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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8B15CC49EAB for ; Tue, 8 Jun 2021 19:19:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7242A613D0 for ; Tue, 8 Jun 2021 19:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238995AbhFHTUt (ORCPT ); Tue, 8 Jun 2021 15:20:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236136AbhFHTIz (ORCPT ); Tue, 8 Jun 2021 15:08:55 -0400 Received: from mail-qk1-x735.google.com (mail-qk1-x735.google.com [IPv6:2607:f8b0:4864:20::735]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91230C061149; Tue, 8 Jun 2021 12:01:07 -0700 (PDT) Received: by mail-qk1-x735.google.com with SMTP id u30so21264504qke.7; Tue, 08 Jun 2021 12:01:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=tyj1ti03dIMK1ozRhjYuzmAR0/ZNP3Nds6icyKCHFlQ=; b=aquonKpFpgW+meXELKk7PeP2BVEA64UDJBDwLTmHutu10dBUUYxGnxY/IIjgPhz1tZ YvU/9lSBFDD5nca8ydmknI4+DI0UMUvW5frN06/dfKwmSQYvoUBddPuKk+wCm2Fut1aS s/BhxnBO6tXrWGLaNJzeglvRX7Yf4f+cIkry6stGacZIGLeqgQUXTjKsK9tXFlnK0fh4 dT4pcL2b5cHyY3b9OZtOlT2P12Uk2v3gfGx0NqxpvOMc4osp/8IdJLF8ukCPfbJQN1ph w9rpiWsMk6qxYup0HnG0vl4Y5b1frD11laPoGhDn7EIXl4m67RBRitzQURMiI2Bvkh29 E0iA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=tyj1ti03dIMK1ozRhjYuzmAR0/ZNP3Nds6icyKCHFlQ=; b=MGo6/dqNZ/OwgsZnzVBDYHlt1jxBZr7M+AYEzn5aedxWw8xD2TAWz5OpwHktcyL5Cg MJ6BkvKatcvGx7VjOjiv3fU1CVeww70KZ19xXByWHQp2Trqbpx/2aBuiGUxqkYXeuy0N bV3ZSfhZNRJkcaRa/gsddETzJrHW4PkdAJQ2t9nQke5eUB++jgAxJlAomxI0E+EYODsk 7K4zSQOZmkh+qMYkBGfvOpBCfe4VWwlY40f49WHCTnkbqz20u/Te6rz/6AvZuM9DL0DM tCHRTPq30Uw5zpBR/ch3lu54XBhrBzDkBDhecqHM0k/6O+M6Vsp6ztzI7eQs3qudMqLh FIhw== X-Gm-Message-State: AOAM532fgbCJfEwtTV4fler9ri6mwrecsWIEbKYyIanZZpCZk8YQYmbE oSGRuUjMMDHSOyelDg+LhRg= X-Google-Smtp-Source: ABdhPJwipmZzBXCdpz+kuF92MD2gopIukii17l8upDYLoD+HlPR/OmSTF++k04VMS7IBUeHkV4Vokw== X-Received: by 2002:a37:e215:: with SMTP id g21mr1954570qki.37.1623178866256; Tue, 08 Jun 2021 12:01:06 -0700 (PDT) Received: from localhost ([199.192.137.73]) by smtp.gmail.com with ESMTPSA id k13sm12519911qki.24.2021.06.08.12.01.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Jun 2021 12:01:05 -0700 (PDT) Sender: Tejun Heo Date: Tue, 8 Jun 2021 15:01:05 -0400 From: Tejun Heo To: Suren Baghdasaryan Cc: hannes@cmpxchg.org, lizefan.x@bytedance.com, mingo@redhat.com, peterz@infradead.org, shakeelb@google.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, minchan@kernel.org, corbet@lwn.net, bristot@redhat.com, paulmck@kernel.org, rdunlap@infradead.org, akpm@linux-foundation.org, tglx@linutronix.de, macro@orcam.me.uk, viresh.kumar@linaro.org, mike.kravetz@oracle.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3 1/1] cgroup: make per-cgroup pressure stall tracking configurable Message-ID: References: <20210524195339.1233449-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210524195339.1233449-1-surenb@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Applied to cgroup/for-5.14. Thanks. -- tejun