From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752002AbZEQE7r (ORCPT ); Sun, 17 May 2009 00:59:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750795AbZEQE7h (ORCPT ); Sun, 17 May 2009 00:59:37 -0400 Received: from mga14.intel.com ([143.182.124.37]:48090 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724AbZEQE7g (ORCPT ); Sun, 17 May 2009 00:59:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.41,206,1241420400"; d="scan'208";a="143655486" Date: Sun, 17 May 2009 12:58:00 +0800 From: Wu Fengguang To: Satish Eerpini Cc: Rik van Riel , Ray Lee , Christoph Lameter , linux-kernel Subject: Re: unresponsiveness on linux desktop during file copy Message-ID: <20090517045800.GA32723@localhost> References: <93655eb70905151007v5f9bb34aj34be4b65ffeb02a4@mail.gmail.com> <2c0942db0905151102y4f144437xa02632effccda72c@mail.gmail.com> <2c0942db0905160903i5517d3d6l50fc7457a2629694@mail.gmail.com> <4A0EFA08.4060106@redhat.com> <20090517011906.GA6375@localhost> <93655eb70905161827x34a432ebn4910ee86d9bae30@mail.gmail.com> <20090517020829.GB6809@localhost> <93655eb70905162130k13ebd627o5eba2582508a1c07@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <93655eb70905162130k13ebd627o5eba2582508a1c07@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Thanks, Fengguang