| Message ID | dc479af0df0a087f24719237e7af687caa71e0d1.1395832156.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Wed, 26 Mar 2014, Viresh Kumar wrote: > Active_bases field of struct hrtimer_cpu_base is used at only one place, i.e. > hrtimer_interrupt() and at that place too we can easily use timerqueue_getnext() > instead to achieve the same result. I don't think this will have any performance > degradation issues and so removing this field. Instead of removing it we should actually use ffs and avoid the whole looping. That was the intention in the first place, but I never wrote the patch... Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 26 March 2014 22:58, Thomas Gleixner <tglx@linutronix.de> wrote: > Instead of removing it we should actually use ffs and avoid the whole > looping. That was the intention in the first place, but I never wrote > the patch... I thought about that and then using ffs for a field of which only 4 bits are useful didn't looked too convincing to me :) But, probably it will make things slightly better in case this routine is heavily used. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 6f524db..cb6a315 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -165,7 +165,6 @@ enum hrtimer_base_type { * struct hrtimer_cpu_base - the per cpu clock bases * @lock: lock protecting the base and associated clock bases * and timers - * @active_bases: Bitfield to mark bases with active timers * @clock_was_set: Indicates that clock was set from irq context. * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() @@ -179,7 +178,6 @@ enum hrtimer_base_type { */ struct hrtimer_cpu_base { raw_spinlock_t lock; - unsigned int active_bases; unsigned int clock_was_set; #ifdef CONFIG_HIGH_RES_TIMERS ktime_t expires_next; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 1e4eedb..f14d861 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -865,7 +865,6 @@ 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 @@ -909,8 +908,6 @@ static void __remove_hrtimer(struct hrtimer *timer, } #endif } - if (!timerqueue_getnext(&base->active)) - base->cpu_base->active_bases &= ~(1 << base->index); out: timer->state = newstate; } @@ -1284,14 +1281,13 @@ retry: cpu_base->expires_next.tv64 = KTIME_MAX; for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - struct hrtimer_clock_base *base; + struct hrtimer_clock_base *base = cpu_base->clock_base + i; struct timerqueue_node *node; ktime_t basenow; - if (!(cpu_base->active_bases & (1 << i))) + if (!timerqueue_getnext(&base->active)) continue; - base = cpu_base->clock_base + i; basenow = ktime_add(now, base->offset); while ((node = timerqueue_getnext(&base->active))) {
Active_bases field of struct hrtimer_cpu_base is used at only one place, i.e. hrtimer_interrupt() and at that place too we can easily use timerqueue_getnext() instead to achieve the same result. I don't think this will have any performance degradation issues and so removing this field. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- include/linux/hrtimer.h | 2 -- kernel/hrtimer.c | 8 ++------ 2 files changed, 2 insertions(+), 8 deletions(-)