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-rw-r--r--kernel/hrtimer.c184
1 files changed, 98 insertions, 86 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 83fc50416b1d..89a9f535b4ce 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1,8 +1,9 @@
1/* 1/*
2 * linux/kernel/hrtimer.c 2 * linux/kernel/hrtimer.c
3 * 3 *
4 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> 4 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
5 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar 5 * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
6 * Copyright(C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
6 * 7 *
7 * High-resolution kernel timers 8 * High-resolution kernel timers
8 * 9 *
@@ -79,21 +80,22 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
79 * This ensures that we capture erroneous accesses to these clock ids 80 * This ensures that we capture erroneous accesses to these clock ids
80 * rather than moving them into the range of valid clock id's. 81 * rather than moving them into the range of valid clock id's.
81 */ 82 */
82 83static DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
83#define MAX_HRTIMER_BASES 2
84
85static DEFINE_PER_CPU(struct hrtimer_base, hrtimer_bases[MAX_HRTIMER_BASES]) =
86{ 84{
85
86 .clock_base =
87 { 87 {
88 .index = CLOCK_REALTIME, 88 {
89 .get_time = &ktime_get_real, 89 .index = CLOCK_REALTIME,
90 .resolution = KTIME_REALTIME_RES, 90 .get_time = &ktime_get_real,
91 }, 91 .resolution = KTIME_REALTIME_RES,
92 { 92 },
93 .index = CLOCK_MONOTONIC, 93 {
94 .get_time = &ktime_get, 94 .index = CLOCK_MONOTONIC,
95 .resolution = KTIME_MONOTONIC_RES, 95 .get_time = &ktime_get,
96 }, 96 .resolution = KTIME_MONOTONIC_RES,
97 },
98 }
97}; 99};
98 100
99/** 101/**
@@ -125,7 +127,7 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
125 * Get the coarse grained time at the softirq based on xtime and 127 * Get the coarse grained time at the softirq based on xtime and
126 * wall_to_monotonic. 128 * wall_to_monotonic.
127 */ 129 */
128static void hrtimer_get_softirq_time(struct hrtimer_base *base) 130static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
129{ 131{
130 ktime_t xtim, tomono; 132 ktime_t xtim, tomono;
131 struct timespec xts; 133 struct timespec xts;
@@ -142,8 +144,9 @@ static void hrtimer_get_softirq_time(struct hrtimer_base *base)
142 144
143 xtim = timespec_to_ktime(xts); 145 xtim = timespec_to_ktime(xts);
144 tomono = timespec_to_ktime(wall_to_monotonic); 146 tomono = timespec_to_ktime(wall_to_monotonic);
145 base[CLOCK_REALTIME].softirq_time = xtim; 147 base->clock_base[CLOCK_REALTIME].softirq_time = xtim;
146 base[CLOCK_MONOTONIC].softirq_time = ktime_add(xtim, tomono); 148 base->clock_base[CLOCK_MONOTONIC].softirq_time =
149 ktime_add(xtim, tomono);
147} 150}
148 151
149/* 152/*
@@ -166,19 +169,20 @@ static void hrtimer_get_softirq_time(struct hrtimer_base *base)
166 * possible to set timer->base = NULL and drop the lock: the timer remains 169 * possible to set timer->base = NULL and drop the lock: the timer remains
167 * locked. 170 * locked.
