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-rw-r--r--kernel/hrtimer.c568
1 files changed, 520 insertions, 48 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index e04ef38ea3be..62aad8e1a383 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -3,7 +3,7 @@
3 * 3 *
4 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> 4 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
5 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar 5 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
6 * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner <tglx@timesys.com> 6 * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner
7 * 7 *
8 * High-resolution kernel timers 8 * High-resolution kernel timers
9 * 9 *
@@ -32,13 +32,17 @@
32 */ 32 */
33 33
34#include <linux/cpu.h> 34#include <linux/cpu.h>
35#include <linux/irq.h>
35#include <linux/module.h> 36#include <linux/module.h>
36#include <linux/percpu.h> 37#include <linux/percpu.h>
37#include <linux/hrtimer.h> 38#include <linux/hrtimer.h>
38#include <linux/notifier.h> 39#include <linux/notifier.h>
39#include <linux/syscalls.h> 40#include <linux/syscalls.h>
41#include <linux/kallsyms.h>
40#include <linux/interrupt.h> 42#include <linux/interrupt.h>
41#include <linux/tick.h> 43#include <linux/tick.h>
44#include <linux/seq_file.h>
45#include <linux/err.h>
42 46
43#include <asm/uaccess.h> 47#include <asm/uaccess.h>
44 48
@@ -81,7 +85,7 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
81 * This ensures that we capture erroneous accesses to these clock ids 85 * This ensures that we capture erroneous accesses to these clock ids
82 * rather than moving them into the range of valid clock id's. 86 * rather than moving them into the range of valid clock id's.
83 */ 87 */
84static DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = 88DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
85{ 89{
86 90
87 .clock_base = 91 .clock_base =
@@ -89,12 +93,12 @@ static DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
89 { 93 {
90 .index = CLOCK_REALTIME, 94 .index = CLOCK_REALTIME,
91 .get_time = &ktime_get_real, 95 .get_time = &ktime_get_real,
92 .resolution = KTIME_REALTIME_RES, 96 .resolution = KTIME_LOW_RES,
93 }, 97 },
94 { 98 {
95 .index = CLOCK_MONOTONIC, 99 .index = CLOCK_MONOTONIC,
96 .get_time = &ktime_get, 100 .get_time = &ktime_get,
97 .resolution = KTIME_MONOTONIC_RES, 101 .resolution = KTIME_LOW_RES,
98 }, 102 },
99 } 103 }
100}; 104};
@@ -151,14 +155,6 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
151} 155}
152 156
153/* 157/*
154 * Helper function to check, whether the timer is on one of the queues
155 */
156static inline int hrtimer_is_queued(struct hrtimer *timer)
157{
158 return timer->state & HRTIMER_STATE_ENQUEUED;
159}
160
161/*
162 * Helper function to check, whether the timer is running the callback 158 * Helper function to check, whether the timer is running the callback
163 * function 159 * function
164 */ 160 */
@@ -226,7 +222,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base)
226 * completed. There is no conflict as we hold the lock until 222 * completed. There is no conflict as we hold the lock until
227 * the timer is enqueued. 223 * the timer is enqueued.
228 */ 224 */
229 if (unlikely(timer->state & HRTIMER_STATE_CALLBACK)) 225 if (unlikely(hrtimer_callback_running(timer)))
230 return base; 226 return base;
231 227
232 /* See the comment in lock_timer_base() */ 228 /* See the comment in lock_timer_base() */
@@ -250,7 +246,7 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
250 return base; 246 return base;
251} 247}
252 248
253#define switch_hrtimer_base(t, b) (b) 249# define switch_hrtimer_base(t, b) (b)
254 250
255#endif /* !CONFIG_SMP */ 251#endif /* !CONFIG_SMP */
256 252
@@ -281,9 +277,6 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
281 277
282 return ktime_add(kt, tmp); 278 return ktime_add(kt, tmp);
283} 279}
284
285#else /* CONFIG_KTIME_SCALAR */
286
287# endif /* !CONFIG_KTIME_SCALAR */ 280# endif /* !CONFIG_KTIME_SCALAR */
288 281
289/* 282/*
@@ -308,6 +301,290 @@ unsigned long ktime_divns(const ktime_t kt, s64 div)
308} 301}
309#endif /* BITS_PER_LONG >= 64 */ 302#endif /* BITS_PER_LONG >= 64 */
310 303
304/* High resolution timer related functions */
305#ifdef CONFIG_HIGH_RES_TIMERS
306
307/*
308 * High resolution timer enabled ?
