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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 22C4DC433ED for ; Fri, 30 Apr 2021 11:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEB4361418 for ; Fri, 30 Apr 2021 11:04:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229911AbhD3LFC (ORCPT ); Fri, 30 Apr 2021 07:05:02 -0400 Received: from foss.arm.com ([217.140.110.172]:45636 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbhD3LFB (ORCPT ); Fri, 30 Apr 2021 07:05:01 -0400 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 AE8A5ED1; Fri, 30 Apr 2021 04:04:01 -0700 (PDT) Received: from [10.57.29.245] (unknown [10.57.29.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7D2F73F70D; Fri, 30 Apr 2021 04:03:58 -0700 (PDT) Subject: Re: [PATCH v2 1/2] sched/fair: Only compute base_energy_pd if necessary To: Pierre.Gondois@arm.com Cc: linux-kernel@vger.kernel.org, xuewen.yan@unisoc.com, qperret@qperret.net, dietmar.eggemann@arm.com, Vincent.Donnefort@arm.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com References: <20210429101948.31224-1-Pierre.Gondois@arm.com> <20210429101948.31224-2-Pierre.Gondois@arm.com> From: Lukasz Luba Message-ID: Date: Fri, 30 Apr 2021 12:03:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20210429101948.31224-2-Pierre.Gondois@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pierre, On 4/29/21 11:19 AM, Pierre.Gondois@arm.com wrote: > From: Pierre Gondois > > find_energy_efficient_cpu() searches the best energy CPU > to place a task on. To do so, the energy of each performance domain > (pd) is computed w/ and w/o the task placed in each pd. > > The energy of a pd w/o the task (base_energy_pd) is computed prior > knowing whether a CPU is available in the pd. > > Move the base_energy_pd computation after looping through the CPUs > of a pd and only computes it if at least one CPU is available. > > Suggested-by: Xuewen Yan > Signed-off-by: Pierre Gondois > --- > kernel/sched/fair.c | 38 ++++++++++++++++++++++---------------- > 1 file changed, 22 insertions(+), 16 deletions(-) > Make sense. I will speed-up feec() on Android devices for tasks being moved into 'background' cgroup (limited to subset of CPUs, e.g. to only Little cores). LGTM. Reviewed-by: Lukasz Luba Regards, Lukasz