linux-kernel - Re: [RFC PATCH 0/2] workqueue: Introduce PF_WQ_RESCUE

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Message-Id: <20230801105301.952042-1-atomlin@atomlin.com>
Date:   Tue,  1 Aug 2023 11:53:01 +0100
From:   Aaron Tomlin <atomlin@...mlin.com>
To:     tj@...nel.org
Cc:     peterz@...radead.org, atomlin@...mlin.com, jiangshanlai@...il.com,
        linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH 0/2] workqueue: Introduce PF_WQ_RESCUE_WORKER

> You really shouldn't be setting affinities on kworkers manually. There's
> no way of knowing which kworker is going to execute which workqueue.
> Please use the attributes API and sysfs interface to modify per-workqueue
> worker attributes. If that's not sufficient and you need finer grained
> control, the right thing to do is using kthread_worker which gives you a
> dedicated kthread that you can manipulate as appropriate.

Hi Tejun,

I completely agree. Each kworker has PF_NO_SETAFFINITY applied anyway.
If I understand correctly, only an unbound kworker can have their CPU
affinity modified via sysfs. The objective of this series was to easily
identify a rescuer kworker from user-mode.


Kind regards,
-- 
Aaron Tomlin