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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 969A1C4361B for ; Wed, 9 Dec 2020 14:38:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 638E322B2B for ; Wed, 9 Dec 2020 14:38:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731192AbgLIOil (ORCPT ); Wed, 9 Dec 2020 09:38:41 -0500 Received: from outbound-smtp02.blacknight.com ([81.17.249.8]:36685 "EHLO outbound-smtp02.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730869AbgLIOil (ORCPT ); Wed, 9 Dec 2020 09:38:41 -0500 Received: from mail.blacknight.com (pemlinmail06.blacknight.ie [81.17.255.152]) by outbound-smtp02.blacknight.com (Postfix) with ESMTPS id DB7EABAD14 for ; Wed, 9 Dec 2020 14:37:49 +0000 (GMT) Received: (qmail 14589 invoked from network); 9 Dec 2020 14:37:49 -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); 9 Dec 2020 14:37:49 -0000 Date: Wed, 9 Dec 2020 14:37:48 +0000 From: Mel Gorman To: Peter Ziljstra , Ingo Molnar , LKML Cc: Aubrey Li , Barry Song , Juri Lelli , Vincent Guittot , Valentin Schneider , Linux-ARM Subject: Re: [PATCH 0/4] Reduce scanning of runqueues in select_idle_sibling Message-ID: <20201209143748.GP3371@techsingularity.net> References: <20201208153501.1467-1-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20201208153501.1467-1-mgorman@techsingularity.net> 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 03:34:57PM +0000, Mel Gorman wrote: > Changelog since v1 > o Drop single-pass patch (vincent) > o Scope variables used for SIS_AVG_CPU (dietmar) > o Remove redundant assignment (dietmar > > This reduces the amount of runqueue scanning in select_idle_sibling in > the worst case. > > Patch 1 removes SIS_AVG_CPU because it's unused. > > Patch 2 moves all SIS_PROP-related calculations under SIS_PROP > > Patch 3 improves the hit rate of p->recent_used_cpu to reduce the amount > of scanning. It should be relatively uncontroversial > > Patch 4 returns an idle candidate if one is found while scanning for a > free core. > Any other objections to the series? Vincent marked 1, 3 and 4 as reviewed. While patch 2 had some mild cosmetic concerns, I think the version and how it treats SIS_PROP is fine as it is to keep it functionally equivalent to !SIS_PROP and without adding too many SIS_PROP checks. -- Mel Gorman SUSE Labs