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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C43FAC433F5 for ; Wed, 4 May 2022 16:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353049AbiEDQGC (ORCPT ); Wed, 4 May 2022 12:06:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244190AbiEDQGB (ORCPT ); Wed, 4 May 2022 12:06:01 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B9EC51571D for ; Wed, 4 May 2022 09:02:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651680144; 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=Kx7MkkZT+Yq+fM3GfswobHpHpBTfL9nTvycJqnYKSP8=; b=g64HKG3q7K9kl0OdgE3bVx0t56mL25HfPcdeYHdrnZG95Gt95xSWwL3EWg2VMMvjGH/6IU G/YZ2Xg/1Apbh17i2zs+e3ofB+tM9ShMxCQaqEtlrEw5zbFUbGp24Fird2Rk7fP1pdF7sz eelDZJqopjQ7GRxGKAZBsAJ5ITqW7RY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-45-MzJLmzJiNoatZxsrxTXkGw-1; Wed, 04 May 2022 12:02:23 -0400 X-MC-Unique: MzJLmzJiNoatZxsrxTXkGw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 35937805F46; Wed, 4 May 2022 16:02:22 +0000 (UTC) Received: from [10.18.17.215] (dhcp-17-215.bos.redhat.com [10.18.17.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 77B9540CF8EF; Wed, 4 May 2022 16:02:20 +0000 (UTC) Message-ID: <379138a0-1721-d6fa-4d1d-cb8d79f28474@redhat.com> Date: Wed, 4 May 2022 12:02:19 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v10 7/8] cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst Content-Language: en-US To: =?UTF-8?Q?Michal_Koutn=c3=bd?= Cc: Tejun Heo , 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 References: <20220503162149.1764245-1-longman@redhat.com> <20220503162149.1764245-8-longman@redhat.com> <20220504112552.GA15266@blackbody.suse.cz> From: Waiman Long In-Reply-To: <20220504112552.GA15266@blackbody.suse.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 5/4/22 07:25, Michal Koutný wrote: > Hello. > > On Tue, May 03, 2022 at 12:21:48PM -0400, Waiman Long wrote: >> Documentation/admin-guide/cgroup-v2.rst | 145 +++++++++++++----------- >> 1 file changed, 79 insertions(+), 66 deletions(-) > A note across various lines -- it seems your new text accidentally mixes > both spaces and tabs for indentation. You are right. I will fix that. > >> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst >> index 69d7a6983f78..94e1e3771830 100644 >> --- a/Documentation/admin-guide/cgroup-v2.rst >> +++ b/Documentation/admin-guide/cgroup-v2.rst >> [...] >> + The value shown in "cpuset.cpus.effective" of a partition root is >> + the CPUs that the parent partition root can dedicate to the new >> + partition root. They are subtracted from "cpuset.cpus.effective" >> + of the parent and may be different from "cpuset.cpus" > I find this paragraph a bit hard to comprehend (I read it as it talks > about three levels of cgroups (parent, child, grandparent). It is > correct but I'd suggect following formulation (where I additionally > simplifed it by talking about "available" cpus): > >> The value shown in "cpuset.cpus.effective" of a partition root is >> the CPUs that the partition root can dedicate to a potential new child >> partition root. The new child subtracts available CPUs from its parent >> "cpuset.cpus.effective". Thanks for the suggestion, will modify the text as suggested. > >> + For a partition root to become valid, the following conditions >> + must be met. >> + >> + 1) The "cpuset.cpus" is exclusive, i.e. they are not shared by >> + any of its siblings (exclusivity rule). >> + 2) The parent cgroup is a valid partition root. >> + 3) The "cpuset.cpus" is not empty and must contain at least >> + one of the CPUs from parent's "cpuset.cpus", i.e. they overlap. >> + 4) The "cpuset.cpus.effective" must be a subset of "cpuset.cpus" >> + and cannot be empty unless there is no task associated with >> + this partition. > This sounds good to me. > >> + Care must be taken to change a valid partition root to "member" >> + as all its child partitions, if present, will become invalid. > This does not talk about recovering. Is it intentional? (I.e. to left > implementation defined) This new patch series does have the ability to recover now.  I am just not emphasizing the recovery aspect of it in the doc file. I will add a sentence about it. > > Except the remarks above, I find the concepts described here good. I'll > reply to implementation separately & later. Thanks, Longman