309 */
310static int hrtimer_hres_enabled __read_mostly = 1;
311
312/*
313 * Enable / Disable high resolution mode
314 */
315static int __init setup_hrtimer_hres(char *str)
316{
317 if (!strcmp(str, "off"))
318 hrtimer_hres_enabled = 0;
319 else if (!strcmp(str, "on"))
320 hrtimer_hres_enabled = 1;
321 else
322 return 0;
323 return 1;
324}
325
326__setup("highres=", setup_hrtimer_hres);
327
328/*
329 * hrtimer_high_res_enabled - query, if the highres mode is enabled
330 */
331static inline int hrtimer_is_hres_enabled(void)
332{
333 return hrtimer_hres_enabled;
334}
335
336/*
337 * Is the high resolution mode active ?
338 */
339static inline int hrtimer_hres_active(void)
340{
341 return __get_cpu_var(hrtimer_bases).hres_active;
342}
343
344/*
345 * Reprogram the event source with checking both queues for the
346 * next event
347 * Called with interrupts disabled and base->lock held
348 */
349static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
350{
351 int i;
352 struct hrtimer_clock_base *base = cpu_base->clock_base;
353 ktime_t expires;
354
355 cpu_base->expires_next.tv64 = KTIME_MAX;
356
357 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
358 struct hrtimer *timer;
359
360 if (!base->first)
361 continue;
362 timer = rb_entry(base->first, struct hrtimer, node);
363 expires = ktime_sub(timer->expires, base->offset);
364 if (expires.tv64 < cpu_base->expires_next.tv64)
365 cpu_base->expires_next = expires;
366 }
367
368 if (cpu_base->expires_next.tv64 != KTIME_MAX)
369 tick_program_event(cpu_base->expires_next, 1);
370}
371
372/*
373 * Shared reprogramming for clock_realtime and clock_monotonic
374 *
375 * When a timer is enqueued and expires earlier than the already enqueued
376 * timers, we have to check, whether it expires earlier than the timer for
377 * which the clock event device was armed.
378 *
379 * Called with interrupts disabled and base->cpu_base.lock held
380 */
381static int hrtimer_reprogram(struct hrtimer *timer,
382 struct hrtimer_clock_base *base)
383{
384 ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
385 ktime_t expires = ktime_sub(timer->expires, base->offset);
386 int res;
387
388 /*
389 * When the callback is running, we do not reprogram the clock event
390 * device. The timer callback is either running on a different CPU or
391 * the callback is executed in the hrtimer_interupt context. The
392 * reprogramming is handled either by the softirq, which called the
393 * callback or at the end of the hrtimer_interrupt.
394 */
395 if (hrtimer_callback_running(timer))
396 return 0;
397
398 if (expires.tv64 >= expires_next->tv64)
399 return 0;
400
401 /*
402 * Clockevents returns -ETIME, when the event was in the past.
403 */
404 res = tick_program_event(expires, 0);
405 if (!IS_ERR_VALUE(res))
406 *expires_next = expires;
407 return res;
408}
409
410
411/*
412 * Retrigger next event is called after clock was set
413 *
414 * Called with interrupts disabled via on_each_cpu()
415 */
416static void retrigger_next_event(void *arg)
417{
418 struct hrtimer_cpu_base *base;
419 struct timespec realtime_offset;
420 unsigned long seq;
421
422 if (!hrtimer_hres_active())
423 return;
424
425 do {
426 seq = read_seqbegin(&xtime_lock);
427 set_normalized_timespec(&realtime_offset,
428 -wall_to_monotonic.tv_sec,
429 -wall_to_monotonic.tv_nsec);
430 } while (read_seqretry(&xtime_lock, seq));
431
432 base = &__get_cpu_var(hrtimer_bases);
433
434 /* Adjust CLOCK_REALTIME offset */
435 spin_lock(&base->lock);
436 base->clock_base[CLOCK_REALTIME].offset =
437 timespec_to_ktime(realtime_offset);
438
439 hrtimer_force_reprogram(base);
440 spin_unlock(&base->lock);
441}
442
443/*
444 * Clock realtime was set
445 *
446 * Change the offset of the realtime clock vs. the monotonic
447 * clock.
