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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 4D0F8C4167B for ; Tue, 8 Dec 2020 13:37:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F3B722242 for ; Tue, 8 Dec 2020 13:37:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729441AbgLHNho (ORCPT ); Tue, 8 Dec 2020 08:37:44 -0500 Received: from outbound-smtp22.blacknight.com ([81.17.249.190]:47662 "EHLO outbound-smtp22.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729020AbgLHNho (ORCPT ); Tue, 8 Dec 2020 08:37:44 -0500 Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp22.blacknight.com (Postfix) with ESMTPS id 4F803BABD7 for ; Tue, 8 Dec 2020 13:36:52 +0000 (GMT) Received: (qmail 32152 invoked from network); 8 Dec 2020 13:36:52 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 8 Dec 2020 13:36:52 -0000 Date: Tue, 8 Dec 2020 13:36:50 +0000 From: Mel Gorman To: Vincent Guittot Cc: Dietmar Eggemann , LKML , Aubrey Li , Barry Song , Ingo Molnar , Peter Ziljstra , Juri Lelli , Valentin Schneider , Linux-ARM Subject: Re: [PATCH 1/4] sched/fair: Remove SIS_AVG_CPU Message-ID: <20201208133650.GI3371@techsingularity.net> References: <20201207091516.24683-1-mgorman@techsingularity.net> <20201207091516.24683-2-mgorman@techsingularity.net> <25a8c4bd-792b-2851-b10a-c4375eb83dfe@arm.com> <20201208105900.GG3371@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 08, 2020 at 02:24:32PM +0100, Vincent Guittot wrote: > > > Nitpick: > > > > > > Since now avg_cost and avg_idle are only used w/ SIS_PROP, they could go > > > completely into the SIS_PROP if condition. > > > > > > > Yeah, I can do that. In the initial prototype, that happened in a > > separate patch that split out SIS_PROP into a helper function and I > > never merged it back. It's a trivial change. > > while doing this, should you also put the update of > this_sd->avg_scan_cost under the SIS_PROP feature ? > It's outside the scope of the series but why not. This? --8<-- sched/fair: Move avg_scan_cost calculations under SIS_PROP As noted by Vincent Guittot, avg_scan_costs are calculated for SIS_PROP even if SIS_PROP is disabled. Move the time calculations under a SIS_PROP check and while we are at it, exclude the cost of initialising the CPU mask from the average scan cost. Signed-off-by: Mel Gorman diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 19ca0265f8aa..0fee53b1aae4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6176,10 +6176,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t nr = 4; } - time = cpu_clock(this); - cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); + if (sched_feat(SIS_PROP)) + time = cpu_clock(this); for_each_cpu_wrap(cpu, cpus, target) { if (!--nr) return -1; @@ -6187,8 +6187,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t break; } - time = cpu_clock(this) - time; - update_avg(&this_sd->avg_scan_cost, time); + if (sched_feat(SIS_PROP)) { + time = cpu_clock(this) - time; + update_avg(&this_sd->avg_scan_cost, time); + } return cpu; }