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 35AD8C77B6C for ; Thu, 13 Apr 2023 00:27:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229503AbjDMA1D (ORCPT ); Wed, 12 Apr 2023 20:27:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229634AbjDMA1A (ORCPT ); Wed, 12 Apr 2023 20:27:00 -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 ESMTPS id 746AB61AB for ; Wed, 12 Apr 2023 17:26:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681345568; 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=haXTThtMgpsseSV6p+uwEaprdsyUVtg4Cg56AUYX6Mw=; b=LizBN5IIyuJuPmTHazP4E8hqso4jnNlWhUSNMcJRuDqHtFNrBiLLVanOm+w+avHTFwV+2y coB8H8EgTNqYxjUvv9unyFAhA0f8sg1ZH3YCa4e5/Z4nZ22WSfdA5C61RZ9q2LuFLkAEvE 5AzpMBYWr2jJEw7tlRTupk/eIb3Ka+Y= 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-523-xD8WZDrPMrumTqyXbLUz9g-1; Wed, 12 Apr 2023 20:26:04 -0400 X-MC-Unique: xD8WZDrPMrumTqyXbLUz9g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E8CF9185A78B; Thu, 13 Apr 2023 00:26:03 +0000 (UTC) Received: from [10.22.32.168] (unknown [10.22.32.168]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D7DE40C6E70; Thu, 13 Apr 2023 00:26:03 +0000 (UTC) Message-ID: Date: Wed, 12 Apr 2023 20:26:03 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [RFC PATCH 0/5] cgroup/cpuset: A new "isolcpus" paritition Content-Language: en-US To: Tejun Heo Cc: Zefan Li , Johannes Weiner , Jonathan Corbet , Shuah Khan , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Juri Lelli , Valentin Schneider , Frederic Weisbecker References: <20230412153758.3088111-1-longman@redhat.com> <1ce6a073-e573-0c32-c3d8-f67f3d389a28@redhat.com> From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 4/12/23 20:03, Tejun Heo wrote: > Hello, > > On Wed, Apr 12, 2023 at 04:33:29PM -0400, Waiman Long wrote: >> I think we can. You mean having a new "cpuset.cpus.isolated" cgroupfs file. >> So there will be one in the root cgroup that defines all the isolated CPUs >> one can have. It is then distributed down the hierarchy and can be claimed >> only if a cgroup becomes an "isolated" partition. There will be a slight > Yeah, that seems a lot more congruent with the typical pattern. > >> change in the semantics of an "isolated" partition, but I doubt there will >> be much users out there. > I haven't thought through it too hard but what prevents staying compatible > with the current behavior? It is possible to stay compatible with existing behavior. It is just that a break from existing behavior will make the solution more clean. So the new behavior will be:   If the "cpuset.cpus.isolated" isn't set, the existing rules applies. If it is set, the new rule will be used. Does that look reasonable to you? Cheers, Longman