Received: by 2002:a05:6a10:f347:0:0:0:0 with SMTP id d7csp3264104pxu; Tue, 8 Dec 2020 07:39:27 -0800 (PST) X-Google-Smtp-Source: ABdhPJyB3OtEpqRQAUY/oDpQ+Q7dEd39Glf0XGdHh7rdpq7NNr1V+pWxMwsro7doVtG4uGon6ulE X-Received: by 2002:a50:fb97:: with SMTP id e23mr25679099edq.208.1607441967139; Tue, 08 Dec 2020 07:39:27 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1607441967; cv=none; d=google.com; s=arc-20160816; b=kH1k5IAOqZglshPGMtS9Dx5wvgt2Chl00qrmYKgt/oTUXNuIt7fd9darPZkTl+TVkt bqV9b7f1U5Kw9DrKLxmpeg6GrbyzHBh1UxM8dzfWKCB5MvAnIOJc9e16npP13D4CpT+J DtCt7Fmlzr2UcrweksIkyA3Sf1QXvgZcpeidyM1kqkd0k64IelOTH10Ru6lTgt9EBgVk o+9iIVMs+qAYwTmrH+ZII2mYl7gMJPjT2utoDFaE08K0mGcysP4IUp6MQdMqq16WAlDd ra3JtNPKX95a4FdtCcNEQLdqKppS9VSKxFO3Aoze5Eh33lFZKKk/1K6Q0rnfoRyhOOgX yRBQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=nVnzEjyufBs3mDBrAs/PABK6+Ls14ooJHxtj/ByjPf0=; b=Oa8d3AoUtMHfHVBnDeX1eGIbqygUCP9zk0oyNsxZyF9lR792PhHkD6TajE46UzFP6L yuoTCRZFxVNoGHWjEppaBWlHDozUez1/HTCaQzlmNUFc1/NMNf8J/Ebcmr3FTQU+fHZI fOXvGk4iidAxF/SG/1Xg4r1P4oUQ9gdF/nzYXVUVEboxt3UJjTe1FyWbANA/lp8mY8qR wWL95KqJazzAfOTInLHDvcAlQViotp9YQnVBRzlazLvI7s4YGs1yYhI1YO9MpR6JnMBg GHD3F5B580kRnkV95N+oSW9T6BXWTCIT11Y2QocsTty/s9acS0BA2TaCqtnrIStWyq+f UPVQ== 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 e16si8509648eja.462.2020.12.08.07.39.02; Tue, 08 Dec 2020 07:39:27 -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 S1730049AbgLHPgF (ORCPT + 99 others); Tue, 8 Dec 2020 10:36:05 -0500 Received: from outbound-smtp19.blacknight.com ([46.22.139.246]:45239 "EHLO outbound-smtp19.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730001AbgLHPgE (ORCPT ); Tue, 8 Dec 2020 10:36:04 -0500 Received: from mail.blacknight.com (pemlinmail04.blacknight.ie [81.17.254.17]) by outbound-smtp19.blacknight.com (Postfix) with ESMTPS id 196721C3B7A for ; Tue, 8 Dec 2020 15:35:13 +0000 (GMT) Received: (qmail 9668 invoked from network); 8 Dec 2020 15:35:12 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 8 Dec 2020 15:35:12 -0000 From: Mel Gorman To: Peter Ziljstra , Ingo Molnar , LKML Cc: Aubrey Li , Barry Song , Juri Lelli , Vincent Guittot , Valentin Schneider , Linux-ARM , Mel Gorman Subject: [PATCH 0/4] Reduce scanning of runqueues in select_idle_sibling Date: Tue, 8 Dec 2020 15:34:57 +0000 Message-Id: <20201208153501.1467-1-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- 2.26.2 Mel Gorman (4): sched/fair: Remove SIS_AVG_CPU sched/fair: Move avg_scan_cost calculations under SIS_PROP sched/fair: Do not replace recent_used_cpu with the new target sched/fair: Return an idle cpu if one is found after a failed search for an idle core kernel/sched/fair.c | 51 ++++++++++++++++++++--------------------- kernel/sched/features.h | 1 - 2 files changed, 25 insertions(+), 27 deletions(-) -- 2.26.2