Re: [PATCH 4/4 V6] workqueue: Allow modifying low level unbound workqueue cpumask

From: Lai Jiangshan
Date: Mon Apr 06 2015 - 21:23:33 EST


On 04/06/2015 11:53 PM, Tejun Heo wrote:
> On Thu, Apr 02, 2015 at 07:14:42PM +0800, Lai Jiangshan wrote:
>> /* make a copy of @attrs and sanitize it */
>> copy_workqueue_attrs(new_attrs, attrs);
>> - cpumask_and(new_attrs->cpumask, new_attrs->cpumask, wq_unbound_global_cpumask);
>> + copy_workqueue_attrs(pwq_attrs, attrs);
>> + cpumask_and(new_attrs->cpumask, new_attrs->cpumask, cpu_possible_mask);
>> + cpumask_and(pwq_attrs->cpumask, pwq_attrs->cpumask, unbound_cpumask);
>
> Hmmm... why do we need to keep track of both cpu_possible_mask and
> unbound_cpumask? Can't we just make unbound_cpumask replace
> cpu_possible_mask for unbound workqueues?
>

I want to save the original user-setting cpumask.

When any time the wq_unbound_global_cpumask is changed,
the new effective cpumask is
the-original-user-setting-cpumask & wq_unbound_global_cpumask
instead of
the-last-effective-cpumask & wq_unbound_global_cpumask.

thanks,
Lai

> Thanks.
>

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