From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262048AbUBBXgz (ORCPT ); Mon, 2 Feb 2004 18:36:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262425AbUBBXgz (ORCPT ); Mon, 2 Feb 2004 18:36:55 -0500 Received: from mail-07.iinet.net.au ([203.59.3.39]:4489 "HELO mail.iinet.net.au") by vger.kernel.org with SMTP id S262048AbUBBXgw (ORCPT ); Mon, 2 Feb 2004 18:36:52 -0500 Message-ID: <401EDEF2.6090802@cyberone.com.au> Date: Tue, 03 Feb 2004 10:36:18 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040122 Debian/1.6-1 X-Accept-Language: en MIME-Version: 1.0 To: Philip Martin CC: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs References: <87oesieb75.fsf@codematters.co.uk> <20040201151111.4a6b64c3.akpm@osdl.org> <401D9154.9060903@cyberone.com.au> <87llnm482q.fsf@codematters.co.uk> <401DDCD7.3010902@cyberone.com.au> <401E1131.6030608@cyberone.com.au> <87d68xcoqi.fsf@codematters.co.uk> In-Reply-To: <87d68xcoqi.fsf@codematters.co.uk> 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 Philip Martin wrote: >Nick Piggin writes: > > >>Another thing I just saw - you've got quite a lot of memory in >>buffers which might be something going wrong. >> >>When the build finishes and there is no other activity, can you >>try applying anonymous memory pressure until it starts swapping >>to see if everything gets reclaimed properly? >> > >How do I apply anonymous memory pressure? > > Well just run something that uses a lot of memory and doesn't do much else. Run a few of these if you like: #include #include #define MEMSZ (64 * 1024 * 1024) int main(void) { int i; char *mem = malloc(MEMSZ); for (i = 0; i < MEMSZ; i+=4096) mem[i] = i; sleep(60); return 0; } >>Was each kernel freshly booted and without background activity >>before each compile? >> > >Each kernel was freshly booted. There were a number of daemons >running, and I was running X, but these don't appear to use much >memory or CPU and the network was disconnected. Just after a boot >there is lots of free memory, but in normal operation the machine uses >its memory, so to make it more like normal I ran "find | grep" before >doing the build. Then I ran make clean, make, make clean, make and >took numbers for the second make. > >You can have the numbers straight after a boot as well. In this case >I rebooted, logged in, ran make clean and make -j4. > >I can hear disk activity on this machine. During a 2.4.24 build the >activity happens in short bursts a few seconds apart. During a 2.6.1 >build it sounds as if there is more activity, with each burst of >activity being a little longer. However that just the impression I >get, I haven't tried timing anything, I may be imagining it. > > Thanks. Much the same, isn't it? Can you try booting with the kernel argument: elevator=deadline and see how 2.6 goes? Andrew, any other ideas?