From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11A89C87FCB for ; Sat, 9 Aug 2025 18:32:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 681E86B009C; Sat, 9 Aug 2025 14:32:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6320E6B009D; Sat, 9 Aug 2025 14:32:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5481F6B009E; Sat, 9 Aug 2025 14:32:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 459146B009C for ; Sat, 9 Aug 2025 14:32:26 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 0D2841601A4 for ; Sat, 9 Aug 2025 18:32:26 +0000 (UTC) X-FDA: 83758064292.03.F3ABD42 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf15.hostedemail.com (Postfix) with ESMTP id 5C240A000D for ; Sat, 9 Aug 2025 18:32:24 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=mFbFXvxg; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf15.hostedemail.com: domain of tj@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=tj@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1754764344; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=nUhNlqQ6VnKeXh2Xn+h8lfDf+kthAcMWidGMDbgJaF8=; b=U5SLdV1wLsrZ2S5w9fN0VCnK2cVaWiIa5JY8lkR7m3Rc61nSYriQuzkbqHjc+fOoeDFQ6z LBqYJBsU0DGI/GnSRtUQxGnG/Nut8hd1QU936H2jNL05L6aGEiwm+L3EbEMS4AWg9rQokt FLouc2O0gQGozlLgd6SwCS3hFglzrFE= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1754764344; a=rsa-sha256; cv=none; b=o9LpXbZMVaBTpWzLMK7S5Z91ys4y5pv9hcgoGulLGNs+yVcEhOXt4KbsXHX6atL4hDdEJG c6HJqwWnjEuL97CvQ3NJLPw+B2kfGYlJmOIsDPlhYXUmePSatwpG7Kdggk79vj7Gn02H9m zPIgcFLaQSbCFg4eDxCV2p9CNJDMdLU= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=mFbFXvxg; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf15.hostedemail.com: domain of tj@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=tj@kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 8E75EA55BCF; Sat, 9 Aug 2025 18:32:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 131AEC4CEE7; Sat, 9 Aug 2025 18:32:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754764343; bh=17cj85UdavT53nLzrHXasrniy7Ghl4dWzlwAnf7kfeo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mFbFXvxgend+sAk55A+p+MqT4U8ca8v3hHJ97OFvQLrSJgmlQALZjnhzjfsQ1O4GE o5sIHr483/YCoKeFiqMn/koKEog2V97LFzZNs9o8SpRoy7iNkwJHNbUWddlqEU6SVD kploU/2KbwgkDpUH0IH9f7BbcYUVNZqVlRA4ZIgXW+sdaga7/QnlaL105oDPYVDGGq w8j9kbLwkwwLr0H0kzzejWGIzpbvVN/KFnib5LPZjwdo6d3snArbJrG5EEq6GeJtn/ DBoFCLHStQ7pD1LCDoBfMK/Al/4wF1dk50oLG2BhApEXkKIeyfRqdWajeWWn3OnoIA qSVy7PMU3WfcA== Date: Sat, 9 Aug 2025 08:32:22 -1000 From: Tejun Heo To: Daniel Sedlak Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Jonathan Corbet , Neal Cardwell , Kuniyuki Iwashima , David Ahern , Andrew Morton , Shakeel Butt , Yosry Ahmed , linux-mm@kvack.org, netdev@vger.kernel.org, Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , cgroups@vger.kernel.org, Michal =?iso-8859-1?Q?Koutn=FD?= , Matyas Hurtik Subject: Re: [PATCH v4] memcg: expose socket memory pressure in a cgroup Message-ID: References: <20250805064429.77876-1-daniel.sedlak@cdn77.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250805064429.77876-1-daniel.sedlak@cdn77.com> X-Rspamd-Queue-Id: 5C240A000D X-Stat-Signature: rdpxghxkkcxnx3apbq4fgj4w8uxake4a X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1754764344-581701 X-HE-Meta: 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 x6rPlqn6 7eZSiDtGPZiaWhthFeyI1XbgK8TBP5kzn0DUMIOrT8CC/KEYKfjKP05u61JZrMNQRFbvdI1y8G5J0I4DOBdcb1ZYe61V9aNV0qGpJAW8cz9B88mY+YPGAl/d/2NS2OuLPnWU0Pmwo15PcYwQyv8bboS0xqa1VNxPnnti2He4sup20ENgClMNzFBBUMHj1+S5VXz72h5xam8pqfCXgzdqwnf+SwSIqLWK1rQdqyDl3sbz7mIwBt7v1a8stoqa69CjJm+bxdMd6EQKF7Qw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, On Tue, Aug 05, 2025 at 08:44:29AM +0200, Daniel Sedlak wrote: > This patch exposes a new file for each cgroup in sysfs which signals > the cgroup socket memory pressure. The file is accessible in > the following path. > > /sys/fs/cgroup/**//memory.net.socket_pressure > > The output value is a cumulative sum of microseconds spent > under pressure for that particular cgroup. I'm not sure the pressure name fits the best when the content is the duration. Note that in the memory.pressure file, the main content is time-averaged percentages which are the "pressure" numbers. Can this be an entry in memory.stat which signifies that it's a duration? net_throttle_us or something like that? Also, as Shakeel already pointed out, this would need to be accumulated hierarchically. The tricky thing is determining how the accumulation should work. Hierarchical summing up is simple and we can use the usual rstat propagation; however, that would deviate from how pressure durations are propagated for .pressure metrics, where each cgroup tracks all / some contention states in its descendants. For simplicity's sake and if the number ends up in memory.stat, I think simple summing up should be fine as long as it's so noted in the documentation. Note that this semantical difference would be another reason to avoid the "pressure" name. Thanks. -- tejun