Messages in this thread | | | Date | Fri, 4 May 2012 14:20:16 +0200 | Subject | Re: [PATCH v1 1/6] timer: make __next_timer_interrupt explicit about no future event | From | Frederic Weisbecker <> |
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2012/5/4 Frederic Weisbecker <fweisbec@gmail.com>: > On Thu, May 03, 2012 at 05:55:57PM +0300, Gilad Ben-Yossef wrote: >> @@ -1317,9 +1322,15 @@ unsigned long get_next_timer_interrupt(unsigned long now) >> if (cpu_is_offline(smp_processor_id())) >> return now + NEXT_TIMER_MAX_DELTA; >> spin_lock(&base->lock); >> - if (time_before_eq(base->next_timer, base->timer_jiffies)) >> - base->next_timer = __next_timer_interrupt(base); >> - expires = base->next_timer; >> + if (time_before_eq(base->next_timer, base->timer_jiffies)) { >> + >> + if (__next_timer_interrupt(base, &expires)) >> + base->next_timer = expires; >> + else >> + expires = now + NEXT_TIMER_MAX_DELTA; > > I believe you can update base->next_timer to now + NEXT_TIMER_MAX_DELTA, > so on any further idle interrupt exit that call tick_nohz_stop_sched_tick(), > we won't get again the overhead of __next_timer_interrupt().
Ah forget that, I was confused. If we do that we actually get the useless timer at now + NEXT_TIMER_MAX_DELTA.
So I think the patch is fine.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com> -- 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/
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