Re: [PATCH 2/4] drm/amdgpu: replace use of system_wq with system_percpu_wq

From: Christian König
Date: Mon Nov 03 2025 - 10:57:08 EST




On 10/31/25 10:01, Marco Crivellari wrote:
> On Thu, Oct 30, 2025 at 6:10 PM Christian König
> <christian.koenig@xxxxxxx> 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!

Please do so. The purpose of offloading that into a work item is to execute it on a different CPU.

I wasn't aware that the system_wq was CPU bound at all.

Thanks to taking care of that,
Christian.

> We did so also for other subsystems.
>
> Thanks!
>
>
>
> --
>
> Marco Crivellari
>
> L3 Support Engineer, Technology & Product