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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 64965C352A3 for ; Sat, 15 Feb 2020 21:58:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4017E2084E for ; Sat, 15 Feb 2020 21:58:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727868AbgBOV6d (ORCPT ); Sat, 15 Feb 2020 16:58:33 -0500 Received: from mx2.suse.de ([195.135.220.15]:35378 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726254AbgBOV6d (ORCPT ); Sat, 15 Feb 2020 16:58:33 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EA4CFADD7; Sat, 15 Feb 2020 21:58:28 +0000 (UTC) Date: Sat, 15 Feb 2020 21:58:24 +0000 From: Mel Gorman To: Vincent Guittot Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, linux-kernel@vger.kernel.org, pauld@redhat.com, parth@linux.ibm.com, valentin.schneider@arm.com, hdanton@sina.com Subject: Re: [PATCH v2 0/5] remove runnable_load_avg and improve group_classify Message-ID: <20200215215823.GY3420@suse.de> References: <20200214152729.6059-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20200214152729.6059-1-vincent.guittot@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 14, 2020 at 04:27:24PM +0100, Vincent Guittot wrote: > This new version stays quite close to the previous one and should > replace without problems the previous one that part of Mel's patchset: > https://lkml.org/lkml/2020/2/14/156 > As far as I can see, the differences are harmless and look sane. I do think that an additional fix is mandatory as I see no reason why the regression was fixed. As such, I'll release a v3 of the series that includes your new patches with the minimal fix inserted where appropriate. I'll have tests running over the rest of the weekend. > Some hackbench results: > > - small arm64 dual quad cores system > hackbench -l (2560/#grp) -g #grp > > grp tip/sched/core +patchset improvement > 1 1,327(+/-10,06 %) 1,247(+/-5,45 %) 5,97 % > 4 1,250(+/- 2,55 %) 1,207(+/-2,12 %) 3,42 % > 8 1,189(+/- 1,47 %) 1,179(+/-1,93 %) 0,90 % > 16 1,221(+/- 3,25 %) 1,219(+/-2,44 %) 0,16 % > > - large arm64 2 nodes / 224 cores system > hackbench -l (256000/#grp) -g #grp > > grp tip/sched/core +patchset improvement > 1 14,197(+/- 2,73 %) 13,917(+/- 2,19 %) 1,98 % > 4 6,817(+/- 1,27 %) 6,523(+/-11,96 %) 4,31 % > 16 2,930(+/- 1,07 %) 2,911(+/- 1,08 %) 0,66 % > 32 2,735(+/- 1,71 %) 2,725(+/- 1,53 %) 0,37 % > 64 2,702(+/- 0,32 %) 2,717(+/- 1,07 %) -0,53 % > 128 3,533(+/-14,66 %) 3,123(+/-12,47 %) 11,59 % > 256 3,918(+/-19,93 %) 3,390(+/- 5,93 %) 13,47 % > > The significant improvement for 128 and 256 should be taken with care > because of some instabilities over iterations without the patchset. > For the most part I do not see similar results to this with hackbench with one exception -- EPYC first generation. I don't have results for EPYC 2 yet but I'm curious if the machine you have has multiple L3 caches per NUMA domain? Various Intel CPU generations show improvements but they're not as dramatic. Tests will tell me for sure but I have some confidence that it'll look like Small tracing patches -- no difference Vincent Patches 1-2 -- regressions Fix from Mel -- small overall improvement on baseline Vincent patches 3-5 -- small improvements mostly, sometimes big ones on hackbench depending on the machine Rest of Mel series -- generally ok across machines and CPU generations Even if the improvements are not dramatic, I think it'll be worth it to have NUMA and CPU balancer using similarly sane logic and overall I find the load balancer easier to understand with the new logic so yey! -- Mel Gorman SUSE Labs