Received: by 2002:a25:6193:0:0:0:0:0 with SMTP id v141csp3721748ybb; Mon, 23 Mar 2020 06:32:08 -0700 (PDT) X-Google-Smtp-Source: ADFU+vscW1+iVWBHZCnevuCItf4YLCG1CSfb06QxHOXxKRogt2nQYbwpm0cOQyGM+EvSybqMSY92 X-Received: by 2002:a9d:4c98:: with SMTP id m24mr18733975otf.158.1584970328144; Mon, 23 Mar 2020 06:32:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1584970328; cv=none; d=google.com; s=arc-20160816; b=g0Zk131SnCaWzvY7YSnOuOIt02bwssDvibmIwqzIRsvN5As9DqHwaXEWiJjmeW7tk3 6Lwz0laKepALg/yPsZv9RmYd4r03gLQXAca0GfqGYUh81BPwJwEpdoFSnqfhh3JkWWXn 6W+rsr+/2iSHAKLqtOJrbv9Lqubw39bIZQMusnTSwOwGVcqSA0MZ8Q7FNJyvRk/67xL8 IVI2YS1sikt3apDXj5zdTHQf73R8DrWXjX7gVRFGxkJ7tyAwCfuV6oCvtWDj+4q1XVU7 J3lU0FYlmf69oSaaB3MjABPV1E024dudJa2kXAdD+iKcZ4dCIkctGswOUhY8dc5vlkbu aHbQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:message-id:date:in-reply-to :subject:cc:to:from:user-agent:references; bh=osvCifluJDxAmrPCWzVVvzQQlbnfs6D0B/+5Ik2ozxQ=; b=TvOle6FwcYClO1f6BOGhdacefPcaF0QUuQLyd5AI230c4snwCH7ucf31iS6pASmIxc w7znyQjYGVd3Q0h77AuaJfjyViL396w2Tf6V/tahfxsaQr2hubyPxgOIGsp4+IKTNWrH fSG++srsLf7/y0wyksK1+NN9aWWcBygdlOT1ieeUKuTSGECGOO5H0LnNNgXhzogUhp7I Yov/pjaC9M/f5w8nVs+RlJN+50SyFWXTByrjoHZwo0zXodcVwh96X0hxflglWQ+IhH6p iP4lk/Ptt+aJ+QzVx0ucFeMbEXfGkooMAgdXAqT9ypvlfqdmG7k700BWc8G3o3Mpq+i7 tTmA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r29si8133737oth.324.2020.03.23.06.31.55; Mon, 23 Mar 2020 06:32:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728465AbgCWNbE (ORCPT + 99 others); Mon, 23 Mar 2020 09:31:04 -0400 Received: from foss.arm.com ([217.140.110.172]:49076 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728355AbgCWNbE (ORCPT ); Mon, 23 Mar 2020 09:31:04 -0400 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 71F9A1FB; Mon, 23 Mar 2020 06:31:03 -0700 (PDT) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8D0113F52E; Mon, 23 Mar 2020 06:31:02 -0700 (PDT) References: <20200320151245.21152-1-mgorman@techsingularity.net> <20200320151245.21152-4-mgorman@techsingularity.net> User-agent: mu4e 0.9.17; emacs 26.3 From: Valentin Schneider To: Mel Gorman Cc: Ingo Molnar , Peter Zijlstra , Vincent Guittot , Phil Auld , LKML Subject: Re: [PATCH 3/4] sched/fair: Clear SMT siblings after determining the core is not idle In-reply-to: <20200320151245.21152-4-mgorman@techsingularity.net> Date: Mon, 23 Mar 2020 13:31:00 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 20 2020, Mel Gorman wrote: > The clearing of SMT siblings from the SIS mask before checking for an idle > core is a small but unnecessary cost. Defer the clearing of the siblings > until the scan moves to the next potential target. The cost of this was > not measured as it is borderline noise but it should be self-evident. > > Signed-off-by: Mel Gorman Reviewed-by: Valentin Schneider