From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263462AbUBCDpI (ORCPT ); Mon, 2 Feb 2004 22:45:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264542AbUBCDpH (ORCPT ); Mon, 2 Feb 2004 22:45:07 -0500 Received: from fw.osdl.org ([65.172.181.6]:4744 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S263462AbUBCDpE (ORCPT ); Mon, 2 Feb 2004 22:45:04 -0500 Date: Mon, 2 Feb 2004 19:46:26 -0800 From: Andrew Morton To: Philip Martin Cc: linux-kernel@vger.kernel.org, Nick Piggin Subject: Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs Message-Id: <20040202194626.191cbb95.akpm@osdl.org> In-Reply-To: <87oesieb75.fsf@codematters.co.uk> References: <87oesieb75.fsf@codematters.co.uk> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Philip Martin wrote: > > My test is a software build of about 200 source files (written in C) > that I usually build using "nice make -j4". Timing the build on > 2.4.24 I typically get something like > > 242.27user 81.06system 2:44.18elapsed 196%CPU (0avgtext+0avgdata 0maxresident)k > 0inputs+0outputs (1742270major+1942279minor)pagefaults 0swaps > > and on 2.6.1 I get > > 244.08user 116.33system 3:27.40elapsed 173%CPU (0avgtext+0avgdata 0maxresident)k > 0inputs+0outputs (0major+3763670minor)pagefaults 0swaps I didn't notice the increase in system time. Could you generate a kernel profile? Add `profile=1' to the kernel boot command line and run: sudo readprofile -r sudo readprofile -M10 time make -j4 readprofile -n -v -m /boot/System.map | sort -n +2 | tail -40 | tee ~/profile.txt >&2 on both 2.4 and 2.6? Make sure the System.map is appropriate to the currently-running kernel.