linux-kernel - Re: [PATCH v2 1/3] drm/i915: replace use of system_unbound_wq with system_dfl

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Message-ID: <vzwd2i6wn75oxn5e34xwky74ezpjjosyhx5kvcvwvywhohzegq@xfhhlcdei6it>
Date: Tue, 4 Nov 2025 07:30:52 +0000
From: Krzysztof Karas <krzysztof.karas@...el.com>
To: Marco Crivellari <marco.crivellari@...e.com>
CC: <linux-kernel@...r.kernel.org>, <intel-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>, Jani Nikula <jani.nikula@...ux.intel.com>, Joonas Lahtinen
	<joonas.lahtinen@...ux.intel.com>, Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Tvrtko Ursulin <tursulin@...ulin.net>, David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>
Subject: Re: [PATCH v2 1/3] drm/i915: replace use of system_unbound_wq with
 system_dfl_wq

Hi Marco,

Thanks for addressing my previous comments so quickly!
I have one more remark to the wording.

> Currently if a user enqueue a work item using schedule_delayed_work() the
> used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
> WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
> schedule_work() that is using system_wq and queue_work(), that makes use
> again of WORK_CPU_UNBOUND.
> 
> This lack of consistency cannot be addressed without refactoring the API.
> 
> system_unbound_wq should be the default workqueue so as not to enforce
> locality constraints for random work whenever it's not required.
> 
> The above change to the Workqueue API has been introduced by:
> 
> commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")
I appreciate you adding the references to existing change, but
I'd rewrite above two lines to:

"This patch continues the effort to refactor worqueue APIs,
which has begun with the change introducing new workqueues:
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag").".

Otherwise, the sentence "The above change to the Workqueue API
has been introduced by" to me suggests that you are trying to
re-introduce or fix something that already exists in the kernel.

-- 
Best Regards,
Krzysztof