168 */ 171 */
169static struct hrtimer_base *lock_hrtimer_base(const struct hrtimer *timer, 172static
170 unsigned long *flags) 173struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
174 unsigned long *flags)
171{ 175{
172 struct hrtimer_base *base; 176 struct hrtimer_clock_base *base;
173 177
174 for (;;) { 178 for (;;) {
175 base = timer->base; 179 base = timer->base;
176 if (likely(base != NULL)) { 180 if (likely(base != NULL)) {
177 spin_lock_irqsave(&base->lock, *flags); 181 spin_lock_irqsave(&base->cpu_base->lock, *flags);
178 if (likely(base == timer->base)) 182 if (likely(base == timer->base))
179 return base; 183 return base;
180 /* The timer has migrated to another CPU: */ 184 /* The timer has migrated to another CPU: */
181 spin_unlock_irqrestore(&base->lock, *flags); 185 spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
182 } 186 }
183 cpu_relax(); 187 cpu_relax();
184 } 188 }
@@ -187,12 +191,14 @@ static struct hrtimer_base *lock_hrtimer_base(const struct hrtimer *timer,
187/* 191/*
188 * Switch the timer base to the current CPU when possible. 192 * Switch the timer base to the current CPU when possible.
189 */ 193 */
190static inline struct hrtimer_base * 194static inline struct hrtimer_clock_base *
191switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base) 195switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base)
192{ 196{
193 struct hrtimer_base *new_base; 197 struct hrtimer_clock_base *new_base;
198 struct hrtimer_cpu_base *new_cpu_base;
194 199
195 new_base = &__get_cpu_var(hrtimer_bases)[base->index]; 200 new_cpu_base = &__get_cpu_var(hrtimer_bases);
201 new_base = &new_cpu_base->clock_base[base->index];
196 202
197 if (base != new_base) { 203 if (base != new_base) {
198 /* 204 /*
@@ -204,13 +210,13 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base)
204 * completed. There is no conflict as we hold the lock until 210 * completed. There is no conflict as we hold the lock until
205 * the timer is enqueued. 211 * the timer is enqueued.
206 */ 212 */
207 if (unlikely(base->curr_timer == timer)) 213 if (unlikely(base->cpu_base->curr_timer == timer))
208 return base; 214 return base;
209 215
210 /* See the comment in lock_timer_base() */ 216 /* See the comment in lock_timer_base() */
211 timer->base = NULL; 217 timer->base = NULL;
212 spin_unlock(&base->lock); 218 spin_unlock(&base->cpu_base->lock);
213 spin_lock(&new_base->lock); 219 spin_lock(&new_base->cpu_base->lock);
214 timer->base = new_base; 220 timer->base = new_base;
215 } 221 }
216 return new_base; 222 return new_base;
@@ -220,12 +226,12 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base)
220 226
221#define set_curr_timer(b, t) do { } while (0) 227#define set_curr_timer(b, t) do { } while (0)
222 228
223static inline struct hrtimer_base * 229static inline struct hrtimer_clock_base *
224lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) 230lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
225{ 231{
226 struct hrtimer_base *base = timer->base; 232 struct hrtimer_clock_base *base = timer->base;
227 233
228 spin_lock_irqsave(&base->lock, *flags); 234 spin_lock_irqsave(&base->cpu_base->lock, *flags);
229 235
230 return base; 236 return base;
231} 237}
@@ -305,7 +311,7 @@ void hrtimer_notify_resume(void)
305static inline 311static inline
306void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) 312void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
307{ 313{
308 spin_unlock_irqrestore(&timer->base->lock, *flags); 314 spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
309} 315}
310 316
311/** 317/**
@@ -355,7 +361,8 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
355 * The timer is inserted in expiry order. Insertion into the 361 * The timer is inserted in expiry order. Insertion into the
356 * red black tree is O(log(n)). Must hold the base lock. 362 * red black tree is O(log(n)). Must hold the base lock.
357 */ 363 */
358static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) 364static void enqueue_hrtimer(struct hrtimer *timer,
365 struct hrtimer_clock_base *base)
359{ 366{
360 struct rb_node **link = &base->active.rb_node; 367 struct rb_node **link = &base->active.rb_node;
361 struct rb_node *parent = NULL; 368 struct rb_node *parent = NULL;
@@ -394,7 +401,8 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
394 * 401 *
395 * Caller must hold the base lock. 402 * Caller must hold the base lock.
