Re: [PATCH] workqueue: Restore cpus_allowed mask for sleepingworkqueue rescue threads

From: Tejun Heo
Date: Thu Sep 01 2011 - 20:29:36 EST


Hello,

On Thu, Sep 01, 2011 at 02:36:33PM +0100, Ripduman Sohan wrote:
> Rescuer threads may be migrated (and are bound) to particular CPUs when
> active. However, the allowed_cpus mask is not restored when they return
> to sleep rendering inconsistent the presented and actual set of CPUs the
> process may potentially run on. This patch fixes this oversight by
> recording the allowed_cpus mask for rescuer threads when it enters the
> rescuer_thread() main loop and restoring it every time the thread sleeps.

Hmmm... so, currently, rescuer is left bound to the last cpu it worked
on. Why is this a problem?

Thanks.

--
tejun
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