linux-kernel - Re: [PATCH 2/4] drm/amdgpu: replace use of system_wq with system_percpu

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Message-ID: <CAAofZF5pSB-kJVr_PJbo_845VbpaB1Fbf+yeA74sWOU_vXfypQ@mail.gmail.com>
Date: Fri, 31 Oct 2025 10:01:21 +0100
From: Marco Crivellari <marco.crivellari@...e.com>
To: Christian König <christian.koenig@....com>
Cc: linux-kernel@...r.kernel.org, amd-gfx@...ts.freedesktop.org, 
	dri-devel@...ts.freedesktop.org, Tejun Heo <tj@...nel.org>, 
	Lai Jiangshan <jiangshanlai@...il.com>, Frederic Weisbecker <frederic@...nel.org>, 
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>, Michal Hocko <mhocko@...e.com>, 
	Alex Deucher <alexander.deucher@....com>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>
Subject: Re: [PATCH 2/4] drm/amdgpu: replace use of system_wq with system_percpu_wq

On Thu, Oct 30, 2025 at 6:10 PM Christian König
<christian.koenig@....com> wrote:
>[...]
> In this particular use case we actually don't want the percpu wq.
>
> This can execute on any CPU except for the current one.
>
> Regards,
> Christian.
>
> >  exit:
> >       if (amdgpu_sriov_vf(adev)) {
>

Hi Christian,

like for the unbound workqueue also the system_percpu_wq is just a
rename for system_wq.
Technically I changed the workqueue because we added in the code two wq:
- system_percpu_wq
- system_dfl_wq

You can see the commits mentioned in the cover letter, shared also below:

- commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
- commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

So basically the behavior is the same.

But if it would be beneficial to have an unbound wq, I can send the v2
with the change!
We did so also for other subsystems.

Thanks!



--

Marco Crivellari

L3 Support Engineer, Technology & Product