396 */ 403 */
397static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) 404static void __remove_hrtimer(struct hrtimer *timer,
405 struct hrtimer_clock_base *base)
398{ 406{
399 /* 407 /*
400 * Remove the timer from the rbtree and replace the 408 * Remove the timer from the rbtree and replace the
@@ -410,7 +418,7 @@ static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
410 * remove hrtimer, called with base lock held 418 * remove hrtimer, called with base lock held
411 */ 419 */
412static inline int 420static inline int
413remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) 421remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
414{ 422{
415 if (hrtimer_active(timer)) { 423 if (hrtimer_active(timer)) {
416 __remove_hrtimer(timer, base); 424 __remove_hrtimer(timer, base);
@@ -432,7 +440,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
432int 440int
433hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) 441hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
434{ 442{
435 struct hrtimer_base *base, *new_base; 443 struct hrtimer_clock_base *base, *new_base;
436 unsigned long flags; 444 unsigned long flags;
437 int ret; 445 int ret;
438 446
@@ -479,13 +487,13 @@ EXPORT_SYMBOL_GPL(hrtimer_start);
479 */ 487 */
480int hrtimer_try_to_cancel(struct hrtimer *timer) 488int hrtimer_try_to_cancel(struct hrtimer *timer)
481{ 489{
482 struct hrtimer_base *base; 490 struct hrtimer_clock_base *base;
483 unsigned long flags; 491 unsigned long flags;
484 int ret = -1; 492 int ret = -1;
485 493
486 base = lock_hrtimer_base(timer, &flags); 494 base = lock_hrtimer_base(timer, &flags);
487 495
488 if (base->curr_timer != timer) 496 if (base->cpu_base->curr_timer != timer)
489 ret = remove_hrtimer(timer, base); 497 ret = remove_hrtimer(timer, base);
490 498
491 unlock_hrtimer_base(timer, &flags); 499 unlock_hrtimer_base(timer, &flags);
@@ -521,12 +529,12 @@ EXPORT_SYMBOL_GPL(hrtimer_cancel);
521 */ 529 */
522ktime_t hrtimer_get_remaining(const struct hrtimer *timer) 530ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
523{ 531{
524 struct hrtimer_base *base; 532 struct hrtimer_clock_base *base;
525 unsigned long flags; 533 unsigned long flags;
526 ktime_t rem; 534 ktime_t rem;
527 535
528 base = lock_hrtimer_base(timer, &flags); 536 base = lock_hrtimer_base(timer, &flags);
529 rem = ktime_sub(timer->expires, timer->base->get_time()); 537 rem = ktime_sub(timer->expires, base->get_time());
530 unlock_hrtimer_base(timer, &flags); 538 unlock_hrtimer_base(timer, &flags);
531 539
532 return rem; 540 return rem;
@@ -542,26 +550,29 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
542 */ 550 */
543ktime_t hrtimer_get_next_event(void) 551ktime_t hrtimer_get_next_event(void)
544{ 552{
545 struct hrtimer_base *base = __get_cpu_var(hrtimer_bases); 553 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
554 struct hrtimer_clock_base *base = cpu_base->clock_base;
546 ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; 555 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
547 unsigned long flags; 556 unsigned long flags;
548 int i; 557 int i;
549 558
550 for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) { 559 spin_lock_irqsave(&cpu_base->lock, flags);
560
561 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
551 struct hrtimer *timer; 562 struct hrtimer *timer;
552 563
553 spin_lock_irqsave(&base->lock, flags); 564 if (!base->first)
554 if (!base->first) {
555 spin_unlock_irqrestore(&base->lock, flags);
556 continue; 565 continue;
557 } 566
