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 94A9D2FE397; Thu, 17 Jul 2025 17:05:16 +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=1752771917; cv=none; b=jGqwWuegviJLOgiyaquPd7Pu8FpGS7MnQSy5JyLU6b9Us9jLmufX0Qm08QhcqjrfoQyoPfzR3jslHlgQ+cIagbsLukJif82y9fnRa6ak2uejxumYfu4R5fzikMm0htAUbZ9/NbkafO467fszVdH2fBouURhw7+ZSmuYS3ZdFQKQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752771917; c=relaxed/simple; bh=f4TBundVVp2x6JyWmytFqL4rDtzsnoQsuVW6B2mEUH4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=k3c0sxSH0KMJ4YyIfz1gQPPhEWUislv6sHPjaFiUbSjGPsdevurvfiVDxP2e3uvZ+tXwyyimu2MqpmZaMR8TbLZSLVQ+dM3z88aS9ZlWHou7CRXC3SK0bpHtbnzsfIJotGsQGTOUCjYc1Gf7kquTnnJ8Z9u7xOocv78BnOQQ118= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jOIjZBB7; 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="jOIjZBB7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFAC8C4CEF8; Thu, 17 Jul 2025 17:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752771916; bh=f4TBundVVp2x6JyWmytFqL4rDtzsnoQsuVW6B2mEUH4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jOIjZBB7nU8CwNhHDFRA80VBsXfOlimaTqZPoUiEVSQK2yXapmorp0V7HzIT5/a5p 0PfGhnsSg160RD1rQlErlJCl651qwBRqIgQHTld3BlWXHS9WTdWrfQ8KVAE+Nu9wYV vB4K/g3iEn+glYyU7Q0T+UA9ZpwIYH03FQEYjc9UBM7zlqbNwSBUrZg+yCk6GR5QuW X2yp7X3wu9FC09muDTNBc/kK0PxQ1bCrv9LGRjrzuG+aH/L7v8ztx31UqHbBup2j/M 1/xM2ivZisfItTo9XP8fOVDGF9LHKlDi4JlpXb3BTbJorKz6vzJoxOa+rVmiZ6/763 CyuntPEFZLUUA== Date: Thu, 17 Jul 2025 07:05:14 -1000 From: Tejun Heo To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: Tiffany Yang , linux-kernel@vger.kernel.org, John Stultz , Thomas Gleixner , Stephen Boyd , Anna-Maria Behnsen , Frederic Weisbecker , Johannes Weiner , "Rafael J. Wysocki" , Pavel Machek , Roman Gushchin , Chen Ridong , kernel-team@android.com, Jonathan Corbet , cgroups@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [RFC PATCH v2] cgroup: Track time in cgroup v2 freezer Message-ID: References: <20250714050008.2167786-2-ynaffit@google.com> <5rm53pnhpdeqljxqywh26gffh6vlyb5j5s6pzxhv52odhkl4fm@o6p7daoponsn> 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: <5rm53pnhpdeqljxqywh26gffh6vlyb5j5s6pzxhv52odhkl4fm@o6p7daoponsn> Hello, On Thu, Jul 17, 2025 at 02:56:13PM +0200, Michal Koutný wrote: ... > > + cgroup.freeze.stat > > With the given implementation (and use scenario), this'd better exposed > in > cgroup.freeze.stat.local > > I grok the hierarchical summing would make little sense and it'd make > implementaion more complex. With that I'm thinking about formulation: > > Cumulative time that cgroup has spent between freezing and > thawing, regardless of whether by self or ancestor cgroups. NB > (not) reaching "frozen" state is not accounted here. I wonder what hierarchical summing would look like for this. It's absolute time interval measurement and I'm not sure whether summing up the descendants' durations is the best way to go about it. ie. Should it be the total duration any of the descendants are freezing or should it be sum of the freezing durations of all descendants? Thanks. -- tejun