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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 605E5C7EE21 for ; Thu, 4 May 2023 17:12:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229797AbjEDRMO (ORCPT ); Thu, 4 May 2023 13:12:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229588AbjEDRMM (ORCPT ); Thu, 4 May 2023 13:12:12 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EBAC346A3 for ; Thu, 4 May 2023 10:11:38 -0700 (PDT) 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 16FCE1FB; Thu, 4 May 2023 10:12:00 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4828D3F64C; Thu, 4 May 2023 10:11:14 -0700 (PDT) Message-ID: Date: Thu, 4 May 2023 19:11:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH 1/1] sched: Consider CPU contention in frequency & load-balance busiest CPU selection Content-Language: en-US To: Vincent Guittot Cc: Ingo Molnar , Peter Zijlstra , Qais Yousef , Kajetan Puchalski , Morten Rasmussen , Vincent Donnefort , Quentin Perret , Abhijeet Dharmapurikar , linux-kernel@vger.kernel.org References: <20230406155030.1989554-1-dietmar.eggemann@arm.com> <20230406155030.1989554-2-dietmar.eggemann@arm.com> From: Dietmar Eggemann In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2023 18:08, Vincent Guittot wrote: > On Thu, 6 Apr 2023 at 17:50, Dietmar Eggemann wrote: >> >> Use new cpu_boosted_util_cfs() instead of cpu_util_cfs(). >> >> The former returns max(util_avg, runnable_avg) capped by max CPU >> capacity. CPU contention is thereby considered through runnable_avg. >> >> The change in load-balance only affects migration type `migrate_util`. > > would be good to get some figures to show the benefit Yes. Will add JankbenchX on Pixel6 for sugov_get_util() and `perf bench sched messaging` on Ampere Altra with the next version. >> Suggested-by: Vincent Guittot >> Signed-off-by: Dietmar Eggemann >> --- >> kernel/sched/cpufreq_schedutil.c | 3 ++- >> kernel/sched/fair.c | 2 +- >> kernel/sched/sched.h | 19 +++++++++++++++++++ >> 3 files changed, 22 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c >> index e3211455b203..728b186cd367 100644 >> --- a/kernel/sched/cpufreq_schedutil.c >> +++ b/kernel/sched/cpufreq_schedutil.c >> @@ -158,7 +158,8 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu) >> struct rq *rq = cpu_rq(sg_cpu->cpu); >> >> sg_cpu->bw_dl = cpu_bw_dl(rq); >> - sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), >> + sg_cpu->util = effective_cpu_util(sg_cpu->cpu, >> + cpu_boosted_util_cfs(sg_cpu->cpu), > > Shouldn't we have a similar change in feec to estimate correctly which > OPP/ freq will be selected by schedutil ? Yes, this should be more correct. Schedutil and EAS should see the world the same way. But IMHO only for the find_energy_efficient_cpu() compute_energy() eenv_pd_max_util() util = cpu_util_next(..., p, ...) effective_cpu_util(..., util, FREQUENCY_UTIL, ...) ^^^^^^^^^^^^^^ case. Not sure what I do for the task contribution? We use task_util(p)/_task_util_est(p) inside cpu_util_next(). Do I have to consider p->se.avg.runnable_avg as well? I don't think that we have a testcase showing any diff for this change individually though. [...]