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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 83BD6C4332B for ; Mon, 23 Mar 2020 13:31:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F02120735 for ; Mon, 23 Mar 2020 13:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728489AbgCWNbE (ORCPT ); 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