Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264372AbTEGXVa (ORCPT ); Wed, 7 May 2003 19:21:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264389AbTEGXVX (ORCPT ); Wed, 7 May 2003 19:21:23 -0400 Received: from pao-ex01.pao.digeo.com ([12.47.58.20]:20528 "EHLO pao-ex01.pao.digeo.com") by vger.kernel.org with ESMTP id S264372AbTEGXTm (ORCPT ); Wed, 7 May 2003 19:19:42 -0400 Date: Wed, 7 May 2003 16:28:30 -0700 From: Andrew Morton To: Joel Becker Cc: linux-kernel@vger.kernel.org Subject: Re: WimMark I report for 2.5.69 Message-Id: <20030507162830.47af1d47.akpm@digeo.com> In-Reply-To: <20030507231919.GA3989@ca-server1.us.oracle.com> References: <20030507175422.GX3989@ca-server1.us.oracle.com> <20030507154150.005db55e.akpm@digeo.com> <20030507231919.GA3989@ca-server1.us.oracle.com> X-Mailer: Sylpheed version 0.8.9 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 07 May 2003 23:32:12.0079 (UTC) FILETIME=[E278F3F0:01C314F0] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1454 Lines: 37 Joel Becker wrote: > > On Wed, May 07, 2003 at 03:41:50PM -0700, Andrew Morton wrote: > > > Runs: 1462.17 1005.78 1995.99 > > > ... > > > This benchmark is sensitive to random system events. > > > > You can say that again. > > > > We need to understand why there is such variation. If we can do that, > > then perhaps we can make those 1.0's and 1.5's go away. > > Some kernels run very very even. Others do not. I suspect that > certain kernel behaviors and changes exacerbate the issues. Correct me if I'm wrong, but this test is largely seek-bound, is it not? Do you monitor the total CPU utilisation during the run? Is it generally low? If so then we're seek-bound. File layout will influence things a lot. Small variations in timing and in CPU scheduler activity could well cause significant dfifferences in file layout. Does the test generate the files on-the-fly, or are they laid out beforehand? Is it possible to fully populate the datafiles before the run, with a single thread of control? That will ensure that each run is working off the same layout and will give a better basis for comparison. It will also tell us that some layout tweaks may be needed. - 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/