From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D22C527FD5B for ; Tue, 6 May 2025 12:55:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746536117; cv=none; b=lTFX4lu7d6/nuAycn1Z+7pnwFDIygjAAN/sTT2jjSvIsM2GLetOIHoHC0Uot92dhT5Moo4rCigaQ24rsrcGnGD34lwfubgDZKaDbn50iGWBYNcYPW5ljlAVSsXQMfaQnS7BaAyun3HPhpwPJUnxC4oy7KUj4UwcSsS5f8JttTgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746536117; c=relaxed/simple; bh=vOfAL/qzO/ycGuh7I27Qepc+xDNQHpOz1aWR0a5fy3g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=peEoiMk000waU6XIWI9cEf+przv8U4RUoQDsJF3zYCc+TQfjx4KjiNnZw09K4OvChwbw06SjfKfGvJut84WCVuhKvoUqnjXzgigDgD8CGjTMuKf+Nyf24ePwu+GFXqWf3APpTSR1Jz8OZwpHin8UjbHl+jIDO/p1kGZfvtLsDiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qplgLNWU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qplgLNWU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E54AEC4CEE4; Tue, 6 May 2025 12:55:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746536117; bh=vOfAL/qzO/ycGuh7I27Qepc+xDNQHpOz1aWR0a5fy3g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qplgLNWU3kxHo+hpTvNfQtXL8dlXJWYGVMI0pKZakDrjgsPGg8XXS13qLJW8uZESF asawnBC688YueGJdtlhVY9gK9K3vH5O5jTG0+Hk6MoVOa/ytJ3AF0K0EP2N2lvi50y 0OubBsFvSS8MxBEejedOemQseQ8ukQY8C6e/9rAIHjQCL/0bFT+XnMI43YiQKx6+wT ZnjBqWiIWp4zPhbSp1QItSJoY+vPD8eJ25x1shAkidlMbqBuD51re50eU2ojNkonfH cOfidLkNm6WIrv8/II5uLb/ULfp9OuywupFKDGFnedvYPAS08LMFR9Br7ehP1D7HcW Myy0ZNDqtqNBw== Date: Tue, 6 May 2025 14:55:14 +0200 From: Frederic Weisbecker To: Marco Crivellari Cc: Tejun Heo , linux-kernel@vger.kernel.org, Lai Jiangshan , Thomas Gleixner , Sebastian Andrzej Siewior Subject: Re: [PATCH 0/4] Workqueue: rename system workqueue and add WQ_PERCPU Message-ID: References: <20250503082834.49413-1-marco.crivellari@suse.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Le Tue, May 06, 2025 at 12:10:18PM +0200, Marco Crivellari a écrit : > Hi, > > > Can you please make a summary of the discussion here? Referring to old > > thread is useful but it'd be nice to have the rationales laid out in the > > patchset - why this is desirable, what is the transition plan and what are > > the rationales for it? Also, please include a short summary in the patches. > > Sure, thanks for the advice. > > > Let's keep the old names for a release or two and trigger printk_once() > > warnings about the renames. These are pretty widely used, so I think it > > warrants a bit of extra effort. > > Good, sounds fine. > But I don't understand where printk_once() should be placed. > Can you give me some further guidance? So one possibility to achieve this is to not do a rename of system_wq to system_percpu_wq but eventually keep system_wq around and create the new system_percpu_wq. Convert all current users of system_wq to system_percpu_wq and warn from queue_work() when system_wq is used. I would personally prefer that we use WARN_ON_ONCE() so that this really gets noticed. Tejun what do you think? Thanks. -- Frederic Weisbecker SUSE Labs