From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261373AbTDKSB4 (for ); Fri, 11 Apr 2003 14:01:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261367AbTDKSBz (for ); Fri, 11 Apr 2003 14:01:55 -0400 Received: from e34.co.us.ibm.com ([32.97.110.132]:14775 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S261364AbTDKSBl (for ); Fri, 11 Apr 2003 14:01:41 -0400 Date: Fri, 11 Apr 2003 11:15:14 -0700 From: Hanna Linder Reply-To: Hanna Linder To: Andrew Morton cc: Hanna Linder , linux-kernel@vger.kernel.org Subject: Re: [Lockmeter 2.5] BKL with 51ms hold time, prove me wrong Message-ID: <34680000.1050084914@w-hlinder> In-Reply-To: <20030410185006.5fd88c30.akpm@digeo.com> References: <46950000.1050023701@w-hlinder> <20030410185006.5fd88c30.akpm@digeo.com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --On Thursday, April 10, 2003 06:50:06 PM -0700 Andrew Morton wrote: > I'm a bit surprised that even slow machine like that would take 50 > milliseconds to truncate 128MB of file, but it's not impossible I guess. > Truncate is not really a fastpath. ext3 in -mm doesn't have any lock_kernels > in it. Sure enough. I ported lockmeter to 2.5.67-mm1 and ran the same rmap-test and lo and behold all the ext3 issues went away. However, the one remaining long hold time moved to the top (unmap_vmas): ___________________________________________________________________________________________ System: Linux w-hlinder2 2.5.67-mm1 #1 SMP Fri Apr 11 12:31:38 PDT 2003 i686 SPINLOCKS HOLD WAIT UTIL CON MEAN( MAX ) MEAN( MAX )(% CPU) TOTAL NOWAIT SPIN RJECT NAME 19.2% 2.0us( 49ms) 1.1us(9767us)(0.58%) 5506902 80.8% 16.6% 2.5% *TOTAL* 0.30% 0.00% 0.4us(9728us) 2598us(3751us)(0.01%) 672210 100% 0.00% 0% journal_datalist_lock 0.26% 0.01% 1.1us(9759us) 4116us(9767us)(0.04%) 211510 100% 0.01% 0% kernel_flag 0.00% 10.9% 2.2us( 14us) 1.0us( 1.9us)(0.00%) 137 89.1% 10.9% 0% runqueues 0.00% 42.9% 1.6us( 14us) 1.0us( 1.9us)(0.00%) 35 57.1% 42.9% 0% load_balance+0x138 0.00% 0% 2.3us( 3.9us) 0us 102 100% 0% 0% wake_up_forked_process+0x3c 3.1% 0% 11ms( 49ms) 0us 245 100% 0% 0% unmap_vmas+0x1c0 ------------ Here is the port of lockmeter to the 2.5.67-mm1 kernel. If you would consider putting it in your tree that would be great and I would work on porting the rest of the architectures. http://prdownloads.sourceforge.net/lse/lockmeter1.5-2.5.67-mm1.patch?download Here is also the whole locmeter output of this run if you are interested. http://prdownloads.sourceforge.net/lse/lockstat-mm1.rmapm?download Thanks a lot! Hanna Linder IBM Linux Technology Center hannal@us.ibm.com