From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451AbeEBOfs (ORCPT ); Wed, 2 May 2018 10:35:48 -0400 Received: from mout.gmx.net ([212.227.15.15]:56939 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbeEBOfo (ORCPT ); Wed, 2 May 2018 10:35:44 -0400 Message-ID: <1525271702.4975.3.camel@gmx.de> Subject: Re: [PATCH v7 2/5] cpuset: Add cpuset.sched_load_balance to v2 From: Mike Galbraith To: Peter Zijlstra , Waiman Long Cc: Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , 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 , Juri Lelli Date: Wed, 02 May 2018 16:35:02 +0200 In-Reply-To: <20180502140226.GU12217@hirez.programming.kicks-ass.net> References: <1524145624-23655-1-git-send-email-longman@redhat.com> <1524145624-23655-3-git-send-email-longman@redhat.com> <20180502102416.GJ12180@hirez.programming.kicks-ass.net> <14d7604c-1254-1146-e2b6-23f4cc020b34@redhat.com> <20180502134225.GR12217@hirez.programming.kicks-ass.net> <94c80e1c-049d-6ec3-8e8c-40eb88d1341d@redhat.com> <20180502140226.GU12217@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:zEAieqQMBsuU9mkUlzU7cM4ZhLBj9AKeFJ4tDfwPOf+yuOehqN2 jM47W3pvYdw1vatfNrsSLBj7tgIknHDA/H3iC389u/qTl9qpsmJJaPFAb9t1VeyWyvNnXbK BEBkhppNzW1SCQ7CdpOiTWQAhGtoXXu4ybM8IWXGrgNxvtMBTVaYJYqzVcOymqBMtg4M2DU W17PKy50U+hTkj1LDTwWQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:/HeTV7Ohtmc=:D2DYh1zeJwuqDrCuQN0G/U 3sATyrc/rriSpfI0QVU1cHKdd4xztKjclC4ltAl2InMbs8tgAy+cpYaoxej6xBqfrcFSBIQou NVRRYvU6mp8jahASSfQ8EwdAgbEvH+AZ2T3ctM2aFUJxflTnbuvX8au3YlZaC/eiJYHJpa1SW Ps7qy3D7FB3vSuSIvq+2p5lHqJWDCVjBiHsPXAlcEn9/KJoDmHGDzfchfGdK7Zc6sp5eck9fr BSNySXIgJhwmazOTGh3n8UTi/EtDdKArXsYL8gJz2P8GpcU/ys675QtAZY6Tk+QtSjULrXXAX IT9E8ZhybvAXuuaksbUqPFAeyuRTQ9t1LvqqdN7jSNroBv2KzLLqQuFqUok4l1ykU4IpdRiup Vwc0L71FDlnFAOXOThHUjKTfZAx9uPPGTxMbesGqCn13m0Er6J5cTJ25cVZXKxlEwfe/LSu9+ 8fUQrxytoZC6dcS6mWvFxWx4gEnsVDg2rvUJrlURu2hK2ZlgpW4Cbzzu9U3o751DLheHX6ycS z4hGTukN9+PWi5QafbuBWspfKhqtF2uhZosrFimPBaMs4IsiuFmwjcaQ0P4Rf133KYfTxVpWy ihfoJL3iO0FyQeUtJZXCXfL9NCcgEyztgT8ddlLn7RlKpkSMAJrM+yAOirIAcH/+PkO/5TMBC 6CdLUaHsHZLPwadDNfSUW2jF8ox30pjLzaRjn9fa2q3u7Vhf32xSb4t4vxg5/LMeGSj1X5IAb /hNozgMzYxUouI3/H6gy1QT96Tv7WFOfMYAWwTtqvubxelEdrQxqjPk6sejB7miWq+Z3aJDoo kKZpbx/ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-05-02 at 16:02 +0200, Peter Zijlstra wrote: > On Wed, May 02, 2018 at 09:47:00AM -0400, Waiman Long wrote: > > > > I've read half of the next patch that adds the isolation thing. And > > > while that kludges around the whole root cgorup is magic thing, it > > > doesn't help if you move the above scenario on level down: > > > > > > > > > R > > > / \ > > > A B > > > / \ > > > C D > > > > > > > > > R: cpus=0-7, load_balance=0 > > > A: cpus=0-1, load_balance=1 > > > B: cpus=2-7, load_balance=0 > > > C: cpus=2-3, load_balance=1 > > > D: cpus=4-7, load_balance=1 > > > > > > > > > Also, I feel we should strive to have a minimal amount of tasks that > > > cannot be moved out of the root group; the current set is far too large. > > > > What exactly is the use case you have in mind with loading balancing > > disabled in B, but enabled in C and D? We would like to support some > > sensible use cases, but not every possible combinations. > > Suppose A is your system group, and C and D are individual RT workloads > or something. Yeah, it does have a distinct "640K ought to be enough for anybody" flavor to it. -Mike