558 timer = rb_entry(base->first, struct hrtimer, node); 567 timer = rb_entry(base->first, struct hrtimer, node);
559 delta.tv64 = timer->expires.tv64; 568 delta.tv64 = timer->expires.tv64;
560 spin_unlock_irqrestore(&base->lock, flags);
561 delta = ktime_sub(delta, base->get_time()); 569 delta = ktime_sub(delta, base->get_time());
562 if (delta.tv64 < mindelta.tv64) 570 if (delta.tv64 < mindelta.tv64)
563 mindelta.tv64 = delta.tv64; 571 mindelta.tv64 = delta.tv64;
564 } 572 }
573
574 spin_unlock_irqrestore(&cpu_base->lock, flags);
575
565 if (mindelta.tv64 < 0) 576 if (mindelta.tv64 < 0)
566 mindelta.tv64 = 0; 577 mindelta.tv64 = 0;
567 return mindelta; 578 return mindelta;
@@ -577,16 +588,16 @@ ktime_t hrtimer_get_next_event(void)
577void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, 588void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
578 enum hrtimer_mode mode) 589 enum hrtimer_mode mode)
579{ 590{
580 struct hrtimer_base *bases; 591 struct hrtimer_cpu_base *cpu_base;
581 592
582 memset(timer, 0, sizeof(struct hrtimer)); 593 memset(timer, 0, sizeof(struct hrtimer));
583 594
584 bases = __raw_get_cpu_var(hrtimer_bases); 595 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
585 596
586 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) 597 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
587 clock_id = CLOCK_MONOTONIC; 598 clock_id = CLOCK_MONOTONIC;
588 599
589 timer->base = &bases[clock_id]; 600 timer->base = &cpu_base->clock_base[clock_id];
590 rb_set_parent(&timer->node, &timer->node); 601 rb_set_parent(&timer->node, &timer->node);
591} 602}
592EXPORT_SYMBOL_GPL(hrtimer_init); 603EXPORT_SYMBOL_GPL(hrtimer_init);
@@ -601,10 +612,10 @@ EXPORT_SYMBOL_GPL(hrtimer_init);
601 */ 612 */
602int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) 613int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
603{ 614{
604 struct hrtimer_base *bases; 615 struct hrtimer_cpu_base *cpu_base;
605 616
606 bases = __raw_get_cpu_var(hrtimer_bases); 617 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
607 *tp = ktime_to_timespec(bases[which_clock].resolution); 618 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
608 619
609 return 0; 620 return 0;
610} 621}
@@ -613,9 +624,11 @@ EXPORT_SYMBOL_GPL(hrtimer_get_res);
613/* 624/*
614 * Expire the per base hrtimer-queue: 625 * Expire the per base hrtimer-queue:
615 */ 626 */
616static inline void run_hrtimer_queue(struct hrtimer_base *base) 627static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
628 int index)
617{ 629{
618 struct rb_node *node; 630 struct rb_node *node;
631 struct hrtimer_clock_base *base = &cpu_base->clock_base[index];
619 632
620 if (!base->first) 633 if (!base->first)
621 return; 634 return;
@@ -623,7 +636,7 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
623 if (base->get_softirq_time) 636 if (base->get_softirq_time)
624 base->softirq_time = base->get_softirq_time(); 637 base->softirq_time = base->get_softirq_time();
625 638
626 spin_lock_irq(&base->lock); 639 spin_lock_irq(&cpu_base->lock);
627 640
628 while ((node = base->first)) { 641 while ((node = base->first)) {
629 struct hrtimer *timer; 642 struct hrtimer *timer;
@@ -635,21 +648,21 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
635 break; 648 break;
636 649
637 fn = timer->function; 650 fn = timer->function;
638 set_curr_timer(base, timer); 651 set_curr_timer(cpu_base, timer);
639 __remove_hrtimer(timer, base); 652 __remove_hrtimer(timer, base);
640 spin_unlock_irq(&base->lock); 653 spin_unlock_irq(&cpu_base->lock);
641 654
642 restart = fn(timer); 655 restart = fn(timer);
643 656
