From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753235AbeFDNKm (ORCPT ); Mon, 4 Jun 2018 09:10:42 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56152 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753187AbeFDNKk (ORCPT ); Mon, 4 Jun 2018 09:10:40 -0400 Date: Mon, 4 Jun 2018 06:09:34 -0700 From: Srikar Dronamraju To: Peter Zijlstra Cc: Ingo Molnar , LKML , Mel Gorman , Rik van Riel , Thomas Gleixner Subject: Re: [PATCH 05/19] sched/numa: Use task faults only if numa_group is not yet setup Reply-To: Srikar Dronamraju References: <1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com> <1528106428-19992-6-git-send-email-srikar@linux.vnet.ibm.com> <20180604122408.GT12217@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20180604122408.GT12217@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 18060413-0016-0000-0000-000001D784F6 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18060413-0017-0000-0000-0000322A1679 Message-Id: <20180604130934.GC38574@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-04_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=990 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806040156 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Testcase Time: Min Max Avg StdDev %Change > > numa01.sh Real: 478.45 565.90 515.11 30.87 16.29% > > numa01.sh Sys: 207.79 271.04 232.94 21.33 -15.8% > > numa01.sh User: 39763.93 47303.12 43210.73 2644.86 14.04% > > numa02.sh Real: 60.00 61.46 60.78 0.49 0.871% > > numa02.sh Sys: 15.71 25.31 20.69 3.42 17.35% > > numa02.sh User: 5175.92 5265.86 5235.97 32.82 0.464% > > numa03.sh Real: 776.42 834.85 806.01 23.22 -7.47% > > numa03.sh Sys: 114.43 128.75 121.65 5.49 -19.5% > > numa03.sh User: 60773.93 64855.25 62616.91 1576.39 -5.36% > > numa04.sh Real: 456.93 511.95 482.91 20.88 2.930% > > numa04.sh Sys: 178.09 460.89 356.86 94.58 -11.3% > > numa04.sh User: 36312.09 42553.24 39623.21 2247.96 0.246% > > numa05.sh Real: 393.98 493.48 436.61 35.59 0.677% > > numa05.sh Sys: 164.49 329.15 265.87 61.78 38.92% > > numa05.sh User: 33182.65 36654.53 35074.51 1187.71 3.368% > > > > Ideally this change shouldn't have affected performance. > > Ideally you go on here to explain why it does in fact do affect > performance.. :-) I know it looks bad, but I have been unable to figure out why this patch affects performance. I repeated the experiment multiple times to recheck if it was not a one off problem. While there is a variance in different runs, we do see a change in numbers before and after this patch atleast on my machine.