From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932387AbeCISU0 (ORCPT ); Fri, 9 Mar 2018 13:20:26 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50502 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751239AbeCISUY (ORCPT ); Fri, 9 Mar 2018 13:20:24 -0500 Subject: Re: [PATCH v4] cpuset: Enable cpuset controller in default hierarchy To: Mike Galbraith , 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 References: <1520609707-16582-1-git-send-email-longman@redhat.com> <1520613285.12489.36.camel@gmx.de> <1c3fe7b0-2600-c46d-1527-d3aaf024bb91@redhat.com> <1520619426.27998.18.camel@gmx.de> From: Waiman Long Organization: Red Hat Message-ID: <55809fe4-98ba-5566-86ed-457acfef0e1c@redhat.com> Date: Fri, 9 Mar 2018 13:20:22 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <1520619426.27998.18.camel@gmx.de> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/09/2018 01:17 PM, Mike Galbraith wrote: > 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 >>From your perspective, what are core functionality that should be included in cpuset v2 other than the ability to restrict cpus and memory nodes. Cheers, Longman