Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753804AbZFWGxj (ORCPT ); Tue, 23 Jun 2009 02:53:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751666AbZFWGx3 (ORCPT ); Tue, 23 Jun 2009 02:53:29 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:54839 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986AbZFWGx2 (ORCPT ); Tue, 23 Jun 2009 02:53:28 -0400 Date: Tue, 23 Jun 2009 12:22:42 +0530 From: Balbir Singh To: Vivek Goyal Cc: Jeff Moyer , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, jens.axboe@oracle.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, guijianfeng@cn.fujitsu.com, dhaval@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, jbaron@redhat.com, agk@redhat.com, snitzer@redhat.com, akpm@linux-foundation.org, peterz@infradead.org Subject: Re: [RFC] IO scheduler based io controller (V5) Message-ID: <20090623065242.GI8642@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> <20090621152116.GC3728@balbir.in.ibm.com> <20090622153030.GA15600@redhat.com> <20090622160207.GC15600@redhat.com> <20090622170812.GD15600@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090622170812.GD15600@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: 2695 Lines: 76 * Vivek Goyal [2009-06-22 13:08:12]: > On Mon, Jun 22, 2009 at 12:06:42PM -0400, Jeff Moyer wrote: > > Vivek Goyal writes: > > > > > On Mon, Jun 22, 2009 at 11:40:42AM -0400, Jeff Moyer wrote: > > >> Vivek Goyal writes: > > >> > > >> > On Sun, Jun 21, 2009 at 08:51:16PM +0530, Balbir Singh wrote: > > >> >> * Vivek Goyal [2009-06-19 16:37:18]: > > >> >> > > >> >> > > > >> >> > Hi All, > > >> >> > > > >> >> > Here is the V5 of the IO controller patches generated on top of 2.6.30. > > >> >> [snip] > > >> >> > > >> >> > Testing > > >> >> > ======= > > >> >> > > > >> >> > > >> >> [snip] > > >> >> > > >> >> I've not been reading through the discussions in complete detail, but > > >> >> I see no reference to async reads or aio. In the case of aio, aio > > >> >> presumes the context of the user space process. Could you elaborate on > > >> >> any testing you've done with these cases? > > >> >> > > >> > > > >> > Hi Balbir, > > >> > > > >> > So far I had not done any testing with AIO. I have done some just now. > > >> > Here are the results. > > >> > > > >> > Test1 (AIO reads) > > >> > ================ > > >> > Set up two fio, AIO read jobs in two cgroup with weight 1000 and 500 > > >> > respectively. I am using cfq scheduler. Following are some lines from my test > > >> > script. > > >> > > > >> > =================================================================== > > >> > fio_args="--ioengine=libaio --rw=read --size=512M" > > >> > > >> AIO doesn't make sense without O_DIRECT. > > >> > > > > > > Ok, here are the read results with --direct=1 for reads. In previous posting, > > > writes were already direct. > > > > > > test1 statistics: time=8 16 20796 sectors=8 16 1049648 > > > test2 statistics: time=8 16 10551 sectors=8 16 581160 > > > > > > > > > Not sure why reads are so slow with --direct=1? In the previous test > > > (no direct IO), I had cleared the caches using > > > (echo 3 > /proc/sys/vm/drop_caches) so reads could not have come from page > > > cache? > > > > O_DIRECT bypasses the page cache, and hence the readahead code. Try > > driving deeper queue depths and/or using larger I/O sizes. > > Ok. Thanks. I tried increasing iodepth to 20 and it helped a lot. > > test1 statistics: time=8 16 6672 sectors=8 16 1049656 > test2 statistics: time=8 16 3508 sectors=8 16 583432 > Good to see.. Thanks! -- Balbir -- 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/