linux-kernel - Re: [PATCH 1/1] wifi: libertas: WQ_PERCPU added to alloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAAofZF4=UgS+hH_fNry-Sjt8O1wzrEp2x12pcPzh7oPETUZ0-Q@mail.gmail.com>
Date: Mon, 22 Sep 2025 15:32:58 +0200
From: Marco Crivellari <marco.crivellari@...e.com>
To: Johannes Berg <johannes@...solutions.net>
Cc: linux-kernel@...r.kernel.org, linux-wireless@...r.kernel.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>, Francesco Dolcini <francesco.dolcini@...adex.com>, 
	Brian Norris <briannorris@...omium.org>, Sascha Hauer <s.hauer@...gutronix.de>, 
	Kalle Valo <kvalo@...nel.org>, "Dr . David Alan Gilbert" <linux@...blig.org>, Jeff Chen <jeff.chen_1@....com>, 
	Stefan Kerkmann <s.kerkmann@...gutronix.de>
Subject: Re: [PATCH 1/1] wifi: libertas: WQ_PERCPU added to alloc_workqueue users

On Mon, Sep 22, 2025 at 1:33 PM Johannes Berg <johannes@...solutions.net> wrote:
> On Mon, 2025-09-22 at 12:24 +0200, Marco Crivellari wrote:
> >
> > With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
> > any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
> > must now use WQ_PERCPU.
>
> Which I guess forces a decision, and should be kept for a few releases,
> but ... is "keep what it did" really the right decision in all places?
> It seems to me that for instance for libertas here, there really is no
> reason to be CPU bound?

Hello Johannes,

This change has been massively introduced only to make explicit that one
of the two flags must be used (preserving the old behavior), where WQ_UNBOUND
was not present..
Going for each subsystem and checking who really needs to be per-cpu would
have been a future step.

I've already sent a v2 for a few other subsystems changing the old behavior.
I haven't seen per-cpu work, so removing the WQ_PERCPU flag and using
explicitly WQ_UNBOUND instead, is not a problem, also for libertas.

Thank you!

--

Marco Crivellari

L3 Support Engineer, Technology & Product