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,UNPARSEABLE_RELAY,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 16D15C433FF for ; Tue, 6 Aug 2019 13:54:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5E7A20C01 for ; Tue, 6 Aug 2019 13:54:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732325AbfHFNyH (ORCPT ); Tue, 6 Aug 2019 09:54:07 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:44074 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726373AbfHFNyH (ORCPT ); Tue, 6 Aug 2019 09:54:07 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07417;MF=aaron.lu@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0TYpDuCR_1565099641; Received: from aaronlu(mailfrom:aaron.lu@linux.alibaba.com fp:SMTPD_---0TYpDuCR_1565099641) by smtp.aliyun-inc.com(127.0.0.1); Tue, 06 Aug 2019 21:54:03 +0800 Date: Tue, 6 Aug 2019 21:54:01 +0800 From: Aaron Lu To: Phil Auld 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: <20190806135401.GB46757@aaronlu> References: <20190613032246.GA17752@sinkpad> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190805200914.GD20173@pauld.bos.csb> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? 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 > > --