From 34aee88a02ba296a8e8c9523cdf77147731903f1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 14 Apr 2015 21:08:41 +0000 Subject: [PATCH] hrtimer: Use cpu_base->active_base for hotpath iterators The active_bases field is guaranteed to be in sync with the timerqueue of the corresponding clock base. So we can use it for iterating over the clock bases. This allows to break out early if no more active clock bases are available and avoids touching the cache lines of inactive clock bases. Signed-off-by: Thomas Gleixner Reviewed-by: Preeti U Murthy Acked-by: Peter Zijlstra Cc: Viresh Kumar Cc: Marcelo Tosatti Cc: Frederic Weisbecker Link: http://lkml.kernel.org/r/20150414203501.322887675@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/time/hrtimer.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 9bbfe33f6575..fce0ccf97b51 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -419,16 +419,16 @@ static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base) { struct hrtimer_clock_base *base = cpu_base->clock_base; ktime_t expires, expires_next = { .tv64 = KTIME_MAX }; - int i; + unsigned int active = cpu_base->active_bases; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { + for (; active; base++, active >>= 1) { struct timerqueue_node *next; struct hrtimer *timer; - next = timerqueue_getnext(&base->active); - if (!next) + if (!(active & 0x01)) continue; + next = timerqueue_getnext(&base->active); timer = container_of(next, struct hrtimer, node); expires = ktime_sub(hrtimer_get_expires(timer), base->offset); if (expires.tv64 < expires_next.tv64) @@ -1214,17 +1214,16 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) { - int i; + struct hrtimer_clock_base *base = cpu_base->clock_base; + unsigned int active = cpu_base->active_bases; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - struct hrtimer_clock_base *base; + for (; active; base++, active >>= 1) { struct timerqueue_node *node; ktime_t basenow; - if (!(cpu_base->active_bases & (1 << i))) + if (!(active & 0x01)) continue; - base = cpu_base->clock_base + i; basenow = ktime_add(now, base->offset); while ((node = timerqueue_getnext(&base->active))) { -- 2.20.1