Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761520AbYC0W3S (ORCPT ); Thu, 27 Mar 2008 18:29:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757962AbYC0W3J (ORCPT ); Thu, 27 Mar 2008 18:29:09 -0400 Received: from mail.tmr.com ([64.65.253.246]:51377 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754672AbYC0W3I (ORCPT ); Thu, 27 Mar 2008 18:29:08 -0400 Message-ID: <47EC1FC0.7040405@tmr.com> Date: Thu, 27 Mar 2008 18:29:20 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Mike Galbraith CC: Manfred Spraul , paulmck@linux.vnet.ibm.com, Nadia Derbey , Linux Kernel Mailing List , Andrew Morton Subject: Re: Scalability requirements for sysv ipc References: <47E382DB.70503@colorfullife.com> <47E3ADE3.4030304@bull.net> <47E3B924.3000304@colorfullife.com> <20080321141339.GB9618@linux.vnet.ibm.com> <47E3DD8C.4000904@colorfullife.com> <1206164608.3659.11.camel@marge.simson.net> In-Reply-To: <1206164608.3659.11.camel@marge.simson.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2340 Lines: 60 Mike Galbraith wrote: > On Fri, 2008-03-21 at 17:08 +0100, Manfred Spraul wrote: >> Paul E. McKenney wrote: >>> I could give it a spin -- though I would need to be pointed to the >>> patch and the test. >>> >>> >> I'd just compare a recent kernel with something older, pre Fri Oct 19 >> 11:53:44 2007 >> >> Then download ctxbench, run one instance on each core, bound with taskset. >> http://www.tmr.com/%7Epublic/source/ >> (I don't juse ctxbench myself, if it doesn't work then I could post my >> own app. It would be i386 only with RDTSCs inside) > > (test gizmos are always welcome) > > Results for Q6600 box don't look particularly wonderful. > > taskset -c 3 ./ctx -s > > 2.6.24.3 > 3766962 itterations in 9.999845 seconds = 376734/sec > > 2.6.22.18-cfs-v24.1 > 4375920 itterations in 10.006199 seconds = 437330/sec > > for i in 0 1 2 3; do taskset -c $i ./ctx -s& done > > 2.6.22.18-cfs-v24.1 > 4355784 itterations in 10.005670 seconds = 435361/sec > 4396033 itterations in 10.005686 seconds = 439384/sec > 4390027 itterations in 10.006511 seconds = 438739/sec > 4383906 itterations in 10.006834 seconds = 438128/sec > > 2.6.24.3 > 1269937 itterations in 9.999757 seconds = 127006/sec > 1266723 itterations in 9.999663 seconds = 126685/sec > 1267293 itterations in 9.999348 seconds = 126742/sec > 1265793 itterations in 9.999766 seconds = 126592/sec > Glad to see that ctxbench is still useful, I think there's a more recent version I haven't put up, which uses threads rather than processes, but there were similar values generated, so I somewhat lost interest. There was a "round robin" feature to pass the token through more processes, again I didn't find more use for the data. I never tried binding the process to a CPU, in general the affinity code puts one process per CPU under light load, and limits the context switch overhead. It looks as if you are testing only the single CPU (or core) case. -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot -- 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/