448 *
449 * We might have to reprogram the high resolution timer interrupt. On
450 * SMP we call the architecture specific code to retrigger _all_ high
451 * resolution timer interrupts. On UP we just disable interrupts and
452 * call the high resolution interrupt code.
453 */
454void clock_was_set(void)
455{
456 /* Retrigger the CPU local events everywhere */
457 on_each_cpu(retrigger_next_event, NULL, 0, 1);
458}
459
460/*
461 * Check, whether the timer is on the callback pending list
462 */
463static inline int hrtimer_cb_pending(const struct hrtimer *timer)
464{
465 return timer->state & HRTIMER_STATE_PENDING;
466}
467
468/*
469 * Remove a timer from the callback pending list
470 */
471static inline void hrtimer_remove_cb_pending(struct hrtimer *timer)
472{
473 list_del_init(&timer->cb_entry);
474}
475
476/*
477 * Initialize the high resolution related parts of cpu_base
478 */
479static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
480{
481 base->expires_next.tv64 = KTIME_MAX;
482 base->hres_active = 0;
483 INIT_LIST_HEAD(&base->cb_pending);
484}
485
486/*
487 * Initialize the high resolution related parts of a hrtimer
488 */
489static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
490{
491 INIT_LIST_HEAD(&timer->cb_entry);
492}
493
494/*
495 * When High resolution timers are active, try to reprogram. Note, that in case
496 * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
497 * check happens. The timer gets enqueued into the rbtree. The reprogramming
498 * and expiry check is done in the hrtimer_interrupt or in the softirq.
499 */
500static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
501 struct hrtimer_clock_base *base)
502{
503 if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
504
505 /* Timer is expired, act upon the callback mode */
506 switch(timer->cb_mode) {
507 case HRTIMER_CB_IRQSAFE_NO_RESTART:
508 /*
509 * We can call the callback from here. No restart
510 * happens, so no danger of recursion
511 */
512 BUG_ON(timer->function(timer) != HRTIMER_NORESTART);
513 return 1;
514 case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:
515 /*
516 * This is solely for the sched tick emulation with
517 * dynamic tick support to ensure that we do not
518 * restart the tick right on the edge and end up with
519 * the tick timer in the softirq ! The calling site
520 * takes care of this.
521 */
522 return 1;
523 case HRTIMER_CB_IRQSAFE:
524 case HRTIMER_CB_SOFTIRQ:
525 /*
526 * Move everything else into the softirq pending list !
527 */
528 list_add_tail(&timer->cb_entry,
529 &base->cpu_base->cb_pending);
530 timer->state = HRTIMER_STATE_PENDING;
531 raise_softirq(HRTIMER_SOFTIRQ);
532 return 1;
533 default:
534 BUG();
535 }
536 }
537 return 0;
538}
539
540/*
541 * Switch to high resolution mode
542 */
543static void hrtimer_switch_to_hres(void)
544{
545 struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
546 unsigned long flags;
547
548 if (base->hres_active)
549 return;
550
551 local_irq_save(flags);
552
553 if (tick_init_highres()) {
554 local_irq_restore(flags);
555 return;
556 }
557 base->hres_active = 1;
558 base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
559 base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
560
561 tick_setup_sched_timer();
562
563 /* "Retrigger" the interrupt to get things going */
564 retrigger_next_event(NULL);
565 local_irq_restore(flags);
566 printk(KERN_INFO "Switched to high resolution mode on CPU %d\n",
567 smp_processor_id());
568}
569
570#else
571
572static inline int hrtimer_hres_active(void) { return 0; }
573static inline int hrtimer_is_hres_enabled(void) { return 0; }
574static inline void hrtimer_switch_to_hres(void) { }
575static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
576static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
577 struct hrtimer_clock_base *base)
578{
579 return 0;
580}
581static inline int hrtimer_cb_pending(struct hrtimer *timer) { return 0; }
582static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) { }
583static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
584static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
585
586#endif /* CONFIG_HIGH_RES_TIMERS */
587
311/* 588/*
312 * Counterpart to lock_timer_base above: 589 * Counterpart to lock_timer_base above:
313 */ 590 */
@@ -365,7 +642,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
365 * red black tree is O(log(n)). Must hold the base lock. 642 * red black tree is O(log(n)). Must hold the base lock.
