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=-2.2 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 A41FDC433FF for ; Tue, 6 Aug 2019 14:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75CAF20818 for ; Tue, 6 Aug 2019 14:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732980AbfHFOR6 (ORCPT ); Tue, 6 Aug 2019 10:17:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54570 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728558AbfHFOR6 (ORCPT ); Tue, 6 Aug 2019 10:17:58 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E176830083ED; Tue, 6 Aug 2019 14:17:56 +0000 (UTC) Received: from pauld.bos.csb (dhcp-17-51.bos.redhat.com [10.18.17.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3C2B55C541; Tue, 6 Aug 2019 14:17:53 +0000 (UTC) Date: Tue, 6 Aug 2019 10:17:51 -0400 From: Phil Auld To: Aaron Lu Cc: Julien Desfossez , "Li, Aubrey" , Aubrey Li , Subhra Mazumdar , Vineeth Remanan Pillai , Nishanth Aravamudan , Peter Zijlstra , Tim Chen , Ingo Molnar , Thomas Gleixner , Paul Turner , Linus Torvalds , Linux List Kernel Mailing , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Kees Cook , Greg Kerr , Valentin Schneider , Mel Gorman , Pawan Gupta , Paolo Bonzini Subject: Re: [RFC PATCH v3 00/16] Core scheduling v3 Message-ID: <20190806141750.GA20858@pauld.bos.csb> References: <20190619183302.GA6775@sinkpad> <20190718100714.GA469@aaronlu> <20190725143003.GA992@aaronlu> <20190726152101.GA27884@sinkpad> <7dc86e3c-aa3f-905f-3745-01181a3b0dac@linux.intel.com> <20190802153715.GA18075@sinkpad> <20190805200914.GD20173@pauld.bos.csb> <20190806135401.GB46757@aaronlu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190806135401.GB46757@aaronlu> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 06 Aug 2019 14:17:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 06, 2019 at 09:54:01PM +0800 Aaron Lu wrote: > On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote: > > Hi, > > > > On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote: > > > We tested both Aaron's and Tim's patches and here are our results. > > > > > > Test setup: > > > - 2 1-thread sysbench, one running the cpu benchmark, the other one the > > > mem benchmark > > > - both started at the same time > > > - both are pinned on the same core (2 hardware threads) > > > - 10 30-seconds runs > > > - test script: https://paste.debian.net/plainh/834cf45c > > > - only showing the CPU events/sec (higher is better) > > > - tested 4 tag configurations: > > > - no tag > > > - sysbench mem untagged, sysbench cpu tagged > > > - sysbench mem tagged, sysbench cpu untagged > > > - both tagged with a different tag > > > - "Alone" is the sysbench CPU running alone on the core, no tag > > > - "nosmt" is both sysbench pinned on the same hardware thread, no tag > > > - "Tim's full patchset + sched" is an experiment with Tim's patchset > > > combined with Aaron's "hack patch" to get rid of the remaining deep > > > idle cases > > > - In all test cases, both tasks can run simultaneously (which was not > > > the case without those patches), but the standard deviation is a > > > pretty good indicator of the fairness/consistency. > > > > > > No tag > > > ------ > > > Test Average Stdev > > > Alone 1306.90 0.94 > > > nosmt 649.95 1.44 > > > Aaron's full patchset: 828.15 32.45 > > > Aaron's first 2 patches: 832.12 36.53 > > > Aaron's 3rd patch alone: 864.21 3.68 > > > Tim's full patchset: 852.50 4.11 > > > Tim's full patchset + sched: 852.59 8.25 > > > > > > Sysbench mem untagged, sysbench cpu tagged > > > ------------------------------------------ > > > Test Average Stdev > > > Alone 1306.90 0.94 > > > nosmt 649.95 1.44 > > > Aaron's full patchset: 586.06 1.77 > > > Aaron's first 2 patches: 630.08 47.30 > > > Aaron's 3rd patch alone: 1086.65 246.54 > > > Tim's full patchset: 852.50 4.11 > > > Tim's full patchset + sched: 390.49 15.76 > > > > > > Sysbench mem tagged, sysbench cpu untagged > > > ------------------------------------------ > > > Test Average Stdev > > > Alone 1306.90 0.94 > > > nosmt 649.95 1.44 > > > Aaron's full patchset: 583.77 3.52 > > > Aaron's first 2 patches: 513.63 63.09 > > > Aaron's 3rd patch alone: 1171.23 3.35 > > > Tim's full patchset: 564.04 58.05 > > > Tim's full patchset + sched: 1026.16 49.43 > > > > > > Both sysbench tagged > > > -------------------- > > > Test Average Stdev > > > Alone 1306.90 0.94 > > > nosmt 649.95 1.44 > > > Aaron's full patchset: 582.15 3.75 > > > Aaron's first 2 patches: 561.07 91.61 > > > Aaron's 3rd patch alone: 638.49 231.06 > > > Tim's full patchset: 679.43 70.07 > > > Tim's full patchset + sched: 664.34 210.14 > > > > > > > Sorry if I'm missing something obvious here but with only 2 processes > > of interest shouldn't one tagged and one untagged be about the same > > as both tagged? > > It should. > > > In both cases the 2 sysbenches should not be running on the core at > > the same time. > > Agree. > > > There will be times when oher non-related threads could share the core > > with the untagged one. Is that enough to account for this difference? > > What difference do you mean? I was looking at the above posted numbers. For example: > > > Sysbench mem untagged, sysbench cpu tagged > > > Aaron's 3rd patch alone: 1086.65 246.54 > > > Sysbench mem tagged, sysbench cpu untagged > > > Aaron's 3rd patch alone: 1171.23 3.35 > > > Both sysbench tagged > > > Aaron's 3rd patch alone: 638.49 231.06 Admittedly, there's some high variance on some of those numbers. Cheers, Phil > > Thanks, > Aaron > > > > So in terms of fairness, Aaron's full patchset is the most consistent, but only > > > Tim's patchset performs better than nosmt in some conditions. > > > > > > Of course, this is one of the worst case scenario, as soon as we have > > > multithreaded applications on overcommitted systems, core scheduling performs > > > better than nosmt. > > > > > > Thanks, > > > > > > Julien > > > > -- --