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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DB5FC35640 for ; Fri, 21 Feb 2020 09:58:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D40E207FD for ; Fri, 21 Feb 2020 09:58:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbgBUJ6U (ORCPT ); Fri, 21 Feb 2020 04:58:20 -0500 Received: from foss.arm.com ([217.140.110.172]:35496 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726989AbgBUJ6T (ORCPT ); Fri, 21 Feb 2020 04:58:19 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1F951328; Fri, 21 Feb 2020 01:58:19 -0800 (PST) Received: from [192.168.0.7] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 548103F68F; Fri, 21 Feb 2020 01:58:17 -0800 (PST) Subject: Re: [PATCH v2 0/5] remove runnable_load_avg and improve group_classify To: Vincent Guittot , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org Cc: pauld@redhat.com, parth@linux.ibm.com, valentin.schneider@arm.com, hdanton@sina.com References: <20200214152729.6059-1-vincent.guittot@linaro.org> From: Dietmar Eggemann Message-ID: <827f745e-5afc-88b1-0a93-b5d2dfd796db@arm.com> Date: Fri, 21 Feb 2020 10:58:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200214152729.6059-1-vincent.guittot@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/02/2020 16:27, Vincent Guittot wrote: > This new version stays quite close to the previous one and should > replace without problems the previous one that part of Mel's patchset: > https://lkml.org/lkml/2020/2/14/156 > > NUMA load balancing is the last remaining piece of code that uses the > runnable_load_avg of PELT to balance tasks between nodes. The normal > load_balance has replaced it by a better description of the current state > of the group of cpus. The same policy can be applied to the numa > balancing. > > Once unused, runnable_load_avg can be replaced by a simpler runnable_avg > signal that tracks the waiting time of tasks on rq. Currently, the state > of a group of CPUs is defined thanks to the number of running task and the > level of utilization of rq. But the utilization can be temporarly low > after the migration of a task whereas the rq is still overloaded with > tasks. In such case where tasks were competing for the rq, the > runnable_avg will stay high after the migration. With those small things I commented on: Reviewed-by: "Dietmar Eggemann "