Re: [PATCH v5 07/12] sched: test the cpu's capacity in wake affine

From: Peter Zijlstra
Date: Wed Sep 10 2014 - 10:19:20 EST


On Tue, Aug 26, 2014 at 01:06:50PM +0200, Vincent Guittot wrote:
> Currently the task always wakes affine on this_cpu if the latter is idle.
> Before waking up the task on this_cpu, we check that this_cpu capacity is not
> significantly reduced because of RT tasks or irq activity.
>
> Use case where the number of irq and/or the time spent under irq is important
> will take benefit of this because the task that is woken up by irq or softirq
> will not use the same CPU than irq (and softirq) but a idle one.
>
> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>

Rik, you've been 'fighting' wake_affine, any objections?
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