From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424631AbWLHFeK (ORCPT ); Fri, 8 Dec 2006 00:34:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424633AbWLHFeJ (ORCPT ); Fri, 8 Dec 2006 00:34:09 -0500 Received: from smtp43.singnet.com.sg ([165.21.103.151]:34256 "EHLO smtp43.singnet.com.sg" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424631AbWLHFeG (ORCPT ); Fri, 8 Dec 2006 00:34:06 -0500 Message-ID: <4578F982.70506@homeurl.co.uk> Date: Fri, 08 Dec 2006 13:34:58 +0800 From: Bob User-Agent: Thunderbird 1.5.0.8 (Windows/20061025) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Re: Kernel 2.6 SMP very slow with ServerWorks LE Chipset References: <4577AA11.6020906@homeurl.co.uk> <20061207110737.6c506c98@localhost.localdomain> In-Reply-To: <20061207110737.6c506c98@localhost.localdomain> 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 Alan wrote: >> As a test of raw CPU power I've been decompressing the kernel tree, with >> a UP 2.6 kernel this takes about 1m 15s, I don't know if bz2 is >> multithreaded but even if it's not I would expect a slight speed increase >> but in fact with a SMP 2.6 kernel it take 13 ~ 26m, with a SMP 2.4 >> kernel it takes 1m 28s and with a 2.4 UP 1m 35s. > > The 2.4 numbers look correct (slightly slower), the 2.6 numbers do not. > > > Nothing obviously wrong from the traces however. If you pin the bzip to a > given processor do you get different results according to which CPU ? > > (see man taskset for info on the commands) > > If you get very different times on the two processors that will be very > useful information. Mmm CPU 0 in 1m 32s, but I was running things like ps and taskset in another terminal to verify affinity, CPU 1 still hadn't finished in 40m when I killed it. I've downloaded the LFDK mentioned in the other post and will post the results when I have them. Thanks for replying, This is the script I'm using to time decompression nas:~# cat ./cputest.sh date taskset -c 1 nice -n -8 tar -xjf /root/linux-2.6.18.1.tar.bz2 date uname -a rm -r /root/linux-2.6.18.1/ nas:~# both the tar and bzip2 processes have their affinity and priority set by the above command.