From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753761AbZEQNPW (ORCPT ); Sun, 17 May 2009 09:15:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752888AbZEQNPF (ORCPT ); Sun, 17 May 2009 09:15:05 -0400 Received: from mx-out2.daemonmail.net ([216.104.160.39]:49844 "EHLO mx-out2.daemonmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751073AbZEQNPB convert rfc822-to-8bit (ORCPT ); Sun, 17 May 2009 09:15:01 -0400 From: "Michael S. Zick" Reply-To: lkml@morethan.org To: Wu Fengguang Subject: Re: unresponsiveness on linux desktop during file copy Date: Sun, 17 May 2009 08:14:50 -0500 User-Agent: KMail/1.9.9 References: <93655eb70905151007v5f9bb34aj34be4b65ffeb02a4@mail.gmail.com> <93655eb70905162130k13ebd627o5eba2582508a1c07@mail.gmail.com> <20090517045800.GA32723@localhost> In-Reply-To: <20090517045800.GA32723@localhost> Cc: linux-kernel , Christoph Lameter , Ray Lee , Rik van Riel , Satish Eerpini MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200905170814.52776.lkml@morethan.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat May 16 2009, you wrote: > On Sun, May 17, 2009 at 12:30:28PM +0800, Satish Eerpini wrote: > > > I've prepared a rolled up patch for you, run time tested.  It should > > > protect all of the above pages from being evicted by large file copies. > > > > > > The attached patch is for 2.6.29. > > > > I applied the patch , but the number don seem to show much difference > > The numbers listed in your email? No the most relevant numbers are > memory and disk ones. > > For my part, the number of mapped pages keeps stable when there is an > ongoing background file copy: > > % ls -l /b/sparse > -rw-r--r-- 1 root root 98T 2009-04-29 22:38 /b/sparse > % cp /b/sparse /dev/null& > % for i in `seq 1 100`; do grep Mapped /proc/meminfo; sleep 1; done > Mapped: 22764 kB > Mapped: 22796 kB > Mapped: 22756 kB > Mapped: 22716 kB > Mapped: 22800 kB > Mapped: 22788 kB > Mapped: 22804 kB > Mapped: 22808 kB > Mapped: 22748 kB > Mapped: 22708 kB > Mapped: 22916 kB > Mapped: 22944 kB > Mapped: 22944 kB > Mapped: 22944 kB > Mapped: 22944 kB > Mapped: 22944 kB > Mapped: 22832 kB > Mapped: 22812 kB > Mapped: 22812 kB > Mapped: 22792 kB > Mapped: 22772 kB > Mapped: 22860 kB > Mapped: 22860 kB > Mapped: 22748 kB > Mapped: 22808 kB > Mapped: 22868 kB > Mapped: 22956 kB > Mapped: 22956 kB > Mapped: 22832 kB > Mapped: 22832 kB > Mapped: 22980 kB > Mapped: 22980 kB > Mapped: 22980 kB > Mapped: 22980 kB > Mapped: 22872 kB > Mapped: 22872 kB > Mapped: 22900 kB > Mapped: 22792 kB > Mapped: 22920 kB > Mapped: 22812 kB > Mapped: 22812 kB > Mapped: 22752 kB > Mapped: 22864 kB > Mapped: 22972 kB > Mapped: 22860 kB > Mapped: 22796 kB > Mapped: 22900 kB > Mapped: 22888 kB > Mapped: 22888 kB > Mapped: 22888 kB > Mapped: 22764 kB > > > , following are the statistics with the patched kernel, could > > something else be causing the huge iowait, : > > > > Linux 2.6.29 (satish) 05/17/2009 > > > > 09:57:14 AM CPU %user %nice %system %iowait %steal %idle > > 09:57:18 AM all 12.93 0.00 10.25 33.44 0.00 43.38 > > 09:57:21 AM all 13.32 0.00 28.09 24.40 0.00 34.19 > > 09:57:24 AM all 10.79 0.00 4.76 75.56 0.00 8.89 > > 09:57:26 AM all 11.46 0.00 8.01 35.64 0.00 44.90 > > 09:57:30 AM all 11.68 0.00 8.88 35.05 0.00 44.39 > > Average: all 12.03 0.00 11.94 40.81 0.00 35.22 > > The iowait is high. Do you have "iostat -x 5' numbers? > > > and > > > > hdparm -tT /dev/sda > > > > /dev/sda: > > Timing cached reads: 1332 MB in 2.00 seconds = 666.35 MB/sec > > Timing buffered disk reads: 24 MB in 3.32 seconds = 7.23 MB/sec > > That's pretty slow numbers. On my laptop: > > # hdparm -tT /dev/sda > > /dev/sda: > Timing cached reads: 10266 MB in 1.98 seconds = 5188.46 MB/sec > Timing buffered disk reads: 138 MB in 3.01 seconds = 45.90 MB/sec > I see (on 2.6.30-rc6, no patches): # hdparm -tT /dev/sda (The internal, low-power, low performance hdd): /dev/sda: Timing cached reads: 492 MB in 2.00 seconds = 245.83 MB/sec Timing buffered disk reads: 74 MB in 3.05 seconds = 24.26 MB/sec # hdparm -tT /dev/sdb (A Class-6, SDHC card): /dev/sdb: Timing cached reads: 472 MB in 2.01 seconds = 235.28 MB/sec Timing buffered disk reads: 40 MB in 3.13 seconds = 12.79 MB/sec And the only thing going on - (once you deduct the effect of getting this output) - nothing: top - 08:09:25 up 9 min, 1 user, load average: 0.24, 0.40, 0.25 Tasks: 86 total, 1 running, 85 sleeping, 0 stopped, 0 zombie Cpu(s): 2.9%us, 4.2%sy, 0.8%ni, 59.9%id, 32.2%wa, 0.0%hi, 0.1%si, 0.0%st Mem: 447040k total, 242996k used, 204044k free, 73516k buffers Swap: 2199324k total, 0k used, 2199324k free, 79868k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3359 root 20 0 2444 1048 824 R 3.8 0.2 0:00.04 top 3360 root 20 0 3376 888 744 S 1.9 0.2 0:00.01 less 1 root 20 0 3084 1884 564 S 0.0 0.4 0:01.59 init 2 root 15 -5 0 0 0 S 0.0 0.0 0:00.00 kthreadd Mike > Thanks, > Fengguang > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > >