Received: by 2002:a05:6a10:f347:0:0:0:0 with SMTP id d7csp4057639pxu; Wed, 9 Dec 2020 07:22:52 -0800 (PST) X-Google-Smtp-Source: ABdhPJzqxeRR+5Gwt9wu27RFN5vLLmHJR7R+8WJ0sWI7jTX0kPbaZkAVHRn4gU8Bxy7EZzEouGJW X-Received: by 2002:a17:906:60d2:: with SMTP id f18mr2416730ejk.528.1607527372229; Wed, 09 Dec 2020 07:22:52 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1607527372; cv=none; d=google.com; s=arc-20160816; b=uoemlmMsgL/vZ+SqeMRZqK500yGms9YVwaPz5gJRylF2dZU5DD316Fr1+iHCGqwyGM nt1lhjpz/haMcENb3CZZQ7e/PQST8EdCzuty1y/es1RCAM3+9AhYfraFoxxruvW/YyVh GGHgaZRsLROHb+QmbBEzEAlo/gXH5DT7CdY9oG3oPGocMYVMnLnwxhjrs14YOZIKI715 r00fxq0Xb6zBwfHPqyfgJCsN32e0nQj6dLcHNgS2o3nGGEw6cyanU+XsbdlcPtVwDCZI wgfWEwwmAhsJyKxjB2GKZ8L/FDO4dXuMDsJ4D8FB40GXypaOR/tOsUVkA2rwbb/JjcEP XFww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=wdXDf1MbDiAcxURGG5WzfGCkDcaY37q2fvBEiXdORcw=; b=sRtwkEgGtx/g/c44sbQacuXeiVz5h91rak2t6ySOhce9TDHgufwlMXbu27UpJQQ9mZ B22ZuIQSzwG+HB8sg5NKjTnqRrhU5D8Q4nihif+unLcc9MrBNmLhD4J9vOA7QEHRTemJ 93t6QEDv0W43FuTac53ObsCzdsvJSDIBQ6XyhDJkEJyk+TFzjaNXEUEStmH1A9bRCScg s7ZsDjFxLi4KVKHT8oOTvE6NnQFM+D7wrLs2VsyhA6GUecnU0qb1tLyBZrxJBJGiQkVz va5KzgGzVq8OH3jdr42CXM9mGqLIieT8h370PohArW4WqrLh6QRoEOcSUJ2+RCTy33t8 hxTA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id y9si1040266edq.205.2020.12.09.07.22.29; Wed, 09 Dec 2020 07:22:52 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731133AbgLIOil (ORCPT + 99 others); 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