From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752845Ab3LYDat (ORCPT ); Tue, 24 Dec 2013 22:30:49 -0500 Received: from mail-pb0-f53.google.com ([209.85.160.53]:49605 "EHLO mail-pb0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752786Ab3LYDao (ORCPT ); Tue, 24 Dec 2013 22:30:44 -0500 Message-ID: <52BA5153.9090008@linaro.org> Date: Wed, 25 Dec 2013 11:30:27 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Fengguang Wu CC: Yuanhan Liu , "Huang, Ying" , lkp@01.org, LKML Subject: Re: [sched] perf-stat.cpu-migrations changes in dd write test References: <20131222003038.GA8932@localhost> <52B7C7C8.20003@linaro.org> <20131223052426.GB31502@localhost> In-Reply-To: <20131223052426.GB31502@localhost> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/23/2013 01:24 PM, Fengguang Wu wrote: > On Mon, Dec 23, 2013 at 01:19:04PM +0800, Alex Shi wrote: >> On 12/22/2013 08:30 AM, fengguang.wu@intel.com wrote: >>> Alex, >>> >>> We noticed some perf-stat.cpu-migrations changes by your commit >> >> Thanks for your wonder testing, Fengguang! >> How many CPU in your system and how many dd task running? > > For the case > > kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > > It's a KVM with 4 CPUs, 16G memory. There are 4 virtual disks, on top > of each disk there runs 10 dd tasks. I don't know much of kvm. Where the data get from, VM guest or VM host? Looks like any guest cpu usage will be counted as user usage in vmstat. and Does the CS and cpu migration reducing cause dd performance increase? > > Thanks, > Fengguang > >>> >>> 6eb8b571283e64e96ca1a91aad085f9e08f857f0 is the first bad commit >>> commit 6eb8b571283e64e96ca1a91aad085f9e08f857f0 >>> Author: Alex Shi >>> Date: Tue Nov 19 20:29:51 2013 +0800 >>> >>> sched: remove rq->cpu_load[load_idx] array >>> >>> Since load_idx effect removed in load balance, we don't need the >>> load_idx decays in scheduler. that will save some process in sched_tick >>> and others places. >>> >>> Signed-off-by: Alex Shi >>> >>> >>> Here are the changed stats comparing to its parent commit: >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 37779 ~40% +115.2% 81288 ~50% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 37779 +115.2% 81288 TOTAL proc-vmstat.pgscan_direct_normal >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.pgscan_direct_normal >>> >>> 160000 ++----------------------------------------------------------------+ >>> | | >>> 140000 ++ O >>> | | >>> 120000 ++ | >>> | O | >>> 100000 ++ | >>> | | >>> 80000 ++ O | >>> | ..* >>> 60000 ++ .... | >>> | .... | >>> 40000 *+............... O .... | >>> O *............... ........*. | >>> 20000 ++-------------------------------*--------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 121579 ~ 6% -50.8% 59852 ~13% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 121579 -50.8% 59852 TOTAL softirqs.SCHED >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: softirqs.SCHED >>> >>> 140000 ++----------------------------------------------------------------+ >>> 130000 ++ ....*........... ....*....... | >>> | ........ .... ........ ...... | >>> 120000 *+... *.... ..| >>> 110000 ++ * >>> | | >>> 100000 ++ | >>> 90000 ++ | >>> 80000 ++ | >>> | | >>> 70000 ++ O O | >>> 60000 ++ O | >>> | O >>> 50000 O+ | >>> 40000 ++----------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 5636 ~ 4% -22.1% 4392 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 5636 -22.1% 4392 TOTAL proc-vmstat.nr_tlb_remote_flush >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.nr_tlb_remote_flush >>> >>> 6500 ++------------------------------------------------------------------+ >>> | | >>> 6000 ++ ........*............ | >>> *........ .... | >>> 5500 ++ O *................*................| >>> | * >>> 5000 ++ O | >>> | | >>> 4500 ++ O | >>> | | >>> 4000 ++ | >>> | O >>> 3500 O+ | >>> | | >>> 3000 ++------------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 5679 ~ 4% -21.9% 4437 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 5679 -21.9% 4437 TOTAL proc-vmstat.nr_tlb_remote_flush_received >>> >>> >>> >>> 6500 ++------------------------------------------------------------------+ >>> | | >>> 6000 ++ ........*........ | >>> *........ ...... | >>> | .. ........*................| >>> 5500 ++ O *........ * >>> | | >>> 5000 ++ O | >>> | | >>> 4500 ++ O | >>> | | >>> | | >>> 4000 ++ | >>> | O >>> 3500 O+------------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 167 ~11% +19.4% 200 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 167 +19.4% 200 TOTAL uptime.idle >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: uptime.idle >>> >>> 220 ++-------------------------------------------------------------------+ >>> | O >>> 210 ++ | >>> 200 O+ O | >>> | ..*..... O | >>> 190 ++ .... O ... | >>> 180 ++ .... .... | >>> | .... .... | >>> 170 *+. . .* >>> 160 ++ *...... .... | >>> | .... ... | >>> 150 ++ .... ... | >>> 140 ++ .. .... | >>> | *. | >>> 130 ++-------------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 154781 ~ 5% -66.8% 51449 ~ 8% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 154781 -66.8% 51449 TOTAL perf-stat.cpu-migrations >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.cpu-migrations >>> >>> 180000 ++----------------------------------------------------------------+ >>> | ....*........... | >>> 160000 ++ ........ .... ........*...............| >>> *.... *........ * >>> 140000 ++ | >>> | | >>> 120000 ++ | >>> | | >>> 100000 ++ | >>> | | >>> 80000 ++ | >>> | | >>> 60000 ++ O | >>> | O O O >>> 40000 O+----------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 1943 ~ 3% -7.8% 1792 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 1943 -7.8% 1792 TOTAL vmstat.system.cs >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: vmstat.system.cs >>> >>> 2050 ++------------------------------------------------------------------+ >>> | ........*................*..... | >>> 2000 ++ .*........ ... | >>> 1950 ++ .... ... | >>> | ... .... | >>> 1900 ++ ... .| >>> 1850 ++.... O O * >>> *. | >>> 1800 ++ O O >>> 1750 ++ | >>> | | >>> 1700 ++ | >>> 1650 O+ | >>> | | >>> 1600 ++------------------------------------------------------------------+ >>> >>> >>> 1de157d718f6494 6eb8b571283e64e96ca1 >>> --------------- ------------------------- >>> 1216177 ~ 3% -9.4% 1101605 ~ 7% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd >>> 1216177 -9.4% 1101605 TOTAL perf-stat.context-switches >>> >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.context-switches >>> >>> 1.3e+06 ++--------------------------------------------------------------+ >>> | ..*............... | >>> 1.25e+06 ++ ...... *...............*....... | >>> | ..... ...... | >>> 1.2e+06 *+. O ..| >>> 1.15e+06 ++ O * >>> | O | >>> 1.1e+06 ++ | >>> | O >>> 1.05e+06 ++ | >>> 1e+06 ++ | >>> | | >>> 950000 O+ | >>> | | >>> 900000 ++--------------------------------------------------------------+ >>> >>> >> >> >> -- >> Thanks >> Alex -- Thanks Alex