From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757429AbXKPQfj (ORCPT ); Fri, 16 Nov 2007 11:35:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751946AbXKPQfb (ORCPT ); Fri, 16 Nov 2007 11:35:31 -0500 Received: from g1t0028.austin.hp.com ([15.216.28.35]:36444 "EHLO g1t0028.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798AbXKPQfa (ORCPT ); Fri, 16 Nov 2007 11:35:30 -0500 X-Greylist: delayed 559 seconds by postgrey-1.27 at vger.kernel.org; Fri, 16 Nov 2007 11:35:30 EST Message-ID: <473DC496.6010805@hp.com> Date: Fri, 16 Nov 2007 11:25:58 -0500 From: "Alan D. Brunelle" User-Agent: Thunderbird 2.0.0.6 (X11/20071022) MIME-Version: 1.0 To: Andrew Morton Cc: Rik van Riel , arjan@infradead.org, jens.axboe@oracle.com, mingo@elte.hu, linux-kernel@vger.kernel.org Subject: Re: [patch] Give kjournald a IOPRIO_CLASS_RT io priority References: <20071015104647.14e60bc5@laptopd505.fenrus.org> <20071015114738.6b5a25c7.akpm@linux-foundation.org> <20071015161315.4fe18e07@bree.surriel.com> <20071015141236.62b075c6.akpm@linux-foundation.org> <473B18BA.5000709@hp.com> <20071114091451.d4b110db.akpm@linux-foundation.org> In-Reply-To: <20071114091451.d4b110db.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Here are the results for the latest tests, some notes: o The machine actually has 8GiB of RAM, so the tests still may end up using (some) page cache. (But at least it was the same for both kernels! :-) ) o Sorry the results took so long - the updated tree size caused the runs to take > 12 hours... o The longer runs seemed to bring down the standard deviation a bit, although they are still quite large. o 10 runs per test (read large file, read a tree, overwrite large file), with averages presented. o 1st 4 columns (min, avg, max, std dev) refer to the average run lengths for the tests - real time, in seconds o The last 3 columns are extracted from iostat results over the course of the whole run. o The read a tree test certainly stands out - the other 2 large file manipulations have the two kernels within a couple of percent, but the read a tree test has Arjan's patch taking about 47%(!) longer on average. The increased %iowait & %system time in all 3 cases is interesting. Read large file: Kernel Min Avg Max Std Dev %user %system %iowait -------------------------------------------------------------- base : 201.6 215.1 275.5 22.8 0.26% 4.69% 33.54% arjan: 198.0 210.3 261.5 18.5 0.33% 10.24% 54.00% Read a tree: Kernel Min Avg Max Std Dev %user %system %iowait -------------------------------------------------------------- base : 3518.2 4631.3 5991.3 784.6 0.19% 3.29% 23.56% arjan: 5731.6 6849.8 7777.4 731.6 0.32% 9.90% 52.70% Overwrite large file: Kernel Min Avg Max Std Dev %user %system %iowait -------------------------------------------------------------- base : 104.2 147.7 239.5 38.4 0.02% 0.05% 1.08% arjan: 106.2 149.7 239.2 38.4 0.25% 0.79% 14.97% Let me know if there is anything else I can do to elaborate, or if you have suggestions for further testing. Alan