Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759778AbcJRK3r (ORCPT ); Tue, 18 Oct 2016 06:29:47 -0400 Received: from mail-qt0-f169.google.com ([209.85.216.169]:36570 "EHLO mail-qt0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759217AbcJRK3j (ORCPT ); Tue, 18 Oct 2016 06:29:39 -0400 Date: Tue, 18 Oct 2016 11:29:37 +0100 From: Matt Fleming To: Vincent Guittot Cc: Wanpeng Li , Peter Zijlstra , Ingo Molnar , "linux-kernel@vger.kernel.org" , Mike Galbraith , Yuyang Du , Dietmar Eggemann Subject: Re: [PATCH] sched/fair: Do not decay new task load on first enqueue Message-ID: <20161018102937.GI16071@codeblueprint.co.uk> References: <20160923115808.2330-1-matt@codeblueprint.co.uk> <20160928101422.GR5016@twins.programming.kicks-ass.net> <20160928193731.GD16071@codeblueprint.co.uk> <20161010100107.GZ16071@codeblueprint.co.uk> <20161010173440.GA28945@linaro.org> <20161011102453.GA16071@codeblueprint.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161011102453.GA16071@codeblueprint.co.uk> User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3138 Lines: 63 On Tue, 11 Oct, at 11:24:53AM, Matt Fleming wrote: > > That's a lot more costly cross-DIE migrations. I think this patch is > along the right lines, but there's something fishy happening on this > box. I wasn't really able to track down why this machine regressed, and the patch shows enough improvement for other boxes that I think it's worth sticking in tip/sched/core. I saw a number of double digit gains for hackbench with this patch. Here's a 4-cpu box that shows improvements in arithmetic mean and some nice improvements to the stddev, hackbench-process-pipes 4.8.0 4.8.0 vanilla find-idle-group-v1r1 Amean 1 3.2580 ( 0.00%) 3.0607 ( 6.06%) Amean 3 8.0387 ( 0.00%) 8.2027 ( -2.04%) Amean 5 12.0507 ( 0.00%) 12.1703 ( -0.99%) Amean 7 16.0027 ( 0.00%) 16.4567 ( -2.84%) Amean 12 26.9030 ( 0.00%) 21.7767 ( 19.05%) Amean 16 33.4127 ( 0.00%) 28.9877 ( 13.24%) Stddev 1 0.1383 ( 0.00%) 0.1787 (-29.22%) Stddev 3 0.1297 ( 0.00%) 0.1677 (-29.29%) Stddev 5 0.5495 ( 0.00%) 0.4549 ( 17.22%) Stddev 7 0.7401 ( 0.00%) 0.6161 ( 16.75%) Stddev 12 2.3187 ( 0.00%) 0.7102 ( 69.37%) Stddev 16 4.0734 ( 0.00%) 2.9364 ( 27.91%) And a 60-cpu box with similar improvements, hackbench-process-sockets 4.8.0 4.8.0 vanilla find-idle-group-v1r1 Amean 1 32.8810 ( 0.00%) 2.0590 ( 93.74%) Amean 4 34.8663 ( 0.00%) 3.3177 ( 90.48%) Amean 7 34.1243 ( 0.00%) 4.3323 ( 87.30%) Amean 12 36.8373 ( 0.00%) 5.3650 ( 85.44%) Amean 21 29.0333 ( 0.00%) 6.0280 ( 79.24%) Amean 30 27.2807 ( 0.00%) 7.2653 ( 73.37%) Amean 48 23.2453 ( 0.00%) 9.9810 ( 57.06%) Amean 79 29.6660 ( 0.00%) 16.6680 ( 43.81%) Amean 110 41.3680 ( 0.00%) 23.1787 ( 43.97%) Amean 141 45.3720 ( 0.00%) 29.4130 ( 35.17%) Amean 172 45.6403 ( 0.00%) 34.3783 ( 24.68%) Amean 203 47.6120 ( 0.00%) 40.0063 ( 15.97%) Amean 234 50.1703 ( 0.00%) 43.4503 ( 13.39%) Amean 240 50.1110 ( 0.00%) 44.4660 ( 11.26%) Stddev 1 0.9714 ( 0.00%) 0.6617 ( 31.88%) Stddev 4 0.4459 ( 0.00%) 0.2943 ( 34.01%) Stddev 7 0.3091 ( 0.00%) 0.2722 ( 11.94%) Stddev 12 0.4603 ( 0.00%) 0.1424 ( 69.05%) Stddev 21 1.3647 ( 0.00%) 0.1566 ( 88.52%) Stddev 30 4.1277 ( 0.00%) 0.0481 ( 98.84%) Stddev 48 1.3689 ( 0.00%) 0.4968 ( 63.71%) Stddev 79 2.0772 ( 0.00%) 0.5309 ( 74.44%) Stddev 110 4.5655 ( 0.00%) 0.1846 ( 95.96%) Stddev 141 4.2637 ( 0.00%) 0.6675 ( 84.34%) Stddev 172 1.5741 ( 0.00%) 1.0242 ( 34.93%) Stddev 203 1.0973 ( 0.00%) 1.4043 (-27.98%) Stddev 234 2.2048 ( 0.00%) 0.8709 ( 60.50%) Stddev 240 1.2849 ( 0.00%) 0.2688 ( 79.08%)