From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751251AbaHAED0 (ORCPT ); Fri, 1 Aug 2014 00:03:26 -0400 Received: from g4t3425.houston.hp.com ([15.201.208.53]:3239 "EHLO g4t3425.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750703AbaHAEDZ (ORCPT ); Fri, 1 Aug 2014 00:03:25 -0400 Message-ID: <1406865802.4243.3.camel@buesod1.americas.hpqcorp.net> Subject: Re: [LKP] [sched/numa] a43455a1d57: +94.1% proc-vmstat.numa_hint_faults_local From: Davidlohr Bueso To: Aaron Lu Cc: Peter Zijlstra , Rik van Riel , LKML , lkp@01.org, jhladky@redhat.com, Fengguang Wu Date: Thu, 31 Jul 2014 21:03:22 -0700 In-Reply-To: <20140801020330.GA30211@aaronlu.sh.intel.com> References: <53d70ee6.JsUEmW5dWsv8dev+%fengguang.wu@intel.com> <53D72FF5.90908@intel.com> <20140729023940.37b6aebc@annuminas.surriel.com> <20140731104241.GA9918@twins.programming.kicks-ass.net> <20140801020330.GA30211@aaronlu.sh.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-08-01 at 10:03 +0800, Aaron Lu wrote: > On Thu, Jul 31, 2014 at 12:42:41PM +0200, Peter Zijlstra wrote: > > On Tue, Jul 29, 2014 at 02:39:40AM -0400, Rik van Riel wrote: > > > On Tue, 29 Jul 2014 13:24:05 +0800 > > > Aaron Lu wrote: > > > > > > > FYI, we noticed the below changes on > > > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > > > > commit a43455a1d572daf7b730fe12eb747d1e17411365 ("sched/numa: Ensure task_numa_migrate() checks the preferred node") > > > > > > > > ebe06187bf2aec1 a43455a1d572daf7b730fe12e > > > > --------------- ------------------------- > > > > 94500 ~ 3% +115.6% 203711 ~ 6% ivb42/hackbench/50%-threads-pipe > > > > 67745 ~ 4% +64.1% 111174 ~ 5% lkp-snb01/hackbench/50%-threads-socket > > > > 162245 ~ 3% +94.1% 314885 ~ 6% TOTAL proc-vmstat.numa_hint_faults_local > > > > > > Hi Aaron, > > > > > > Jirka Hladky has reported a regression with that changeset as > > > well, and I have already spent some time debugging the issue. > > > > So assuming those numbers above are the difference in > > Yes, they are. > > It means, for commit ebe06187bf2aec1, the number for > num_hint_local_faults is 94500 for ivb42 machine and 67745 for lkp-snb01 > machine. The 3%, 4% following that number means the deviation of the > different runs to their average(we usually run it multiple times to > phase out possible sharp values). We should probably remove that > percentage, as they cause confusion if no detailed explanation and may > not mean much to the commit author and others(if the deviation is big > enough, we should simply drop that result). > > The percentage in the middle is the change between the two commits. > > Another thing is the meaning of the numbers, it doesn't seem that > evident they are for proc-vmstat.numa_hint_faults_local. Maybe something > like this is better? Instead of removing info, why not document what each piece of data represents. Or add headers to the table. etc. Thanks, Davidlohr