Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261523AbVCNEyH (ORCPT ); Sun, 13 Mar 2005 23:54:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261526AbVCNEyH (ORCPT ); Sun, 13 Mar 2005 23:54:07 -0500 Received: from www.rapidforum.com ([80.237.244.2]:25062 "HELO rapidforum.com") by vger.kernel.org with SMTP id S261523AbVCNExp (ORCPT ); Sun, 13 Mar 2005 23:53:45 -0500 Message-ID: <423518C7.10207@rapidforum.com> Date: Mon, 14 Mar 2005 05:53:27 +0100 From: Christian Schmid User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8a3) Gecko/20040817 X-Accept-Language: de, en MIME-Version: 1.0 To: Nick Piggin CC: Ben Greear , Andrew Morton , lkml Subject: Re: BUG: Slowdown on 3000 socket-machines tracked down References: <4229E805.3050105@rapidforum.com> <422BAAC6.6040705@candelatech.com> <422BB548.1020906@rapidforum.com> <422BC303.9060907@candelatech.com> <422BE33D.5080904@yahoo.com.au> <422C1D57.9040708@candelatech.com> <422C1EC0.8050106@yahoo.com.au> <422D468C.7060900@candelatech.com> <422DD5A3.7060202@rapidforum.com> <422F8A8A.8010606@candelatech.com> <422F8C58.4000809@rapidforum.com> <422F9259.2010003@candelatech.com> <422F93CE.3060403@rapidforum.com> <20050309211730.24b4fc93.akpm@osdl.org> <4231B95B.6020209@rapidforum.com> <4231ED18.2050804@candelatech.com> <4231F112.60403@rapidforum.com> <1110775215.5131.17.camel@npiggin-nld.site> In-Reply-To: <1110775215.5131.17.camel@npiggin-nld.site> 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 Content-Length: 1623 Lines: 30 >>This effect appeared on 1 task and on 200 tasks. I dont know what it is, but with HT off it doesnt >>appear anymore. The slow-down still appears when lower_zone_protection is set to 0 but the peak at >>80 MB disappeared when set to 1024. I am now running at 95 MB/Sec smoothly. >> > > OK well that is a good result for you. Thanks for sticking with it. > Unfortunately you'll probably not want to test any patches on your > production system, so the cause of the problem will be difficult to > fix. > > I am working on patches which improve HT performance in some > situations though, so with luck they will cure your problems too. > Basically I think SMP "balancing" is too aggressive - and this may > explain why 2.6.10 was worse for you, it had patches to *increase* > the aggressiveness of balancing. > > The other thing that worries me is your need for lower_zone_protection. > I think this may be due to unbalanced highmem vs lowmem reclaim. It > would be interesting to know if those patches I sent you improve this. > They certainly improve reclaim balancing for me... but again I guess > you'll be reluctant to do much experimentation :\ I have tested your patch and unfortunately on 2.6.11 it didnt change anything :( I reported this before, or do you mean something else? I am of course willing to test patches as I do not want to stick with 2.6.10 forever. - 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/