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 DFDCD32C30F; Mon, 18 Aug 2025 17:08:40 +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=1755536921; cv=none; b=PG6uHU0fe/Lhd/lLW7UZG0fgpo14QMyGolgZGiJXqST41jfrLGe5z4XmLZk5ZCXjXHm9QJ/oc878xUql7Z+rcymcpOdo5nDbTUpXjNWX3qU0Or8Vjf37IAw65AYL09MG79gwag4mpiBseaesplQZwlDmssJOVvGse2OQm+MxWHw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755536921; c=relaxed/simple; bh=64CcmkGtdUxeHQ1pBgSUaPFesNmD3+o91YK6wmGkYJE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dsbP+A46tjUOQ+Mwa3vrO493QgnEOOLXC7JE/2e/HXu2qhlzR8rFO+uPauDaCFENgsEDL+Cr/Te2VWgnGfYkSrVkNXpmfxI+nq8sGiWRXN284Tz/VwcE/Ff8sFbtBKeCwUEgu1qMp2/QOPhBkzOGevSouAMwsVrKYxV2apC0trQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cB3fT4AE; 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="cB3fT4AE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F574C4CEEB; Mon, 18 Aug 2025 17:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755536920; bh=64CcmkGtdUxeHQ1pBgSUaPFesNmD3+o91YK6wmGkYJE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cB3fT4AEF3Up/BvqosBGRperiBFtvAvgJ1bC3UdhNTb65WHq0vzhH1S6kulu+uLcl w0n9UZWXiIxmL69PScnQZNRdyl5jhIum4rRpXKCqxhxYP/L1wfCyy+DUlGGYNzkOHR 7mSVhgW7Z2Kp3TOPYWYMN0wL/gHPbjN/bT6WANkHx06KnCP9Sg+vY3ULXVcMWaxae5 rUCRKCXmWKOSIRqrsIFQXAO3C6ge8712FlH2b41Utl/78x/NB4vBhuJb6DA/p/Lbob Yb7M4jEqFmIbEvZXr4xKvSJr1AdFw8Ju4tZXygiEUn3Tm8EhbWT4l1sRGc/eVmt42h r4YO2Hl7N9JiQ== Date: Mon, 18 Aug 2025 07:08:39 -1000 From: Tejun Heo To: Chen Ridong Cc: hannes@cmpxchg.org, mkoutny@suse.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, lujialin4@huawei.com, chenridong@huawei.com, hdanton@sina.com, gaoyingjie@uniontech.com Subject: Re: [PATCH v5] cgroup: split cgroup_destroy_wq into 3 workqueues Message-ID: References: <20250818034315.1303955-1-chenridong@huaweicloud.com> <20250818061435.1304516-1-chenridong@huaweicloud.com> Precedence: bulk X-Mailing-List: cgroups@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: <20250818061435.1304516-1-chenridong@huaweicloud.com> Hello, On Mon, Aug 18, 2025 at 06:14:35AM +0000, Chen Ridong wrote: ... > + * Rationale for using separate workqueues: > + * The cgroup root free work may depend on completion of other css offline > + * operations. If all tasks were enqueued to a single workqueue, this could > + * create a deadlock scenario where: > + * - Free work waits for other css offline work to complete. > + * - But other css offline work is queued after free work in the same queue. Can you please refer to the concrete example too? Thanks. -- tejun