From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-4.5 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 560587E6B0 for ; Fri, 9 Mar 2018 18:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751434AbeCISRq convert rfc822-to-8bit (ORCPT ); Fri, 9 Mar 2018 13:17:46 -0500 Received: from mout.gmx.net ([212.227.17.20]:45515 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbeCISRp (ORCPT ); Fri, 9 Mar 2018 13:17:45 -0500 Received: from homer.simpson.net ([185.221.149.147]) by mail.gmx.com (mrgmx101 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MGEv5-1eqpfP2ky7-00FAAU; Fri, 09 Mar 2018 19:17:08 +0100 Message-ID: <1520619426.27998.18.camel@gmx.de> Subject: Re: [PATCH v4] cpuset: Enable cpuset controller in default hierarchy From: Mike Galbraith To: Waiman Long , Tejun Heo , Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, torvalds@linux-foundation.org, Roman Gushchin Date: Fri, 09 Mar 2018 19:17:06 +0100 In-Reply-To: <1c3fe7b0-2600-c46d-1527-d3aaf024bb91@redhat.com> References: <1520609707-16582-1-git-send-email-longman@redhat.com> <1520613285.12489.36.camel@gmx.de> <1c3fe7b0-2600-c46d-1527-d3aaf024bb91@redhat.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:UQrhXYr85emSsiqZS8crq9stp0HyEWuzuB4aS/22oJ6rLCckLCS UTRXcvIgpsQUSELuAFNbd4cddDjLtNAp5G8QsxnOddKL7a3vel1VxQeUjLcDBL3mo289fx5 v5t9nZAYzdYqVSr9cNhU2otYvI1tfuDIN/aXHCTZhIZyUEOYUqFuUfrstqHwmHJM9NXGtDF Pamk9JXim175274ubAdEQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:rAdCwR9PiTE=:g7V4NUbYcQlSu+5hz3v8Xp jTA7do81kojqMy9R11NCRMaz/L6XnEiHX5F6eOettoasu4Vz3dR6FWNqTCYvHL2v3DiSWsHcB dT3+RRpPlNzYWgiC3RbX5JmA7XoUTCUIn9nVcz/ImBRDiJu0+5+WQVtgHJJeR2NdlPgj3BK7c AkrHpK46nfvIB92Huxq9ifIscZZ0+3yDmHmCc+B2O1lCYjWxOCE0olY3fhheS5ZydY1oTkq7b OlC6ebUemkbzeLavTTPjXwUUE75hY0KyBE9DfLhCK41GFAh6swQb5p5L9L4NTL8WQsci/Rs7y TwdZ6KAaUnKb5ktyd53wnN31m/OYupvylBMx1P4iwDZzIfMpDE58jzF7XvyABD06rtuxwXx9N qEpisVALASxy+1FbGVlTcJ8rfCQLfVhLCwCq6Q06mwJuqNH0ZnUexhgYwQi50UWZcBqyzM/FA zdPheYaf8Wx5L+F75MGPkDlsdYKYw76RLuwCZtfHf28Y/MhcrHOgE0ft6GxNb/Pma2xCaGUEi 0X6gL2EctCgbee9KKqVU5N/CZlWxs0ZH7qeQMP9gVSsCJI0ZJ5Ry1NK2+LIJFq+464BI3e250 AIcnErT/gLQS6QiebTM3nWcfzX4XSzzhJE4daaCJifOX4uhBTzAaBo1GFmDWjs8uiXVitOA5F YM1eVPbjN8QpJEoTYHgz4RqRqyVzoFCR/NYSQva4gywmg1XYevBPOF5ijKIlwfWGvC2Pa9Hmx qC1y/g/EI+De/UhFeLuB0tkDJAxRKUrXEzeawjyPqvdZAbTVYKUBkGR3oqb+63qgXTh7HbtxN pmH1fjZMfeJq4SJ7Pe3ibzZbSWvWS4yglNX72d7eF+HlQiFaqM= Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, 2018-03-09 at 12:45 -0500, Waiman Long wrote: > On 03/09/2018 11:34 AM, Mike Galbraith wrote: > > On Fri, 2018-03-09 at 10:35 -0500, Waiman Long wrote: > >> Given the fact that thread mode had been merged into 4.14, it is now > >> time to enable cpuset to be used in the default hierarchy (cgroup v2) > >> as it is clearly threaded. > >> > >> The cpuset controller had experienced feature creep since its > >> introduction more than a decade ago. Besides the core cpus and mems > >> control files to limit cpus and memory nodes, there are a bunch of > >> additional features that can be controlled from the userspace. Some of > >> the features are of doubtful usefulness and may not be actively used. > > One rather important features is the ability to dynamically partition a > > box and isolate critical loads. How does one do that with v2? > > > > In v1, you create two or more exclusive sets, one for generic > > housekeeping, and one or more for critical load(s), RT in my case, > > turning off load balancing in the critical set(s) for obvious reasons. > > This patch just serves as a foundation for cpuset support in v2. I am > not excluding the fact that more v1 features will be added in future > patches. We want to start with a clean slate and add on it after careful > consideration. There are some v1 cpuset features that are not used or > rarely used. We certainly want to get rid of them, if possible. If v2 is to ever supersede v1, as is the normal way of things, core functionality really should be on the v2 boat when it sails.  What you left standing on the dock is critical core cpuset functionality. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html