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=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 39993C48BE8 for ; Fri, 18 Jun 2021 19:22:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1559D61261 for ; Fri, 18 Jun 2021 19:22:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231936AbhFRTZF (ORCPT ); Fri, 18 Jun 2021 15:25:05 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:31929 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230433AbhFRTZE (ORCPT ); Fri, 18 Jun 2021 15:25:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624044174; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3ZW59nW/WyoTacwt3Dz2q15uu3UXU++wAjCRWyOYFw=; b=CpsDepTmbUtkZgQuRpkLlvjtiJxzSvj1BgAu5SGYQs4kRsXXMClb1JKME00kHZOwAtxtzF aQl8q+eLdttQu39ya2/lQQotmSdJhBWqh3TSyhmH8pHBxUy10NsGaYc8ZNUIyVLcdE4S54 kBe12tSiRTJXrqBPIuQR5qPt0kbw9Vw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-238-BrrcNyV5PeiR_UGZMXRblQ-1; Fri, 18 Jun 2021 15:22:52 -0400 X-MC-Unique: BrrcNyV5PeiR_UGZMXRblQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 848F0800C78; Fri, 18 Jun 2021 19:22:51 +0000 (UTC) Received: from lorien.usersys.redhat.com (unknown [10.22.8.140]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 39DAF17B4C; Fri, 18 Jun 2021 19:22:43 +0000 (UTC) Date: Fri, 18 Jun 2021 15:22:41 -0400 From: Phil Auld To: Mel Gorman Cc: Peter Zijlstra , Ingo Molnar , Juri Lelli , Vincent Guittot , Valentin Schneider , LKML Subject: Re: [PATCH v2] sched/fair: Age the average idle time Message-ID: References: <20210615111611.GH30378@techsingularity.net> <20210615204228.GB4272@worktop.programming.kicks-ass.net> <20210616090314.GJ30378@techsingularity.net> <20210617154006.GQ30378@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210617154006.GQ30378@techsingularity.net> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 17, 2021 at 04:40:06PM +0100 Mel Gorman wrote: > On Thu, Jun 17, 2021 at 11:01:16AM -0400, Phil Auld wrote: > > > Thanks, so far no serious objection :) > > > > > > The latest results as I see them have been copied to > > > https://beta.suse.com/private/mgorman/melt/v5.13-rc5/3-perf-test/sched/sched-avgidle-v1r6/html/dashboard.html > > > They will move from here if the patch is accepted to 5-assembly replacing > > > 3-perf-test. This naming is part of my workflow for evaluating topic > > > branches separetly and then putting them together for another round > > > of testing. > > > > > > NAS shows small differences but NAS would see limited impact from the > > > patch. Specjbb shows small losses and some minor gains which is unfortunate > > > but the workload tends to see small gains and losses all the time. > > > redis is a mixed bag but has some wins. hackbench is the main benefit > > > because it's wakeup intensive and tends to overload machines where deep > > > searches hurt. > > > > > > There are other results in there if you feel like digging around > > > such as sched-core tested with no processes getting tagged with prctl > > > https://beta.suse.com/private/mgorman/melt/v5.13-rc5/5-assembly/sched/sched-schedcore-v1r2/html/dashboard.html > > > > > > > Thanks for the links. It's cool to see what your results dashboard looks like. > > It's really small, what are you plotting in those heat maps? > > > > It's hard for me to publish the results that come from our testing (web based > > on intranet) but we don't see any major differences with this patch. There > > are some gains here and there mostly balanced by some loses. Overall it comes > > out basically as a wash across our main performance test workload. > > > > Ok, that's unfortunate. It's also somewhat surprising but then again, I > don't know what tests were executed. Yes, I know, sorry. I get these really nice reports but they're hard to summarize in text :) The testing consists of NAS (mostly C, some D), stress-ng, libmicro, linpack and stream, specjvm2008, specjbb2005 and a few others across a range of (x86_64) hardware. >From libmicro there was these 2 which stand out exit_100 52584 66975 [ -27.4%] exit_100_nolibc 46831 57395 [ -22.6%] Then some scattered gain and loss in the under +/-10% range. That's on a 2-node Rome. It's a bit worse on a 8-node Rome but with libmicro it's a few nsecs here or there. Here are some pieces from the summary page I pulled out and trimmed as an example: kernel testcase system top % change 5.13.0_rc5.idle_aging NASParallel-2_NUMA_nodes gold-2s-b NASParallel_ua_C_x: 4% NASParallel_sp_C_x: -4% 5.13.0_rc5.idle_aging NASParallel-2_NUMA_nodes amd-epyc2-rome NASParallel_sp_C_x: 6% NASParallel_sp_C_x: -10% 5.13.0_rc5.idle_aging LinpackAndStream-2_NUMA_nod… amd-epyc2-rome Linpack_stream_default: 4% Linpack_linpackd_default: -11% 5.13.0_rc5.idle_aging LinpackAndStream-2_NUMA_nod… gold-2s-b Linpack_linpacks_default: 7% Linpack_linpackd_default: -2% 5.13.0_rc5.idle_aging stress-ng-1_NUMA_nodes gold-1s STRESSngTest_getdent: 11% STRESSngTest_madvise: -15% 5.13.0_rc5.idle_aging Intel_Linpack-8_NUMA_nodes gold-4s-b IntelLinpack_default: 12% IntelLinpack_single: -12% The "gold"s are Intel based. As I said, the perf team reported no real difference one way or the other. >From their perspective this patch is basically neutral. > > > It'll be interesting to see if it effects a sensitive, proprietary perf test > > suite from a European company with a 3 letter name :) > > > > I don't think it's worth the effort if it's failing microbenchmarks at > the moment. Fair enough. I'm sensitive to this one because it can be a real pain to track down minor trade-off differences. And I believe you have been there too... Cheers, Phil > > -- > Mel Gorman > SUSE Labs > --