Re: [PATCH] sched,nohz: Change rq->nr_running always using wrappers

From: Frederic Weisbecker
Date: Mon May 12 2014 - 13:56:20 EST


On Fri, May 09, 2014 at 03:00:14AM +0400, Kirill Tkhai wrote:
> Sometimes nr_running may cross 2 but interrupt is not being
> sent to rq's cpu. In this case we don't reenable timer.
> Looks like, this may be a reason of rare unexpected effects,
> if nohz is enabled.
>
> Patch replaces all places of direct changing of nr_running
> and makes add_nr_running() caring about crossing border.
>
> Signed-off-by: Kirill Tkhai <tkhai@xxxxxxxxx>
> CC: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>

Right I had that issue with throttling in my TODO list.

Thanks for fixing that:

Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
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