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 X-Spam-Level: X-Spam-Status: No, score=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C260BC4743E for ; Tue, 8 Jun 2021 16:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC3D361184 for ; Tue, 8 Jun 2021 16:26:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233804AbhFHQ22 (ORCPT ); Tue, 8 Jun 2021 12:28:28 -0400 Received: from mail-yb1-f173.google.com ([209.85.219.173]:45943 "EHLO mail-yb1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233485AbhFHQ2Z (ORCPT ); Tue, 8 Jun 2021 12:28:25 -0400 Received: by mail-yb1-f173.google.com with SMTP id g38so30985808ybi.12 for ; Tue, 08 Jun 2021 09:26:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=O9BYezu8gyZabw4yWCqgrj5D/dzmRPqg3cqOBnuX70I=; b=JFQV+NEkpW/iFhrOOSAEJdSvL4Y5t7uoDY1dd51Y2Duhk5IpfAeqhuOyRWPFleGd3j IYdDjObTU/mSwgFZLLbQl5DFxzATFnERzNKUj5O4DVbW7GoQzRu3HVFLrA6eE932UFqa TUBINtgBShb/FCjRoTrYIdj2+wQRXbb2T1VZ52hbLSQRcCbHE42KncKpaSAw32jsGP5E aOHoGGn9J8Esk/WJ6zRNYgghsabPfwjmjUR7H7m9bfTjOaWn1kBnCbrIJrYVMBeHab7V 9z39z1pHc3ZsyC7nRCPnIz4iOwdfrAki0j7U0Jb8FcXcaGkp0//wtiz90eUBg7r+88WM BlZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=O9BYezu8gyZabw4yWCqgrj5D/dzmRPqg3cqOBnuX70I=; b=WKQFGlbj5lfUkJ88gYU31vwREiSl5w4QqGx4U9ruIfHSx05CayxLewPZskJfumzBe8 ga7iTcKMUH2PYV3I39KEezHTElCFRD0SpNGyA5ERtY+iVUk/wuIZXqHjDG3lEFYqH9JK fhot3QFzMxpOWPeQsUBxfMcFqRLhicjB3GzQWIHKUToZddxD6V6ymGsm/MnDACBFwaCl myB3bUrvIKe3xTHPbKgSR7JayMKIzMDpP/DTZQZbKXV39PLM9jBmDtVWOB+s49lM8IOa 8TNgv7tRLm88TDEYdIu38vCLJht6SDzsfmoU57seiJFdm2W/Br2E/AeoGl2x9sZPTM+I SEaw== X-Gm-Message-State: AOAM532GLtjH2ut+uZ/TCSkR96Ut+pU6PdRLplRUAGxGk9nkmmVLrq6Y gewGV6psrkmQ0TOD7CVMARmHfo9chDyFga66lJN2Wg== X-Google-Smtp-Source: ABdhPJy/90mDe1H2hifctB9B/7ALX5JPz820xu2hHqF2Ww069zzxmnIKlkaoYn4bNVvu6YINVAbfCT1TVBOcLPHP9dE= X-Received: by 2002:a25:ade3:: with SMTP id d35mr34223802ybe.190.1623169519031; Tue, 08 Jun 2021 09:25:19 -0700 (PDT) MIME-Version: 1.0 References: <20210524195339.1233449-1-surenb@google.com> In-Reply-To: From: Suren Baghdasaryan Date: Tue, 8 Jun 2021 09:25:08 -0700 Message-ID: Subject: Re: [PATCH v3 1/1] cgroup: make per-cgroup pressure stall tracking configurable To: Johannes Weiner Cc: Tejun Heo , Zefan Li , Ingo Molnar , Peter Zijlstra , Shakeel Butt , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Benjamin Segall , Mel Gorman , Minchan Kim , Jonathan Corbet , Daniel Bristot de Oliveira , "Paul E . McKenney" , Randy Dunlap , Andrew Morton , Thomas Gleixner , macro@orcam.me.uk, Viresh Kumar , Mike Kravetz , linux-doc@vger.kernel.org, LKML , cgroups mailinglist , kernel-team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, May 25, 2021 at 6:00 AM Johannes Weiner wrote: > > On Mon, May 24, 2021 at 12:53:39PM -0700, Suren Baghdasaryan wrote: > > PSI accounts stalls for each cgroup separately and aggregates it at each > > level of the hierarchy. This causes additional overhead with psi_avgs_work > > being called for each cgroup in the hierarchy. psi_avgs_work has been > > highly optimized, however on systems with large number of cgroups the > > overhead becomes noticeable. > > Systems which use PSI only at the system level could avoid this overhead > > if PSI can be configured to skip per-cgroup stall accounting. > > Add "cgroup_disable=pressure" kernel command-line option to allow > > requesting system-wide only pressure stall accounting. When set, it > > keeps system-wide accounting under /proc/pressure/ but skips accounting > > for individual cgroups and does not expose PSI nodes in cgroup hierarchy. > > > > Signed-off-by: Suren Baghdasaryan > > Acked-by: Johannes Weiner Gentle ping for cgroup folks to please take a look at the cgroup interface part.