366 */ 643 */
367static void enqueue_hrtimer(struct hrtimer *timer, 644static void enqueue_hrtimer(struct hrtimer *timer,
368 struct hrtimer_clock_base *base) 645 struct hrtimer_clock_base *base, int reprogram)
369{ 646{
370 struct rb_node **link = &base->active.rb_node; 647 struct rb_node **link = &base->active.rb_node;
371 struct rb_node *parent = NULL; 648 struct rb_node *parent = NULL;
@@ -391,6 +668,22 @@ static void enqueue_hrtimer(struct hrtimer *timer,
391 * Insert the timer to the rbtree and check whether it 668 * Insert the timer to the rbtree and check whether it
392 * replaces the first pending timer 669 * replaces the first pending timer
393 */ 670 */
671 if (!base->first || timer->expires.tv64 <
672 rb_entry(base->first, struct hrtimer, node)->expires.tv64) {
673 /*
674 * Reprogram the clock event device. When the timer is already
675 * expired hrtimer_enqueue_reprogram has either called the
676 * callback or added it to the pending list and raised the
677 * softirq.
678 *
679 * This is a NOP for !HIGHRES
680 */
681 if (reprogram && hrtimer_enqueue_reprogram(timer, base))
682 return;
683
684 base->first = &timer->node;
685 }
686
394 rb_link_node(&timer->node, parent, link); 687 rb_link_node(&timer->node, parent, link);
395 rb_insert_color(&timer->node, &base->active); 688 rb_insert_color(&timer->node, &base->active);
396 /* 689 /*
@@ -398,28 +691,38 @@ static void enqueue_hrtimer(struct hrtimer *timer,
398 * state of a possibly running callback. 691 * state of a possibly running callback.
399 */ 692 */
400 timer->state |= HRTIMER_STATE_ENQUEUED; 693 timer->state |= HRTIMER_STATE_ENQUEUED;
401
402 if (!base->first || timer->expires.tv64 <
403 rb_entry(base->first, struct hrtimer, node)->expires.tv64)
404 base->first = &timer->node;
405} 694}
406 695
407/* 696/*
408 * __remove_hrtimer - internal function to remove a timer 697 * __remove_hrtimer - internal function to remove a timer
409 * 698 *
410 * Caller must hold the base lock. 699 * Caller must hold the base lock.
700 *
701 * High resolution timer mode reprograms the clock event device when the
702 * timer is the one which expires next. The caller can disable this by setting
703 * reprogram to zero. This is useful, when the context does a reprogramming
704 * anyway (e.g. timer interrupt)
411 */ 705 */
412static void __remove_hrtimer(struct hrtimer *timer, 706static void __remove_hrtimer(struct hrtimer *timer,
413 struct hrtimer_clock_base *base, 707 struct hrtimer_clock_base *base,
414 unsigned long newstate) 708 unsigned long newstate, int reprogram)
415{ 709{
416 /* 710 /* High res. callback list. NOP for !HIGHRES */
417 * Remove the timer from the rbtree and replace the 711 if (hrtimer_cb_pending(timer))
418 * first entry pointer if necessary. 712 hrtimer_remove_cb_pending(timer);
419 */ 713 else {
420 if (base->first == &timer->node) 714 /*
421 base->first = rb_next(&timer->node); 715 * Remove the timer from the rbtree and replace the
422 rb_erase(&timer->node, &base->active); 716 * first entry pointer if necessary.
717 */
718 if (base->first == &timer->node) {
719 base->first = rb_next(&timer->node);
720 /* Reprogram the clock event device. if enabled */
721 if (reprogram && hrtimer_hres_active())
722 hrtimer_force_reprogram(base->cpu_base);
723 }
724 rb_erase(&timer->node, &base->active);
725 }
423 timer->state = newstate; 726 timer->state = newstate;
424} 727}
425 728
@@ -430,7 +733,19 @@ static inline int
430remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) 733remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
431{ 734{
432 if (hrtimer_is_queued(timer)) { 735 if (hrtimer_is_queued(timer)) {
433 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE); 736 int reprogram;
737
738 /*
739 * Remove the timer and force reprogramming when high
740 * resolution mode is active and the timer is on the current
741 * CPU. If we remove a timer on another CPU, reprogramming is
742 * skipped. The interrupt event on this CPU is fired and
743 * reprogramming happens in the interrupt handler. This is a
744 * rare case and less expensive than a smp call.
