Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753566AbZCIHKJ (ORCPT ); Mon, 9 Mar 2009 03:10:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752234AbZCIHJ5 (ORCPT ); Mon, 9 Mar 2009 03:09:57 -0400 Received: from mga14.intel.com ([143.182.124.37]:12696 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751933AbZCIHJ4 (ORCPT ); Mon, 9 Mar 2009 03:09:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,328,1233561600"; d="scan'208";a="118156928" Subject: Re: [RFC PATCH 00/19] Cleanup and optimise the page allocator V2 From: Lin Ming To: Mel Gorman Cc: Ingo Molnar , "Zhang, Yanmin" , Nick Piggin , Pekka Enberg , Linux Memory Management List , Rik van Riel , KOSAKI Motohiro , Christoph Lameter , Johannes Weiner , Linux Kernel Mailing List , Peter Zijlstra In-Reply-To: <1236328388.11608.35.camel@minggr.sh.intel.com> References: <1235477835-14500-1-git-send-email-mel@csn.ul.ie> <1235639427.11390.11.camel@minggr> <20090226110336.GC32756@csn.ul.ie> <1235647139.16552.34.camel@penberg-laptop> <20090226112232.GE32756@csn.ul.ie> <1235724283.11610.212.camel@minggr> <20090302112122.GC21145@csn.ul.ie> <1236132307.2567.25.camel@ymzhang> <20090304090740.GA27043@wotan.suse.de> <1236218198.2567.119.camel@ymzhang> <20090305103403.GB32407@elte.hu> <1236328388.11608.35.camel@minggr.sh.intel.com> Content-Type: text/plain Date: Mon, 09 Mar 2009 15:03:06 +0800 Message-Id: <1236582186.11608.47.camel@minggr.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4651 Lines: 106 On Fri, 2009-03-06 at 16:33 +0800, Lin Ming wrote: > On Thu, 2009-03-05 at 18:34 +0800, Ingo Molnar wrote: > > * Zhang, Yanmin wrote: > > > > > On Wed, 2009-03-04 at 10:07 +0100, Nick Piggin wrote: > > > > On Wed, Mar 04, 2009 at 10:05:07AM +0800, Zhang, Yanmin wrote: > > > > > On Mon, 2009-03-02 at 11:21 +0000, Mel Gorman wrote: > > > > > > (Added Ingo as a second scheduler guy as there are queries on tg_shares_up) > > > > > > > > > > > > On Fri, Feb 27, 2009 at 04:44:43PM +0800, Lin Ming wrote: > > > > > > > On Thu, 2009-02-26 at 19:22 +0800, Mel Gorman wrote: > > > > > > > > In that case, Lin, could I also get the profiles for UDP-U-4K please so I > > > > > > > > can see how time is being spent and why it might have gotten worse? > > > > > > > > > > > > > > I have done the profiling (oltp and UDP-U-4K) with and without your v2 > > > > > > > patches applied to 2.6.29-rc6. > > > > > > > I also enabled CONFIG_DEBUG_INFO so you can translate address to source > > > > > > > line with addr2line. > > > > > > > > > > > > > > You can download the oprofile data and vmlinux from below link, > > > > > > > http://www.filefactory.com/file/af2330b/ > > > > > > > > > > > > > > > > > > > Perfect, thanks a lot for profiling this. It is a big help in figuring out > > > > > > how the allocator is actually being used for your workloads. > > > > > > > > > > > > The OLTP results had the following things to say about the page allocator. > > > > > In case we might mislead you guys, I want to clarify that here OLTP is > > > > > sysbench (oltp)+mysql, not the famous OLTP which needs lots of disks and big > > > > > memory. > > > > > > > > > > Ma Chinang, another Intel guy, does work on the famous OLTP running. > > > > > > > > OK, so my comments WRT cache sensitivity probably don't apply here, > > > > but probably cache hotness of pages coming out of the allocator > > > > might still be important for this one. > > > Yes. We need check it. > > > > > > > > > > > How many runs are you doing of these tests? > > > We start sysbench with different thread number, for example, 8 12 16 32 64 128 for > > > 4*4 tigerton, then get an average value in case there might be a scalability issue. > > > > > > As for this sysbench oltp testing, we reran it for 7 times on > > > tigerton this week and found the results have fluctuations. > > > Now we could only say there is a trend that the result with > > > the pathces is a little worse than the one without the > > > patches. > > > > Could you try "perfstat -s" perhaps and see whether any other of > > the metrics outside of tx/sec has less natural noise? > > Thanks, I have used "perfstat -s" to collect cache misses data. > > 2.6.29-rc7-tip: tip/perfcounters/core (b5e8acf) > 2.6.29-rc7-tip-mg2: v2 patches applied to tip/perfcounters/core > > I collected 5 times netperf UDP-U-4k data with and without mg-v2 patches > applied to tip/perfcounters/core on a 4p quad-core tigerton machine, as > below > "value" means UDP-U-4k test result. I forgot to mention that below are the results without client/server bind to different cpus. ./netserver ./netperf -t UDP_STREAM -l 60 -H 127.0.0.1 -- -P 15888,12384 -s 32768 -S 32768 -m 4096 > > 2.6.29-rc7-tip > --------------- > value cache misses CPU migrations cachemisses/migrations > 5329.71 391094656 1710 228710 > 5641.59 239552767 2138 112045 > 5580.87 132474745 2172 60992 > 5547.19 86911457 2099 41406 > 5626.38 196751217 2050 95976 > > 2.6.29-rc7-tip-mg2 > ------------------- > value cache misses CPU migrations cachemisses/migrations > 4749.80 649929463 1132 574142 > 4327.06 484100170 1252 386661 > 4649.51 374201508 1489 251310 > 5655.82 405511551 1848 219432 > 5571.58 90222256 2159 41788 > > Lin Ming > > > > > I think a more invariant number might be the ratio of "LLC > > cachemisses" divided by "CPU migrations". > > > > The fluctuation in tx/sec comes from threads bouncing - but you > > can normalize that away by using the cachemisses/migrations > > ration. > > > > Perhaps. It's definitely a difficult thing to measure. > > > > Ingo -- 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/