From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 5E3FA2459E1 for ; Tue, 29 Sep 2026 13:51:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790689879; cv=none; b=az1IXqkZgOBKJkijh95Ai/BBCj+YuS0wUEdWYezzma6GGs0guR5QoOEn6HOkkyA5fJFPqcemuSNtsGCawKFu8ftqLnppxfHW4fBnXxy3Z70FoeUuSl1GbHOB5VHyW2nblkKymD7AyWcQjVCXeCIuD8fvOlN+9M/kWp1UqJ/lvMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790689879; c=relaxed/simple; bh=TYF29B8WG+iQvzzIrANYNP3KFNzNJZq/Q0IdpOUlnts=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DxRgQyHhsPQ04tI5ctGOvyMLfu8UVzMJ8qtWsn5hkvB5qbFBz+numDDFeINUHcU1LZNjvL/0t3TjiEYlgRUxcKFKZqwhhi5tdN2M4vh9FixWWAQteX0ZxKsPIzI/GKriBjS2XF5/MZUYunUs0kaFnvh7rjtyTMwUk/+NKv68erE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=aGLFW+Mp; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="aGLFW+Mp" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=zFuTF/YqpoHkqpDwBGXiRlU4Ww8ZRrUwfgBzvlLnBEY=; b=aGLFW+Mpk9muBwNh+BGdSwObeZ 8/eDBDvf31XQ4dXmKNxpSP4A30wYSz93OcsmK78OtLFxixEO0/DuKqEIVJ53XlrXAJ8VGILSMwqGu IfX/Yq4LGsXrepS7XbBRP67Z4+uM5NhGqmPX4MJAXkZ5RWFYJbFEfbh0flPOMcJFd2wq+ylQNz8aj ivRlRPfNExkzQUQcGRqXtqphQr/5PV1mZvvpTG/ir3bSQjnNG451f+VhsYTugW9o6t4isQ34KaehV 7d2kr2Bmrjarvdkfuity+15oxTgCuDtIOxQjzdY2LyAhqnpkKEyUrNqjK0UquN5GqW9/ZIgQVjFqh c/qvnRMg==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1xBYEi-008SFT-0J; Tue, 29 Sep 2026 13:51:12 +0000 Date: Tue, 29 Sep 2026 06:51:07 -0700 From: Breno Leitao To: Tejun Heo Cc: Lai Jiangshan , Marco Crivellari , linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH wq/for-7.4 v2 3/3] workqueue: add a percpu_concurrency_managed workqueue attribute Message-ID: References: <20260925-wq_final-v2-0-860ee052169e@debian.org> <20260925-wq_final-v2-3-860ee052169e@debian.org> <1bcd7a71f382de147d7e26ee14f00ac7@kernel.org> 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=us-ascii Content-Disposition: inline In-Reply-To: <1bcd7a71f382de147d7e26ee14f00ac7@kernel.org> X-Debian-User: leitao Hello Tejun, On Mon, Sep 28, 2026 at 11:31:11AM -1000, Tejun Heo wrote: > On Fri, Sep 25, 2026 at 06:09:52AM -0700, Breno Leitao wrote: > > Introduce percpu_concurrency_managed, similar to the discussion in [1], > > and use it when deciding to do concurrency management, instead of > > relying on WQ_PERCPU (the only WQ type that does CM as of now). > > Once PERCPU is its own scope, the scope picks the backend, and concurrency > management and the per-cpu max_active follow from that. Opting out of > concurrency management on the per-cpu pools is what WQ_CPU_INTENSIVE already > does, and I don't see a need to change that at runtime. How about dropping > this patch for now? Ack, I will continue to decide about concurrency management by looking at the affinity scope other than a new knob. Thanks for the review, --breno