From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BBA1B3B14A4; Tue, 15 Sep 2026 17:45:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789494321; cv=none; b=siE83XPDn95NE+voNqSgK1lnSDj1eB1aek8+gcb8CPHXbB5lLrjA1j1LRsXo/ek+3GR45LBmMvbvXhtPQfQMV/MGX6K4+tWKsxAMsz9w9uUVP8jKWBZSWjNN9NH6NetDUr3zncWoxfoiHq3LTkO5Sed87YD6B6BldUI+5FS8VlI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789494321; c=relaxed/simple; bh=8VmRu6URDVDFRDSJizS04tRvucLtnKbX0HNSV/eiELo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jKDgnM/8hDawVb49V3JMdb8LKJsd5maWLh8zSco34BFCFwn8pnHf9hjx2FFBBbLqdKzm0A9G7jb6FymzvUD2L0wIpwgUgKwhK47sN/nE9CDxnLWVstNMBPlHOs41u6yH/1y6rOeblg9PX9pOPpONC5Ub2WA0+r+RJbbouIaifoE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M6zO4m1T; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M6zO4m1T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15A411F000FF; Tue, 15 Sep 2026 17:45:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789494318; bh=ZzqTBEUN5ZkT4CrwyeKMEtf7VfDqQJ0NB6PSY7rcRwY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=M6zO4m1TC11BSsF0irVcawKtSRQogofIydoXxhQxk4qLG09/KuXy7jGWTVWv22DR6 BhAVjHT7TrcnYBJ4iCY8uU6QFjHoz48wc4JE2eWe9Mti6hH+mZAUBW/5qYi4k3LG7f GywmK+efzf7eEdolU3fq+ciWaGt5eqajGRLKP/jFu27osgtz9XesA3bc2Lu9IdV5q6 AchP2rtGdwRT4zdtMcncsPAKQXkxOzp4GcWL3phYnhdVv4f+abfTFI9FZouw2KjWn8 SmYeLwJ0qXWdXYFsvxuBCeetvAYH6PDovDolRIwTSBUeNEpNmo2/Fj8nKTfele3upd BXsChq77n4pQQ== Date: Tue, 15 Sep 2026 07:45:17 -1000 From: Tejun Heo To: Junnan Zhang Cc: cgroups@vger.kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, mkoutny@suse.com, ridong.chen@linux.dev, sunshx@chinatelecom.cn Subject: Re: [PATCH v3] cgroup: avoid flushing global workqueue in cgroup1_pidlist_destroy_all Message-ID: References: <20260910061610.91209-1-zhangjn_dev@163.com> <20260915124010.18927-1-zhangjn_dev@163.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=us-ascii Content-Disposition: inline In-Reply-To: <20260915124010.18927-1-zhangjn_dev@163.com> On Tue, Sep 15, 2026 at 08:40:10PM +0800, Junnan Zhang wrote: ... > To be upfront: I still have not reproduced the full 120s hang in the > lab; the backlog and per-work latency I can build here remain well > below the production node's. But the unpatched latency grows with > exactly the two factors that were larger in production, while the > patched latency is insensitive to them -- on an otherwise idle > machine, with no competing workqueue items, no worker-creation stalls > and no CPU contention. That's a larger than two orders of magnitude gap. There likely were other, a lot more important, factors. Thanks. -- tejun