745 */
746 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
747 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
748 reprogram);
434 return 1; 749 return 1;
435 } 750 }
436 return 0; 751 return 0;
@@ -476,7 +791,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
476 } 791 }
477 timer->expires = tim; 792 timer->expires = tim;
478 793
479 enqueue_hrtimer(timer, new_base); 794 enqueue_hrtimer(timer, new_base, base == new_base);
480 795
481 unlock_hrtimer_base(timer, &flags); 796 unlock_hrtimer_base(timer, &flags);
482 797
@@ -567,17 +882,19 @@ ktime_t hrtimer_get_next_event(void)
567 882
568 spin_lock_irqsave(&cpu_base->lock, flags); 883 spin_lock_irqsave(&cpu_base->lock, flags);
569 884
570 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { 885 if (!hrtimer_hres_active()) {
571 struct hrtimer *timer; 886 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
887 struct hrtimer *timer;
572 888
573 if (!base->first) 889 if (!base->first)
574 continue; 890 continue;
575 891
576 timer = rb_entry(base->first, struct hrtimer, node); 892 timer = rb_entry(base->first, struct hrtimer, node);
577 delta.tv64 = timer->expires.tv64; 893 delta.tv64 = timer->expires.tv64;
578 delta = ktime_sub(delta, base->get_time()); 894 delta = ktime_sub(delta, base->get_time());
579 if (delta.tv64 < mindelta.tv64) 895 if (delta.tv64 < mindelta.tv64)
580 mindelta.tv64 = delta.tv64; 896 mindelta.tv64 = delta.tv64;
897 }
581 } 898 }
582 899
583 spin_unlock_irqrestore(&cpu_base->lock, flags); 900 spin_unlock_irqrestore(&cpu_base->lock, flags);
@@ -607,6 +924,7 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
607 clock_id = CLOCK_MONOTONIC; 924 clock_id = CLOCK_MONOTONIC;
608 925
609 timer->base = &cpu_base->clock_base[clock_id]; 926 timer->base = &cpu_base->clock_base[clock_id];
927 hrtimer_init_timer_hres(timer);
610} 928}
611EXPORT_SYMBOL_GPL(hrtimer_init); 929EXPORT_SYMBOL_GPL(hrtimer_init);
612 930
@@ -629,6 +947,139 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
629} 947}
630EXPORT_SYMBOL_GPL(hrtimer_get_res); 948EXPORT_SYMBOL_GPL(hrtimer_get_res);
631 949
950#ifdef CONFIG_HIGH_RES_TIMERS
951
952/*
953 * High resolution timer interrupt
954 * Called with interrupts disabled
955 */
956void hrtimer_interrupt(struct clock_event_device *dev)
957{
958 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
959 struct hrtimer_clock_base *base;
960 ktime_t expires_next, now;
961 int i, raise = 0;
962
963 BUG_ON(!cpu_base->hres_active);
964 cpu_base->nr_events++;
965 dev->next_event.tv64 = KTIME_MAX;
966
967 retry:
968 now = ktime_get();
969
970 expires_next.tv64 = KTIME_MAX;
971
972 base = cpu_base->clock_base;
973
974 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
975 ktime_t basenow;
976 struct rb_node *node;
977
978 spin_lock(&cpu_base->lock);
979
980 basenow = ktime_add(now, base->offset);
981
982 while ((node = base->first)) {
983 struct hrtimer *timer;
984
985 timer = rb_entry(node, struct hrtimer, node);
986
987 if (basenow.tv64 < timer->expires.tv64) {
988 ktime_t expires;
989
990 expires = ktime_sub(timer->expires,
991 base->offset);
992 if (expires.tv64 < expires_next.tv64)
993 expires_next = expires;
994 break;
995 }
996
997 /* Move softirq callbacks to the pending list */
998 if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
999 __remove_hrtimer(timer, base,
1000 HRTIMER_STATE_PENDING, 0);
1001 list_add_tail(&timer->cb_entry,
1002 &base->cpu_base->cb_pending);
1003 raise = 1;
1004 continue;
1005 }
1006
1007 __remove_hrtimer(timer, base,
1008 HRTIMER_STATE_CALLBACK, 0);
1009
1010 /*
1011 * Note: We clear the CALLBACK bit after
1012 * enqueue_hrtimer to avoid reprogramming of
1013 * the event hardware. This happens at the end
1014 * of this function anyway.
