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 A9ED63EBF3F for ; Mon, 23 Feb 2026 13:26:46 +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=1771853206; cv=none; b=ZnTWlZrxsPmeL5E0qRNBgeRyQdru6qNXXLSkOSWmiNy0quwsqt131lVX6/f4EJraq6U46bo/H7SepKsUxxQzieyeHeb1b0R6Z18Xj7or8JIDkg5nEtHVzd89D27nle85CDgAcxWeq4xxRmI6oaORZvJzOvhKH1wFIWZ4vHnpMoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771853206; c=relaxed/simple; bh=v73rkrgbtlx5juHK441/Mun5Ehx25g1i7V299sOMw0I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nhBkxTsMnxiCc9YSJ2SlvSWyZr5Hpb3S2VddW6t8HZ73dUvBzW+aTgtD3M6rEG/lw4Qxzc77wR2Etyzv0JkvlOI+RuGWn2jfQV7zlJu8qqEfSURLJ953hguYprCZQKbNoHnlxrppT/YeAWI2V/ZOjR9CXGJ/XavuA5tMexTNrlY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n/1i9iKL; 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="n/1i9iKL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E48AFC116C6; Mon, 23 Feb 2026 13:26:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771853206; bh=v73rkrgbtlx5juHK441/Mun5Ehx25g1i7V299sOMw0I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n/1i9iKLjsoxy5fgMXFrK4kwJSksVpDV1fYMASMYDBRZzSnSGaKgCEg+p4r18VxX5 kC8ZNf5RaEgRAJ+7CWnGVXoxQH/GnjjyqYDh3h2jC6yu3Q7Sg49NablBEKKUQ7SdLn /F7u1VCL6QDliDdxneXvP/EweTgWb95xA0X2Ii7/yUaf38nZ1tQ3YzQDIZ7rvzKkQF 0eUwFfAuaylBqvAiO0gy9FI1FjrYUNk9U/FUy6x9w5Qz5racu/lMlhahzvNdrKgI+5 VzDygxIbQjpiDeVls4bbQSXnC40VO2DzChBrfLa5tYWuUYwvtKXzaY5+mr0ThcT1jx hcDqz0EAWxQlA== Date: Mon, 23 Feb 2026 14:26:43 +0100 From: Frederic Weisbecker To: Marco Crivellari Cc: linux-kernel@vger.kernel.org, Tejun Heo , Lai Jiangshan , Sebastian Andrzej Siewior , Michal Hocko , Luis Chamberlain Subject: Re: [PATCH v2] umh: replace use of system_unbound_wq with system_dfl_wq Message-ID: References: <20251107160638.328955-1-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: <20251107160638.328955-1-marco.crivellari@suse.com> Le Fri, Nov 07, 2025 at 05:06:38PM +0100, Marco Crivellari a écrit : > Currently if a user enqueues 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. > > This continues the effort to refactor workqueue APIs, which began with > the introduction of new workqueues and a new alloc_workqueue flag in: > > commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") > commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") > > Switch to using system_dfl_wq because system_unbound_wq is going away as > part of a workqueue restructuring. > > Suggested-by: Tejun Heo > Signed-off-by: Marco Crivellari Reviewed-by: Frederic Weisbecker -- Frederic Weisbecker SUSE Labs