From ab8177bc53e8ae3a3ba6d200ce2c2dae263f7ee5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 20 May 2011 13:05:15 +0200 Subject: [PATCH] hrtimers: Avoid touching inactive timer bases Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by: Thomas Gleixner Reviewed-by: Peter Zijlstra --- include/linux/hrtimer.h | 7 +++++-- include/linux/thread_info.h | 2 +- kernel/hrtimer.c | 29 ++++++++++++++++++----------- kernel/posix-cpu-timers.c | 4 ++-- kernel/posix-timers.c | 2 +- kernel/time/alarmtimer.c | 4 ++-- 6 files changed, 29 insertions(+), 19 deletions(-) diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index cc5f5f51db10..771c95802edc 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -143,7 +143,8 @@ struct hrtimer_sleeper { */ struct hrtimer_clock_base { struct hrtimer_cpu_base *cpu_base; - clockid_t index; + int index; + clockid_t clockid; struct timerqueue_head active; ktime_t resolution; ktime_t (*get_time)(void); @@ -162,7 +163,7 @@ enum hrtimer_base_type { * struct hrtimer_cpu_base - the per cpu clock bases * @lock: lock protecting the base and associated clock bases * and timers - * @clock_base: array of clock bases for this cpu + * @active_bases: Bitfield to mark bases with active timers * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() * @hres_active: State of high resolution mode @@ -171,9 +172,11 @@ enum hrtimer_base_type { * @nr_retries: Total number of hrtimer interrupt retries * @nr_hangs: Total number of hrtimer interrupt hangs * @max_hang_time: Maximum time spent in hrtimer_interrupt + * @clock_base: array of clock bases for this cpu */ struct hrtimer_cpu_base { raw_spinlock_t lock; + unsigned long active_bases; #ifdef CONFIG_HIGH_RES_TIMERS ktime_t expires_next; int hres_active; diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 20fc303947d3..8d03f079688c 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -29,7 +29,7 @@ struct restart_block { } futex; /* For nanosleep */ struct { - clockid_t index; + clockid_t clockid; struct timespec __user *rmtp; #ifdef CONFIG_COMPAT struct compat_timespec __user *compat_rmtp; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 26dd32f9f6b2..1b08f6d67f12 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -64,17 +64,20 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = .clock_base = { { - .index = CLOCK_REALTIME, + .index = HRTIMER_BASE_REALTIME, + .clockid = CLOCK_REALTIME, .get_time = &ktime_get_real, .resolution = KTIME_LOW_RES, }, { - .index = CLOCK_MONOTONIC, + .index = HRTIMER_BASE_MONOTONIC, + .clockid = CLOCK_MONOTONIC, .get_time = &ktime_get, .resolution = KTIME_LOW_RES, }, { - .index = CLOCK_BOOTTIME, + .index = HRTIMER_BASE_BOOTTIME, + .clockid = CLOCK_BOOTTIME, .get_time = &ktime_get_boottime, .resolution = KTIME_LOW_RES, }, @@ -196,7 +199,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, struct hrtimer_cpu_base *new_cpu_base; int this_cpu = smp_processor_id(); int cpu = hrtimer_get_target(this_cpu, pinned); - int basenum = hrtimer_clockid_to_base(base->index); + int basenum = base->index; again: new_cpu_base = &per_cpu(hrtimer_bases, cpu); @@ -857,6 +860,7 @@ static int enqueue_hrtimer(struct hrtimer *timer, debug_activate(timer); timerqueue_add(&base->active, &timer->node); + base->cpu_base->active_bases |= 1 << base->index; /* * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the @@ -898,6 +902,8 @@ static void __remove_hrtimer(struct hrtimer *timer, #endif } timerqueue_del(&base->active, &timer->node); + if (!timerqueue_getnext(&base->active)) + base->cpu_base->active_bases &= ~(1 << base->index); out: timer->state = newstate; } @@ -1235,7 +1241,6 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) void hrtimer_interrupt(struct clock_event_device *dev) { struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - struct hrtimer_clock_base *base; ktime_t expires_next, now, entry_time, delta; int i, retries = 0; @@ -1257,12 +1262,15 @@ retry: */ cpu_base->expires_next.tv64 = KTIME_MAX; - base = cpu_base->clock_base; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - ktime_t basenow; + struct hrtimer_clock_base *base; struct timerqueue_node *node; + ktime_t basenow; + + if (!(cpu_base->active_bases & (1 << i))) + continue; + base = cpu_base->clock_base + i; basenow = ktime_add(now, base->offset); while ((node = timerqueue_getnext(&base->active))) { @@ -1295,7 +1303,6 @@ retry: __run_hrtimer(timer, &basenow); } - base++; } /* @@ -1526,7 +1533,7 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) struct timespec __user *rmtp; int ret = 0; - hrtimer_init_on_stack(&t.timer, restart->nanosleep.index, + hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, HRTIMER_MODE_ABS); hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); @@ -1578,7 +1585,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, restart = ¤t_thread_info()->restart_block; restart->fn = hrtimer_nanosleep_restart; - restart->nanosleep.index = t.timer.base->index; + restart->nanosleep.clockid = t.timer.base->clockid; restart->nanosleep.rmtp = rmtp; restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 0791b13df7bf..58f405b581e7 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1514,7 +1514,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags, return -EFAULT; restart_block->fn = posix_cpu_nsleep_restart; - restart_block->nanosleep.index = which_clock; + restart_block->nanosleep.clockid = which_clock; restart_block->nanosleep.rmtp = rmtp; restart_block->nanosleep.expires = timespec_to_ns(rqtp); } @@ -1523,7 +1523,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags, static long posix_cpu_nsleep_restart(struct restart_block *restart_block) { - clockid_t which_clock = restart_block->nanosleep.index; + clockid_t which_clock = restart_block->nanosleep.clockid; struct timespec t; struct itimerspec it; int error; diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e5498d7405c3..a1b5edf1bf92 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -1056,7 +1056,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, */ long clock_nanosleep_restart(struct restart_block *restart_block) { - clockid_t which_clock = restart_block->nanosleep.index; + clockid_t which_clock = restart_block->nanosleep.clockid; struct k_clock *kc = clockid_to_kclock(which_clock); if (WARN_ON_ONCE(!kc || !kc->nsleep_restart)) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index c6027fe9a4e6..2d966244ea60 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -494,7 +494,7 @@ static int update_rmtp(ktime_t exp, enum alarmtimer_type type, */ static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) { - enum alarmtimer_type type = restart->nanosleep.index; + enum alarmtimer_type type = restart->nanosleep.clockid; ktime_t exp; struct timespec __user *rmtp; struct alarm alarm; @@ -573,7 +573,7 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, restart = ¤t_thread_info()->restart_block; restart->fn = alarm_timer_nsleep_restart; - restart->nanosleep.index = type; + restart->nanosleep.clockid = type; restart->nanosleep.expires = exp.tv64; restart->nanosleep.rmtp = rmtp; ret = -ERESTART_RESTARTBLOCK; -- 2.30.2