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 D13EF239562; Wed, 3 Sep 2025 16:53:37 +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=1756918417; cv=none; b=sg4d4tXoSzRPz0grXfgdK2YK3L8KOJNR9ATDlMWCieqaRNvq/Sp8Z6M4GZk/xmM5xMIWQ/F67TGjLuwlXpSgZrBWL6vyDzmu6uxpYsFyvLzS/6AeYH86+PPVXelq1CjU0Y07wndssJpWBwFkhkD3aj6uPx2Sw4iGieS9ORutIDU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756918417; c=relaxed/simple; bh=F4UICW0+whfKFfSpa5zuMSqm0DVzQoL0Yu1hWvbm1jM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sJDFY5NIBoOp4y64Pt+EHate6xw2YZ0BkniDivJPiyxv6ge2Rm9frioGg3ylAGUVSzUNwrxIz6NTzoIWqBkuREiEEZNwnF5tI/7qo4tBtTs7hcIqW+WP1nGXLYksSHbfHVkHWk9VT+47J8WhRTLBBTT0EIHLEhDlGaohnrKPnRY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p3y5MkkL; 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="p3y5MkkL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21044C4CEF0; Wed, 3 Sep 2025 16:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756918417; bh=F4UICW0+whfKFfSpa5zuMSqm0DVzQoL0Yu1hWvbm1jM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p3y5MkkLnE1mJfxy2umMQ4UT5u3eIR8qoMXeihN4NpF2J37VcLFMWacqokO5TFeAS 9Wi/b69ViPdBrlb74hOWkll8y+zwNz1HVanAy9RRhztpPBrMfAilZqCBUFlGTK7BvG YxqoP1vaBmR9FdGQNwM/wN+M3ykK7BvD2VxBE4I+LDzadS9hJXcBN3AXPYDNjgHKJo amFcclv20hYnMgA0zy+5kAsB1gRnyaD6s/TrhLnz7sE6hrYlHlx5DPQlqtV1LkOp/a atmxDEX4USr0yRpuCZmPJ4X+yu3t60cXb+yxRzwgdQif78cjqcdjEeNrlkboXJOrV6 suQIPhv5jCSxQ== Date: Wed, 3 Sep 2025 06:53:36 -1000 From: Tejun Heo To: Yi Tao Cc: hannes@cmpxchg.org, mkoutny@suse.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cgroup: replace global percpu_rwsem with signal_struct->group_rwsem when writing cgroup.procs/threads Message-ID: References: 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: Hello, On Wed, Sep 03, 2025 at 07:11:07PM +0800, Yi Tao wrote: > As computer hardware advances, modern systems are typically equipped > with many CPU cores and large amounts of memory, enabling the deployment > of numerous applications. On such systems, container creation and > deletion become frequent operations, making cgroup process migration no > longer a cold path. This leads to noticeable contention with common > process operations such as fork, exec, and exit. If you use CLONE_INTO_CGROUP, cgroup migration doesn't just become cold. It disappears completely and CLONE_INTO_CGROUP doesn't need any global locks from cgroup side. Are there reasons why you can't use CLONE_INTO_CGROUP? Thanks. -- tejun