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=-8.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 F31DEC432BE for ; Tue, 10 Aug 2021 01:12:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D70D461052 for ; Tue, 10 Aug 2021 01:12:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237183AbhHJBMo (ORCPT ); Mon, 9 Aug 2021 21:12:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47214 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229739AbhHJBMn (ORCPT ); Mon, 9 Aug 2021 21:12:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628557941; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=b7XJ3sqkjfHFuPFTck2dP2wBhFySTzytxDlqqd+iwHA=; b=h1OFKbIIeaeupfqAQWeURjAt5qoHseogEQGFEhh3RL8PrXaUpF13xi1G48mDcsW5MF+s9S weJqAxJvvoTMDTJc2MBycqwaj8kX1U70jFR+KS4uVLJjDHo8SoQBzlG22updBhcbR/SMvK XRS0KBIrlRYwIKkdJuRjzwXBa9DXq0k= Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-254-I4v62UH9NGK-WvHWexbIsw-1; Mon, 09 Aug 2021 21:12:20 -0400 X-MC-Unique: I4v62UH9NGK-WvHWexbIsw-1 Received: by mail-qk1-f200.google.com with SMTP id h5-20020a05620a0525b02903b861bec838so14212447qkh.7 for ; Mon, 09 Aug 2021 18:12:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=b7XJ3sqkjfHFuPFTck2dP2wBhFySTzytxDlqqd+iwHA=; b=i8M8Go4b+WDogJhW9arkSQvOAgZ9hgoUts5sXVAT2nzLbSJ0Rnm8QzHTW6j6TPY0a8 35PLJRlwgKucP7qHujMphW59OmjEJh7EfgAtBLNUYqfjHw2NBJBaYi+UsI6ZelaHIlwF h79j0z6oq6eicptkCIsrB239esQSlKrrqD0qiVcgolmcq0xLYQxTwA0dMUEqlp/L1ODy SEhc4UtWuSAQsR/W5rl/u5RS/in5C55ld1f+H4aiGNIusrNqHAhzwShlSR/fgeoNrvct 1Xs0xBWZjqSBnezCgCqG36q3VuQF6o/6PCzP30csd6BXBEOZaWO/dG/4jWp+L6JcgMrT rngQ== X-Gm-Message-State: AOAM533xHaRJd7ZvSCzntk9OgGmbVvV9TC2RwEaNvGPJsLsPc70o1kY2 sPY++ycwY3Y3j03BdNNz4HmI91OdKHWquVpoISG+ouMB9q7sFQR8rqBLBwvC0ZKbFFVOruGBxB/ HGDJFKf8lVrdCzzaC9NnO X-Received: by 2002:ac8:5385:: with SMTP id x5mr7914714qtp.369.1628557940373; Mon, 09 Aug 2021 18:12:20 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxF6rIf3rD64IJtihYoHCyLMTR4SvYsVu31YT92d5TjMiatftJQfAismFO2/uJ2ApU7xiMVEQ== X-Received: by 2002:ac8:5385:: with SMTP id x5mr7914688qtp.369.1628557940198; Mon, 09 Aug 2021 18:12:20 -0700 (PDT) Received: from llong.remote.csb ([2601:191:8500:76c0::cdbc]) by smtp.gmail.com with ESMTPSA id b22sm2183568qtr.2.2021.08.09.18.12.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Aug 2021 18:12:19 -0700 (PDT) From: Waiman Long X-Google-Original-From: Waiman Long Subject: Re: [PATCH v3 0/9] cgroup/cpuset: Add new cpuset partition type & empty effecitve cpus To: Tejun Heo , Waiman Long Cc: Zefan Li , Johannes Weiner , Jonathan Corbet , Shuah Khan , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrew Morton , Roman Gushchin , Phil Auld , Peter Zijlstra , Juri Lelli , Frederic Weisbecker , Marcelo Tosatti , =?UTF-8?Q?Michal_Koutn=c3=bd?= References: <20210720141834.10624-1-longman@redhat.com> Message-ID: <1df2d0be-f2b7-3e57-e656-2bcdf2a3c821@redhat.com> Date: Mon, 9 Aug 2021 21:12:18 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 8/9/21 6:46 PM, Tejun Heo wrote: > Hello, Waiman. Sorry about the delay. Was off for a while. > > On Tue, Jul 27, 2021 at 05:14:27PM -0400, Waiman Long wrote: >> However, if we have a complicated partition setup with multiple child >> partitions. Invalid cpuset.cpus change in a parent partition will cause all >> the child partitions to become invalid too. That is the scenario that I >> don't want to happen inadvertently. Alternatively, we can restrict those > I don't think there's anything fundamentally wrong with it given the > requirement that userland has to monitor invalid state transitions. > The same mass transition can happen through cpu hotplug operations, > right? > >> invalid changes if a child partition exist and let it pass through and make >> it invalid if it is a standalone partition. >> >> Please let me know which approach do you want me to take. > I think it'd be best if we can stick to some principles rather than > trying to adjust it for specific scenarios. e.g.: > > * If a given state can be reached through cpu hot [un]plug, any > configuration attempt which reaches the same state should be allowed > with the same end result as cpu hot [un]plug. > > * If a given state can't ever be reached in whichever way, the > configuration attempting to reach such state should be rejected. OK, I got it. I will make the necessary changes and submit a new patch series. Thanks, Longman