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 64BD3C4338F for ; Tue, 10 Aug 2021 01:12:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43A056101E for ; Tue, 10 Aug 2021 01:12:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237192AbhHJBMq (ORCPT ); Mon, 9 Aug 2021 21:12:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:20193 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229739AbhHJBMp (ORCPT ); Mon, 9 Aug 2021 21:12:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628557944; 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=gnsd7INDd5MncLtWelTlO1/P8K74gr0iQHRSPvuJBBKq3lv2Y2bne8Pe9JcYiG26mjioYW zZEbOHV6cf6rfGE0kGK+9Gn6IEsrN26xhbl2XFghVYAaA3kkAxgyK11bJ+uSSFwQx3ZWdw fL9MBeS60G0nA2ijDJXk6qeviOyz11I= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-236-nQs-BO7IMVmodbzTXTI7HQ-1; Mon, 09 Aug 2021 21:12:20 -0400 X-MC-Unique: nQs-BO7IMVmodbzTXTI7HQ-1 Received: by mail-qt1-f198.google.com with SMTP id w11-20020ac857cb0000b029024e7e455d67so9158149qta.16 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=JPgaUYyY0uSl4MyndA12RzjZNHe30R0A8lH2J4N7gNknr881xv5SbbOMTL+tCbpmFh ogMjhwE285WaX7nRAUzmOTypho8bYyp5hyiIdSGo+jAEnNhFSpbsQ2dhPzwGIlthrhtA Zx4m8fzQwWB6u1K8JzfBbsBi77rG4jvHyGHUrArDPlOhCtWzo8IWjAyB3YBesy2C0n54 b+jm0VEcCJTGHd4R7cBSMCpZhIDerviB91oIQnmZ3oIZORmTzkgVyS/PKJfKlVnDG7aj 3Wz32BmIU+NBApQYva0xDA/vkwYvzQkUuugd0czc8BSHY2AAAhpi5Bl5549I9JbrpJ4N zDjg== X-Gm-Message-State: AOAM532X7l9dH1WxCJ+mGNeTnPVFr4LQK5T3Ca5X/FaEbw0WxcI1mKyk PSi11S7Lfteo5uux2MhU61rFbqu4hhJTbSjnw1CVqaDsee3rLQYfHUn9dl4glU1DDHOxkTFtrvW a0ZHNFMmi0c0CiBUmz4Rhy8bq X-Received: by 2002:ac8:5385:: with SMTP id x5mr7914702qtp.369.1628557940372; 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-kernel@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