
+ i
);
1743 migrate_timer_list(new_base
, old_base
->tv4
.vec
+ i
);
1744 migrate_timer_list(new_base
, old_base
->tv5
.vec
+ i
);
1747 spin_unlock(&old_base
->lock
);
1748 spin_unlock_irq(&new_base
->lock
);
1749 put_cpu_var(tvec_bases
);
1751 #endif /* CONFIG_HOTPLUG_CPU */
1753 static int __cpuinit
timer_cpu_notify(struct notifier_block
*self
,
1754 unsigned long action
, void *hcpu
)
1756 long cpu
= (long)hcpu
;
1760 case CPU_UP_PREPARE
:
1761 case CPU_UP_PREPARE_FROZEN
:
1762 err
= init_timers_cpu(cpu
);
1764 return notifier_from_errno(err
);
1766 #ifdef CONFIG_HOTPLUG_CPU
1768 case CPU_DEAD_FROZEN
:
1769 migrate_timers(cpu
);
1778 static struct notifier_block __cpuinitdata timers_nb
= {
1779 .notifier_call
= timer_cpu_notify
,
1783 void __init
init_timers(void)
1785 int err
= timer_cpu_notify(&timers_nb
, (unsigned long)CPU_UP_PREPARE
,
1786 (void *)(long)smp_processor_id());
1790 BUG_ON(err
!= NOTIFY_OK
);
1791 register_cpu_notifier(&timers_nb
);
1792 open_softirq(TIMER_SOFTIRQ
, run_timer_softirq
);
1796 * msleep - sleep safely even with waitqueue interruptions
1797 * @msecs: Time in milliseconds to sleep for
1799 void msleep(unsigned int msecs
)
1801 unsigned long timeout
= msecs_to_jiffies(msecs
) + 1;
1804 timeout
= schedule_timeout_uninterruptible(timeout
);
1807 EXPORT_SYMBOL(msleep
);
1810 * msleep_interruptible - sleep waiting for signals
1811 * @msecs: Time in milliseconds to sleep for
1813 unsigned long msleep_interruptible(unsigned int msecs
)
1815 unsigned long timeout
= msecs_to_jiffies(msecs
) + 1;
1817 while (timeout
&& !signal_pending(current
))
1818 timeout
= schedule_timeout_interruptible(timeout
);
1819 return jiffies_to_msecs(timeout
);
1822 EXPORT_SYMBOL(msleep_interruptible
);
1824 static int __sched
do_usleep_range(unsigned long min
, unsigned long max
)
1827 unsigned long delta
;
1829 kmin
= ktime_set(0, min
* NSEC_PER_USEC
);
1830 delta
= (max
- min
) * NSEC_PER_USEC
;
1831 return schedule_hrtimeout_range(&kmin
, delta
, HRTIMER_MODE_REL
);
1835 * usleep_range - Drop in replacement for udelay where wakeup is flexible
1836 * @min: Minimum time in usecs to sleep
1837 * @max: Maximum time in usecs to sleep
1839 void usleep_range(unsigned long min
, unsigned long max
)
1841 __set_current_state(TASK_UNINTERRUPTIBLE
);
1842 do_usleep_range(min
, max
);
1844 EXPORT_SYMBOL(usleep_range
);