1015 */
1016 if (timer->function(timer) != HRTIMER_NORESTART) {
1017 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1018 enqueue_hrtimer(timer, base, 0);
1019 }
1020 timer->state &= ~HRTIMER_STATE_CALLBACK;
1021 }
1022 spin_unlock(&cpu_base->lock);
1023 base++;
1024 }
1025
1026 cpu_base->expires_next = expires_next;
1027
1028 /* Reprogramming necessary ? */
1029 if (expires_next.tv64 != KTIME_MAX) {
1030 if (tick_program_event(expires_next, 0))
1031 goto retry;
1032 }
1033
1034 /* Raise softirq ? */
1035 if (raise)
1036 raise_softirq(HRTIMER_SOFTIRQ);
1037}
1038
1039static void run_hrtimer_softirq(struct softirq_action *h)
1040{
1041 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1042
1043 spin_lock_irq(&cpu_base->lock);
1044
1045 while (!list_empty(&cpu_base->cb_pending)) {
1046 enum hrtimer_restart (*fn)(struct hrtimer *);
1047 struct hrtimer *timer;
1048 int restart;
1049
1050 timer = list_entry(cpu_base->cb_pending.next,
1051 struct hrtimer, cb_entry);
1052
1053 fn = timer->function;
1054 __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
1055 spin_unlock_irq(&cpu_base->lock);
1056
1057 restart = fn(timer);
1058
1059 spin_lock_irq(&cpu_base->lock);
1060
1061 timer->state &= ~HRTIMER_STATE_CALLBACK;
1062 if (restart == HRTIMER_RESTART) {
1063 BUG_ON(hrtimer_active(timer));
1064 /*
1065 * Enqueue the timer, allow reprogramming of the event
1066 * device
1067 */
1068 enqueue_hrtimer(timer, timer->base, 1);
1069 } else if (hrtimer_active(timer)) {
1070 /*
1071 * If the timer was rearmed on another CPU, reprogram
1072 * the event device.
1073 */
1074 if (timer->base->first == &timer->node)
1075 hrtimer_reprogram(timer, timer->base);
1076 }
1077 }
1078 spin_unlock_irq(&cpu_base->lock);
1079}
1080
1081#endif /* CONFIG_HIGH_RES_TIMERS */
1082
632/* 1083/*
633 * Expire the per base hrtimer-queue: 1084 * Expire the per base hrtimer-queue:
634 */ 1085 */
@@ -656,7 +1107,7 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
656 break; 1107 break;
657 1108
658 fn = timer->function; 1109 fn = timer->function;
659 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK); 1110 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
660 spin_unlock_irq(&cpu_base->lock); 1111 spin_unlock_irq(&cpu_base->lock);
661 1112
662 restart = fn(timer); 1113 restart = fn(timer);
@@ -666,7 +1117,7 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
666 timer->state &= ~HRTIMER_STATE_CALLBACK; 1117 timer->state &= ~HRTIMER_STATE_CALLBACK;
667 if (restart != HRTIMER_NORESTART) { 1118 if (restart != HRTIMER_NORESTART) {
668 BUG_ON(hrtimer_active(timer)); 1119 BUG_ON(hrtimer_active(timer));
669 enqueue_hrtimer(timer, base); 1120 enqueue_hrtimer(timer, base, 0);
670 } 1121 }
671 } 1122 }
672 spin_unlock_irq(&cpu_base->lock); 1123 spin_unlock_irq(&cpu_base->lock);
@@ -674,12 +1125,19 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
674 1125
675/* 1126/*
676 * Called from timer softirq every jiffy, expire hrtimers: 1127 * Called from timer softirq every jiffy, expire hrtimers:
1128 *
1129 * For HRT its the fall back code to run the softirq in the timer
1130 * softirq context in case the hrtimer initialization failed or has
1131 * not been done yet.
