From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751755AbeFEIqS (ORCPT ); Tue, 5 Jun 2018 04:46:18 -0400 Received: from outbound-smtp16.blacknight.com ([46.22.139.233]:36849 "EHLO outbound-smtp16.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751442AbeFEIqR (ORCPT ); Tue, 5 Jun 2018 04:46:17 -0400 Date: Tue, 5 Jun 2018 09:46:15 +0100 From: Mel Gorman To: Srikar Dronamraju Cc: Ingo Molnar , Peter Zijlstra , LKML , Rik van Riel , Thomas Gleixner Subject: Re: [PATCH 03/19] sched/numa: Simplify load_too_imbalanced Message-ID: <20180605084615.4pzrkqkdt7j6pgym@techsingularity.net> References: <1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com> <1528106428-19992-4-git-send-email-srikar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1528106428-19992-4-git-send-email-srikar@linux.vnet.ibm.com> User-Agent: NeoMutt/20170912 (1.9.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 04, 2018 at 03:30:12PM +0530, Srikar Dronamraju wrote: > Currently load_too_imbalance() cares about the slope of imbalance. > It doesn't care of the direction of the imbalance. > > However this may not work if nodes that are being compared have > dissimilar capacities. Few nodes might have more cores than other nodes > in the system. Also unlike traditional load balance at a NUMA sched > domain, multiple requests to migrate from the same source node to same > destination node may run in parallel. This can cause huge load > imbalance. This is specially true on a larger machines with either large > cores per node or more number of nodes in the system. Hence allow > move/swap only if the imbalance is going to reduce. > > Testcase Time: Min Max Avg StdDev > numa01.sh Real: 516.14 892.41 739.84 151.32 > numa01.sh Sys: 153.16 192.99 177.70 14.58 > numa01.sh User: 39821.04 69528.92 57193.87 10989.48 > numa02.sh Real: 60.91 62.35 61.58 0.63 > numa02.sh Sys: 16.47 26.16 21.20 3.85 > numa02.sh User: 5227.58 5309.61 5265.17 31.04 > numa03.sh Real: 739.07 917.73 795.75 64.45 > numa03.sh Sys: 94.46 136.08 109.48 14.58 > numa03.sh User: 57478.56 72014.09 61764.48 5343.69 > numa04.sh Real: 442.61 715.43 530.31 96.12 > numa04.sh Sys: 224.90 348.63 285.61 48.83 > numa04.sh User: 35836.84 47522.47 40235.41 3985.26 > numa05.sh Real: 386.13 489.17 434.94 43.59 > numa05.sh Sys: 144.29 438.56 278.80 105.78 > numa05.sh User: 33255.86 36890.82 34879.31 1641.98 > > Testcase Time: Min Max Avg StdDev %Change > numa01.sh Real: 435.78 653.81 534.58 83.20 38.39% > numa01.sh Sys: 121.93 187.18 145.90 23.47 21.79% > numa01.sh User: 37082.81 51402.80 43647.60 5409.75 31.03% > numa02.sh Real: 60.64 61.63 61.19 0.40 0.637% > numa02.sh Sys: 14.72 25.68 19.06 4.03 11.22% > numa02.sh User: 5210.95 5266.69 5233.30 20.82 0.608% > numa03.sh Real: 746.51 808.24 780.36 23.88 1.972% > numa03.sh Sys: 97.26 108.48 105.07 4.28 4.197% > numa03.sh User: 58956.30 61397.05 60162.95 1050.82 2.661% > numa04.sh Real: 465.97 519.27 484.81 19.62 9.385% > numa04.sh Sys: 304.43 359.08 334.68 20.64 -14.6% > numa04.sh User: 37544.16 41186.15 39262.44 1314.91 2.478% > numa05.sh Real: 411.57 457.20 433.29 16.58 0.380% > numa05.sh Sys: 230.05 435.48 339.95 67.58 -17.9% > numa05.sh User: 33325.54 36896.31 35637.84 1222.64 -2.12% > > Signed-off-by: Srikar Dronamraju Acked-by: Mel Gorman -- Mel Gorman SUSE Labs