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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 5D507C433E0 for ; Sun, 24 Jan 2021 20:39:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ADD822C7B for ; Sun, 24 Jan 2021 20:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726545AbhAXUi7 (ORCPT ); Sun, 24 Jan 2021 15:38:59 -0500 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:16596 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726424AbhAXUi4 (ORCPT ); Sun, 24 Jan 2021 15:38:56 -0500 X-IronPort-AV: E=Sophos;i="5.79,372,1602540000"; d="scan'208";a="488781309" Received: from 173.121.68.85.rev.sfr.net (HELO hadrien) ([85.68.121.173]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jan 2021 21:38:14 +0100 Date: Sun, 24 Jan 2021 21:38:14 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Mel Gorman cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Daniel Bristot de Oliveira , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] sched/fair: check for idle core In-Reply-To: <20201027091936.GS32041@suse.de> Message-ID: References: <1603372550-14680-1-git-send-email-Julia.Lawall@inria.fr> <20201027091936.GS32041@suse.de> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Oct 2020, Mel Gorman wrote: > On Thu, Oct 22, 2020 at 03:15:50PM +0200, Julia Lawall wrote: > > Fixes: 11f10e5420f6 ("sched/fair: Use load instead of runnable load in wakeup path") > > Signed-off-by: Julia Lawall > > Reviewed-by Vincent Guittot > > > > While not a universal win, it was mostly a win or neutral. In few cases > where there was a problem, one benchmark I'm a bit suspicious of generally > as occasionally it generates bad results for unknown and unpredictable > reasons. In another, it was very machine specific and the differences > were small in absolte time rather than relative time. Other tests on the > same machine were fine so overall; > > Acked-by: Mel Gorman Recently, we have been testing the phoronix multicore benchmarks. On v5.9 with this patch, the preparation time of phoronix slows down, from ~23 seconds to ~28 seconds. In v5.11-rc4, we see 29 seconds. It's not yet clear what causes the problem. But perhaps the patch should be removed from v5.11, until the problem is understood. commit d8fcb81f1acf651a0e50eacecca43d0524984f87 julia > > Thanks. > > -- > Mel Gorman > SUSE Labs >