677 */ 1132 */
678void hrtimer_run_queues(void) 1133void hrtimer_run_queues(void)
679{ 1134{
680 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); 1135 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
681 int i; 1136 int i;
682 1137
1138 if (hrtimer_hres_active())
1139 return;
1140
683 /* 1141 /*
684 * This _is_ ugly: We have to check in the softirq context, 1142 * This _is_ ugly: We have to check in the softirq context,
685 * whether we can switch to highres and / or nohz mode. The 1143 * whether we can switch to highres and / or nohz mode. The
@@ -688,7 +1146,8 @@ void hrtimer_run_queues(void)
688 * check bit in the tick_oneshot code, otherwise we might 1146 * check bit in the tick_oneshot code, otherwise we might
689 * deadlock vs. xtime_lock. 1147 * deadlock vs. xtime_lock.
690 */ 1148 */
691 tick_check_oneshot_change(1); 1149 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1150 hrtimer_switch_to_hres();
692 1151
693 hrtimer_get_softirq_time(cpu_base); 1152 hrtimer_get_softirq_time(cpu_base);
694 1153
@@ -716,6 +1175,9 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
716{ 1175{
717 sl->timer.function = hrtimer_wakeup; 1176 sl->timer.function = hrtimer_wakeup;
718 sl->task = task; 1177 sl->task = task;
1178#ifdef CONFIG_HIGH_RES_TIMERS
1179 sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_RESTART;
1180#endif
719} 1181}
720 1182
721static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) 1183static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
@@ -726,7 +1188,8 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
726 set_current_state(TASK_INTERRUPTIBLE); 1188 set_current_state(TASK_INTERRUPTIBLE);
727 hrtimer_start(&t->timer, t->timer.expires, mode); 1189 hrtimer_start(&t->timer, t->timer.expires, mode);
728 1190
729 schedule(); 1191 if (likely(t->task))
1192 schedule();
730 1193
731 hrtimer_cancel(&t->timer); 1194 hrtimer_cancel(&t->timer);
732 mode = HRTIMER_MODE_ABS; 1195 mode = HRTIMER_MODE_ABS;
@@ -831,6 +1294,7 @@ static void __devinit init_hrtimers_cpu(int cpu)
831 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) 1294 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
832 cpu_base->clock_base[i].cpu_base = cpu_base; 1295 cpu_base->clock_base[i].cpu_base = cpu_base;
833 1296
1297 hrtimer_init_hres(cpu_base);
834} 1298}
835 1299
836#ifdef CONFIG_HOTPLUG_CPU 1300#ifdef CONFIG_HOTPLUG_CPU
@@ -843,10 +1307,13 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
843 1307
844 while ((node = rb_first(&old_base->active))) { 1308 while ((node = rb_first(&old_base->active))) {
845 timer = rb_entry(node, struct hrtimer, node); 1309 timer = rb_entry(node, struct hrtimer, node);
846 BUG_ON(timer->state & HRTIMER_STATE_CALLBACK); 1310 BUG_ON(hrtimer_callback_running(timer));
847 __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE); 1311 __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
848 timer->base = new_base; 1312 timer->base = new_base;
849 enqueue_hrtimer(timer, new_base); 1313 /*
1314 * Enqueue the timer. Allow reprogramming of the event device
1315 */
1316 enqueue_hrtimer(timer, new_base, 1);
850 } 1317 }
851} 1318}
852 1319
@@ -859,6 +1326,8 @@ static void migrate_hrtimers(int cpu)
859 old_base = &per_cpu(hrtimer_bases, cpu); 1326 old_base = &per_cpu(hrtimer_bases, cpu);
860 new_base = &get_cpu_var(hrtimer_bases); 1327 new_base = &get_cpu_var(hrtimer_bases);
861 1328
1329 tick_cancel_sched_timer(cpu);
1330
862 local_irq_disable(); 1331 local_irq_disable();
863 1332
864 spin_lock(&new_base->lock); 1333 spin_lock(&new_base->lock);
@@ -910,5 +1379,8 @@ void __init hrtimers_init(void)
910 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, 1379 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
911 (void *)(long)smp_processor_id()); 1380 (void *)(long)smp_processor_id());
912 register_cpu_notifier(&hrtimers_nb); 1381 register_cpu_notifier(&hrtimers_nb);
1382#ifdef CONFIG_HIGH_RES_TIMERS
1383 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
1384#endif
913} 1385}
914 1386