From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id C83DE7D043 for ; Thu, 24 May 2018 14:36:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935755AbeEXOgU (ORCPT ); Thu, 24 May 2018 10:36:20 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:45499 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935668AbeEXOgS (ORCPT ); Thu, 24 May 2018 10:36:18 -0400 Received: by mail-wr0-f194.google.com with SMTP id w3-v6so3541827wrl.12 for ; Thu, 24 May 2018 07:36:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=IItUpvtsthIeeHOULK4ul0pCR18QTGGFSuZU81iIBwg=; b=EuoXFan1+0bFtsSHbUVNQf14WErhBEyauHlruuaMYu5NC5ZioWjV2nw1PvgA6QJItu zdhiDZ3/i7Y/jI6uNc7JYd1I4I3mE/O2tEZGaSXBeK+fq7USOUkZmASQlGbXewiNnk3i GpyJMzfmuKuCe19+KOysUnDg7JkZUAMXt1cIQtaYCgaadtxGoUeDl5edUrof3WZ6yZi5 T6vmEfSaEWjbCKdt3HkBsfQhV8IauqLWpOTH/OxHMcMEoyy/RkRoPuyKptXS2aRmTCU6 gZrE5yicrPzkfO1EuAZyqn6ef5s6XAGexxKm1Wba02VmR1kjWsgXzAEkV7Vlo5WXsjge y4BA== X-Gm-Message-State: ALKqPwdG15HDiEQAGKp1+6/znJuX85JV5C61dZPz9sILShyhxxsD3Jt+ PIcSZYHGR/Yw4VNfH7R8qqSLVA== X-Google-Smtp-Source: AB8JxZocuL2cj/De8RI67z/b/ygQ/rdq2yiCxjHy46pJBXwkwqNkC4JUm2ROIglt2zScOtifZWyH6Q== X-Received: by 2002:adf:c709:: with SMTP id k9-v6mr7093817wrg.65.1527172577622; Thu, 24 May 2018 07:36:17 -0700 (PDT) Received: from localhost.localdomain ([151.15.207.242]) by smtp.gmail.com with ESMTPSA id o9-v6sm23658585wrn.74.2018.05.24.07.36.16 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 24 May 2018 07:36:16 -0700 (PDT) Date: Thu, 24 May 2018 16:36:14 +0200 From: Juri Lelli To: Waiman Long Cc: Tejun Heo , Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, Mike Galbraith , torvalds@linux-foundation.org, Roman Gushchin Subject: Re: [PATCH v8 3/6] cpuset: Add cpuset.sched.load_balance flag to v2 Message-ID: <20180524143614.GC3948@localhost.localdomain> References: <1526590545-3350-1-git-send-email-longman@redhat.com> <1526590545-3350-4-git-send-email-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1526590545-3350-4-git-send-email-longman@redhat.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 17/05/18 16:55, Waiman Long wrote: [...] > + A parent cgroup cannot distribute all its CPUs to child > + scheduling domain cgroups unless its load balancing flag is > + turned off. > + > + cpuset.sched.load_balance > + A read-write single value file which exists on non-root > + cpuset-enabled cgroups. It is a binary value flag that accepts > + either "0" (off) or a non-zero value (on). This flag is set > + by the parent and is not delegatable. > + > + When it is on, tasks within this cpuset will be load-balanced > + by the kernel scheduler. Tasks will be moved from CPUs with > + high load to other CPUs within the same cpuset with less load > + periodically. > + > + When it is off, there will be no load balancing among CPUs on > + this cgroup. Tasks will stay in the CPUs they are running on > + and will not be moved to other CPUs. > + > + The initial value of this flag is "1". This flag is then > + inherited by child cgroups with cpuset enabled. Its state > + can only be changed on a scheduling domain cgroup with no > + cpuset-enabled children. [...] > + /* > + * On default hierachy, a load balance flag change is only allowed > + * in a scheduling domain with no child cpuset. > + */ > + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) && balance_flag_changed && > + (!is_sched_domain(cs) || css_has_online_children(&cs->css))) { > + err = -EINVAL; > + goto out; > + } The rule is actually - no child cpuset - and it must be a scheduling domain Right? -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html