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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 B810BC433DF for ; Tue, 25 Aug 2020 13:58:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E2E62075F for ; Tue, 25 Aug 2020 13:58:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726180AbgHYN6q (ORCPT ); Tue, 25 Aug 2020 09:58:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:44416 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725893AbgHYN6o (ORCPT ); Tue, 25 Aug 2020 09:58:44 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 69977AFAE; Tue, 25 Aug 2020 13:59:14 +0000 (UTC) Date: Tue, 25 Aug 2020 14:58:41 +0100 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 Subject: Re: [PATCH] sched/numa: use runnable_avg to classify node Message-ID: <20200825135841.GC3033@suse.de> References: <20200825121818.30260-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20200825121818.30260-1-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 Tue, Aug 25, 2020 at 02:18:18PM +0200, Vincent Guittot wrote: > Use runnable_avg to classify numa node state similarly to what is done for > normal load balancer. This helps to ensure that numa and normal balancers > use the same view of the state of the system. > > - large arm64system: 2 nodes / 224 CPUs > hackbench -l (256000/#grp) -g #grp > > grp tip/sched/core +patchset improvement > 1 14,008(+/- 4,99 %) 13,800(+/- 3.88 %) 1,48 % > 4 4,340(+/- 5.35 %) 4.283(+/- 4.85 %) 1,33 % > 16 3,357(+/- 0.55 %) 3.359(+/- 0.54 %) -0,06 % > 32 3,050(+/- 0.94 %) 3.039(+/- 1,06 %) 0,38 % > 64 2.968(+/- 1,85 %) 3.006(+/- 2.92 %) -1.27 % > 128 3,290(+/-12.61 %) 3,108(+/- 5.97 %) 5.51 % > 256 3.235(+/- 3.95 %) 3,188(+/- 2.83 %) 1.45 % > Intuitively the patch makes sense but I'm not a fan of using hackbench for evaluating NUMA balancing. The tasks are too short-lived and it's not sensitive enough to data placement because of the small footprint and because hackbench tends to saturate a machine. As predicting NUMA balancing behaviour in your head can be difficult, I've queued up a battery of tests on a few different NUMA machines and will see what falls out. It'll take a few days as some of the tests are long-lived. Baseline will be 5.9-rc2 as I haven't looked at the topology rework in tip/sched/core and this patch should not be related to it. -- Mel Gorman SUSE Labs