Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759484AbZDQC3y (ORCPT ); Thu, 16 Apr 2009 22:29:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756718AbZDQC3o (ORCPT ); Thu, 16 Apr 2009 22:29:44 -0400 Received: from mx2.redhat.com ([66.187.237.31]:38662 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753672AbZDQC3n (ORCPT ); Thu, 16 Apr 2009 22:29:43 -0400 Date: Thu, 16 Apr 2009 22:28:51 -0400 From: Vivek Goyal To: Ryo Tsuruta Cc: agk@redhat.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org, Nauman Rafique , Fernando Luis =?iso-8859-1?Q?V=E1zquez?= Cao , Andrea Righi , Jens Axboe , Balbir Singh , Moyer Jeff Moyer , Morton Andrew Morton Subject: Re: dm-ioband: Test results. Message-ID: <20090417022851.GC23152@redhat.com> References: <20090413.130552.226792299.ryov@valinux.co.jp> <20090416205720.GI8896@redhat.com> <20090417021139.GB23152@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090417021139.GB23152@redhat.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 Content-Length: 2645 Lines: 80 On Thu, Apr 16, 2009 at 10:11:39PM -0400, Vivek Goyal wrote: > On Thu, Apr 16, 2009 at 04:57:20PM -0400, Vivek Goyal wrote: > > On Mon, Apr 13, 2009 at 01:05:52PM +0900, Ryo Tsuruta wrote: > > > Hi Alasdair and all, > > > > > > I did more tests on dm-ioband and I've posted the test items and > > > results on my website. The results are very good. > > > http://people.valinux.co.jp/~ryov/dm-ioband/test/test-items.xls > > > > > > I hope someone will test dm-ioband and report back to the dm-devel > > > mailing list. > > > > > > > Ok, one more test. This time to show that with single queue and FIFO > dispatch a writer can easily starve the reader. > > I have created two partitions /dev/sda1 and /dev/sda2. Two ioband devices > ioband1 and ioband2 on /dev/sda1 and /dev/sda2 respectively with weights > 40 and 20. > > I am launching an aggressive writer dd with prio 7 (Best effort) and a > reader with prio 0 (Best effort). > > Following is my script. > > **************************************************************** > rm /mnt/sdd1/aggressivewriter > > sync > echo 3 > /proc/sys/vm/drop_caches > > #launch an hostile writer > ionice -c2 -n7 dd if=/dev/zero of=/mnt/sdd1/aggressivewriter bs=4K count=524288 conv=fdatasync & > > # Reader > ionice -c 2 -n 0 dd if=/mnt/sdd1/testzerofile1 of=/dev/null & > wait $! > echo "reader finished" > ********************************************************************** More results. Same reader writer test as above, the only variation I have done is change the class of reader to RT from BE. ionice -c 1 -n 0 dd if=/mnt/sdd1/testzerofile1 of=/dev/null & Even chaning the class of reader does not help. Writer still starves the reader. Without dm-ioband ================= First run 2147483648 bytes (2.1 GB) copied, 43.9096 s, 48.9 MB/s (Reader) reader finished 2147483648 bytes (2.1 GB) copied, 85.9094 s, 25.0 MB/s (Writer) Second run 2147483648 bytes (2.1 GB) copied, 40.2446 s, 53.4 MB/s (Reader) reader finished 2147483648 bytes (2.1 GB) copied, 82.723 s, 26.0 MB/s (Writer) With dm-ioband ============== First run 2147483648 bytes (2.1 GB) copied, 69.0272 s, 31.1 MB/s (Writer) 2147483648 bytes (2.1 GB) copied, 89.3037 s, 24.0 MB/s (Reader) reader finished Second run 2147483648 bytes (2.1 GB) copied, 64.8751 s, 33.1 MB/s (Writer) 2147483648 bytes (2.1 GB) copied, 89.0273 s, 24.1 MB/s (Reader) reader finished Thanks Vivek -- 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/