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=-2.4 required=3.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,USER_AGENT_MUTT autolearn=ham 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 9E462ECDFBB for ; Fri, 20 Jul 2018 11:46:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5798C206B7 for ; Fri, 20 Jul 2018 11:46:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SoTwqdmE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5798C206B7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729922AbeGTMdo (ORCPT ); Fri, 20 Jul 2018 08:33:44 -0400 Received: from mail-yb0-f196.google.com ([209.85.213.196]:36361 "EHLO mail-yb0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727408AbeGTMdo (ORCPT ); Fri, 20 Jul 2018 08:33:44 -0400 Received: by mail-yb0-f196.google.com with SMTP id s1-v6so4509601ybk.3; Fri, 20 Jul 2018 04:45:52 -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:user-agent; bh=6sEETIyfIWdZRxqCxHBW0J9SmgRvXDxvZJWaFQVYhbs=; b=SoTwqdmEbMmonRN971Cup0y96sOq+fVjiBQwt8k5GQW3n/CY3/uphhAc+dbm0ZQHbC WRvSknKlP5dMGiyUdna2lEg1NrNp369STOC6hvl0EjNFAdz0UCqezggg524ncXMC4R4o O8CHWpfqaQUpje/dSk3IQf7z1vU3XhVwFntucnj5TAPxJItXnBeC63IqvR+fbxqdaeGn ZgsLgpFeeWocjSdcNiPbyOJFE8RItgazlBaNJ04oTs8Ffu5BnKndtIjFDhOQsa3Zyb7K 7zjV6jLgnqoW2itWkpjHi7sDcKn7qIaEnOmBpxCmnf79JoyTNcH1aVQDLhdVT0m1MoWf 7DUw== 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:user-agent; bh=6sEETIyfIWdZRxqCxHBW0J9SmgRvXDxvZJWaFQVYhbs=; b=l2CbcaUi92IuR9bzQJofvNw9Xo6rkI2QUJ90EiRROAgHM25WEsVxr0oAtdquVd9sFA mEb8pBhziq5zywPcRikYKHwn1XG2lB3xzYnux01Ihsu/FpIJ7KHn00NWGTJdNsSIM9c1 yx54t5Gbftf0aZwnDuKy6ieiqAo5nJRDpLtqQu05UaPVrS2FsCYiCvPvg9+7KS3SmkCu W8Zkw9E2Bgjj9t1pnCdkRf1JYJm3bptY+UEasyAhCDZaRpM+SR/gS0pgiRWCoRa9BVwk pLEsjvv7EFsrf7TQEHCPlSj/4h8opJGwojBII2KuH3Fd3oGOxp27B4x+wPDfZSWS0xKT eqIA== X-Gm-Message-State: AOUpUlFloULn3EwClmCVgN81pMODfKcGUYtUqRg0SSnzYhrfnr4JH0+6 2nOIJrvE+XnyigenncvlIvs= X-Google-Smtp-Source: AAOMgpev4EXLS5twupEoWktG+YliRX/QAgf52IxrD6AxT2x1DSOZJ83Gr+NRsRmcKDzYtb40euMCGw== X-Received: by 2002:a25:63d6:: with SMTP id x205-v6mr789287ybb.248.1532087152044; Fri, 20 Jul 2018 04:45:52 -0700 (PDT) Received: from localhost ([2620:10d:c091:180::1:5c80]) by smtp.gmail.com with ESMTPSA id 141-v6sm757374ywj.65.2018.07.20.04.45.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 Jul 2018 04:45:51 -0700 (PDT) Date: Fri, 20 Jul 2018 04:45:49 -0700 From: Tejun Heo To: Peter Zijlstra Cc: Waiman Long , 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 Subject: Re: [PATCH v11 7/9] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root Message-ID: <20180720114549.GY72677@devbig577.frc2.facebook.com> References: <1529825440-9574-8-git-send-email-longman@redhat.com> <20180702165322.GI533219@devbig577.frc2.facebook.com> <20180703155823.GS533219@devbig577.frc2.facebook.com> <20180719135224.GE2494@hirez.programming.kicks-ass.net> <1107494a-9667-df58-dcac-9366e969dc3a@redhat.com> <20180719153045.GT72677@devbig577.frc2.facebook.com> <20180719165201.GU72677@devbig577.frc2.facebook.com> <20180720113121.GJ2476@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180720113121.GJ2476@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, Jul 20, 2018 at 01:31:21PM +0200, Peter Zijlstra wrote: > On Thu, Jul 19, 2018 at 09:52:01AM -0700, Tejun Heo wrote: > > On Thu, Jul 19, 2018 at 11:52:46AM -0400, Waiman Long wrote: > > > BTW, the way the partition is currently implemented right now is that a > > > child cannot be a partition root unless its parent is a partition root > > > itself. That is to avoid turning on partition to affect ancestors > > > further up the hierarchy than just the parent. So in the case of a > > > container, it cannot allocate sub-partitions underneath it unless it is > > > a partition itself. Will that solve your concern? > > > > Hmm... so a given ancestor must be able to both > > > > 1. control which cpus are moved into a partition in all of its > > subtree. > > By virtue of the partition file being owned by the parent, this is > already achived, no? The currently proposed implementation is somewhere in the middle. It kinda gets there by restricting a partition to be a child of another partition, which may be okay but it does make the whole delegation mechanism less useful. > > 2. take away any given cpu from ist subtree. > > I really hate this obsession of yours and doubly so for partitions. But > why would this currently not be allowed? Well, sorry that you hate it. It's a fundamental architectural constraint. If it can't satisfy that, it should't be in cgroup. Thanks. -- tejun