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 99AC8C31E40 for ; Tue, 6 Aug 2019 14:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76BDF20C01 for ; Tue, 6 Aug 2019 14:41:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733084AbfHFOlb (ORCPT ); Tue, 6 Aug 2019 10:41:31 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:39190 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731807AbfHFOlb (ORCPT ); Tue, 6 Aug 2019 10:41:31 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=aaron.lu@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0TYpaznJ_1565102485; Received: from 10.15.232.115(mailfrom:aaron.lu@linux.alibaba.com fp:SMTPD_---0TYpaznJ_1565102485) by smtp.aliyun-inc.com(127.0.0.1); Tue, 06 Aug 2019 22:41:26 +0800 Subject: Re: [RFC PATCH v3 00/16] Core scheduling v3 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 , =?UTF-8?B?RnLDqWTDqXJpYyBXZWlzYmVja2Vy?= , Kees Cook , Greg Kerr , Valentin Schneider , Mel Gorman , Pawan Gupta , Paolo Bonzini 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> <20190806141750.GA20858@pauld.bos.csb> From: Aaron Lu Message-ID: <83904232-dc75-34fa-2cf6-e11739ae7e5c@linux.alibaba.com> Date: Tue, 6 Aug 2019 22:41:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190806141750.GA20858@pauld.bos.csb> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/8/6 22:17, Phil Auld wrote: > 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. The high variance suggests the code having some fairness issues :-) For the test here, I didn't expect the 3rd patch being used alone since the fairness is solved by patch2 and patch3 together.