644 spin_lock_irq(&base->lock); 657 spin_lock_irq(&cpu_base->lock);
645 658
646 if (restart != HRTIMER_NORESTART) { 659 if (restart != HRTIMER_NORESTART) {
647 BUG_ON(hrtimer_active(timer)); 660 BUG_ON(hrtimer_active(timer));
648 enqueue_hrtimer(timer, base); 661 enqueue_hrtimer(timer, base);
649 } 662 }
650 } 663 }
651 set_curr_timer(base, NULL); 664 set_curr_timer(cpu_base, NULL);
652 spin_unlock_irq(&base->lock); 665 spin_unlock_irq(&cpu_base->lock);
653} 666}
654 667
655/* 668/*
@@ -657,13 +670,13 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
657 */ 670 */
658void hrtimer_run_queues(void) 671void hrtimer_run_queues(void)
659{ 672{
660 struct hrtimer_base *base = __get_cpu_var(hrtimer_bases); 673 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
661 int i; 674 int i;
662 675
663 hrtimer_get_softirq_time(base); 676 hrtimer_get_softirq_time(cpu_base);
664 677
665 for (i = 0; i < MAX_HRTIMER_BASES; i++) 678 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
666 run_hrtimer_queue(&base[i]); 679 run_hrtimer_queue(cpu_base, i);
667} 680}
668 681
669/* 682/*
@@ -792,19 +805,21 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
792 */ 805 */
793static void __devinit init_hrtimers_cpu(int cpu) 806static void __devinit init_hrtimers_cpu(int cpu)
794{ 807{
795 struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu); 808 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
796 int i; 809 int i;
797 810
798 for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) { 811 spin_lock_init(&cpu_base->lock);
799 spin_lock_init(&base->lock); 812 lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
800 lockdep_set_class(&base->lock, &base->lock_key); 813
801 } 814 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
815 cpu_base->clock_base[i].cpu_base = cpu_base;
816
802} 817}
803 818
804#ifdef CONFIG_HOTPLUG_CPU 819#ifdef CONFIG_HOTPLUG_CPU
805 820
806static void migrate_hrtimer_list(struct hrtimer_base *old_base, 821static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
807 struct hrtimer_base *new_base) 822 struct hrtimer_clock_base *new_base)
808{ 823{
809 struct hrtimer *timer; 824 struct hrtimer *timer;
810 struct rb_node *node; 825 struct rb_node *node;
@@ -819,29 +834,26 @@ static void migrate_hrtimer_list(struct hrtimer_base *old_base,
819 834
820static void migrate_hrtimers(int cpu) 835static void migrate_hrtimers(int cpu)
821{ 836{
822 struct hrtimer_base *old_base, *new_base; 837 struct hrtimer_cpu_base *old_base, *new_base;
823 int i; 838 int i;
824 839
825 BUG_ON(cpu_online(cpu)); 840 BUG_ON(cpu_online(cpu));
826 old_base = per_cpu(hrtimer_bases, cpu); 841 old_base = &per_cpu(hrtimer_bases, cpu);
827 new_base = get_cpu_var(hrtimer_bases); 842 new_base = &get_cpu_var(hrtimer_bases);
828 843
829 local_irq_disable(); 844 local_irq_disable();
830 845
831 for (i = 0; i < MAX_HRTIMER_BASES; i++) { 846 spin_lock(&new_base->lock);
832 847 spin_lock(&old_base->lock);
833 spin_lock(&new_base->lock);
834 spin_lock(&old_base->lock);
835 848
849 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
836 BUG_ON(old_base->curr_timer); 850 BUG_ON(old_base->curr_timer);
837 851
838 migrate_hrtimer_list(old_base, new_base); 852 migrate_hrtimer_list(&old_base->clock_base[i],
839 853 &new_base->clock_base[i]);
840 spin_unlock(&old_base->lock);
841 spin_unlock(&new_base->lock);
842 old_base++;
843 new_base++;
844 } 854 }
855 spin_unlock(&old_base->lock);
856 spin_unlock(&new_base->lock);
845 857
846 local_irq_enable(); 858 local_irq_enable();
847 put_cpu_var(hrtimer_bases); 859 put_cpu_var(hrtimer_bases);