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 5D7D97D062 for ; Thu, 21 Jun 2018 07:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753938AbeFUH6P convert rfc822-to-8bit (ORCPT ); Thu, 21 Jun 2018 03:58:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47872 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751159AbeFUH6O (ORCPT ); Thu, 21 Jun 2018 03:58:14 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8D84DC057F81; Thu, 21 Jun 2018 07:58:14 +0000 (UTC) Received: from llong.remote.csb (ovpn-116-35.phx2.redhat.com [10.3.116.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 154E91001942; Thu, 21 Jun 2018 07:58:07 +0000 (UTC) Subject: Re: [PATCH v10 2/9] cpuset: Add new v2 cpuset.sched.domain_root flag To: Peter Zijlstra Cc: Tejun Heo , Li Zefan , Johannes Weiner , 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 , Juri Lelli , Patrick Bellasi References: <1529295249-5207-1-git-send-email-longman@redhat.com> <1529295249-5207-3-git-send-email-longman@redhat.com> <20180620142735.GM2494@hirez.programming.kicks-ass.net> From: Waiman Long Organization: Red Hat Message-ID: Date: Thu, 21 Jun 2018 15:58:06 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20180620142735.GM2494@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 21 Jun 2018 07:58:14 +0000 (UTC) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 06/20/2018 10:27 PM, Peter Zijlstra wrote: > On Mon, Jun 18, 2018 at 12:14:01PM +0800, Waiman Long wrote: >> + cpuset.sched.domain_root > Why are we calling this a domain_root and not a partition? A partition can consist of several cgroups in a tree structure. That flag should only be set at the root of a partition. I will change the name to partition_root if you think this name is acceptable. > >> + 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 "1" (on). This flag is set by the parent >> + and is not delegatable. > You still haven't answered: > , > https://lkml.kernel.org/r/20180531094943.GG12180@hirez.programming.kicks-ass.net > > the question stands. I am sorry to miss your question. Turning on domain_root will affects the cpu mapping in the parent. That is why it cannot be set by the child as a child is not supposed to be able to affect the parent. As for the inconsistency between the real root and the container root, this is true for almost all the controllers. So it is a generic problem. One possible solution is to create a kind a pseudo root cgroup for the container that looks and feels like a real root. But is there really a need to do that? Cheers, Longman -- 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