From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934080AbYEULJe (ORCPT ); Wed, 21 May 2008 07:09:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760357AbYEULJH (ORCPT ); Wed, 21 May 2008 07:09:07 -0400 Received: from g1t0029.austin.hp.com ([15.216.28.36]:36254 "EHLO g1t0029.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759528AbYEULJG (ORCPT ); Wed, 21 May 2008 07:09:06 -0400 Message-ID: <483402CE.9000706@hp.com> Date: Wed, 21 May 2008 07:09:02 -0400 From: "Alan D. Brunelle" User-Agent: Thunderbird 2.0.0.14 (X11/20080505) MIME-Version: 1.0 To: Peter Zijlstra CC: "linux-kernel@vger.kernel.org" Subject: Re: /proc/lock_stat "stuck" References: <483313DD.2020904@hp.com> <1211361380.6463.63.camel@lappy.programming.kicks-ass.net> In-Reply-To: <1211361380.6463.63.camel@lappy.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra wrote: > On Tue, 2008-05-20 at 14:09 -0400, Alan D. Brunelle wrote: >> I'm attempting to use /proc/lock_stat to gather some information during >> some benchmarking runs, but what I find happens is as follows: >> >> 1. I boot the system - 2.6.26-rc3 kernel + CONFIG_LOCK_STAT=y >> >> 2. I can then look at /proc/lock_stat, and it has valid-looking values >> >> 3. I wait a while, do some stuff, but when I look at /proc/lock_stat >> again the values have not changed. >> >> 4. If I clear the counters - echo 0 > /proc/lock_stat - the counters >> never increase, and no information besides the headers are output when I >> cat /proc/lock_stat. >> >> >> Is there something that one needs to do to get counter updates? > > Did you get lockdep warnings? Those disable all lock debugging, > including lockstat. Hi Peter - Yesterday, during boots I /was/ getting a problem with NVIDIA ck804xrom registration problems - "Unable to register resource" - it did produce a stack trace w/ lock calls in the stack. Since then I've cut /way/ back on my .config, and I don't see that problem anymore, and the lock stats seem to be updating correctly with this new .config. [If I have time later today, I'll go back to the old .config and try to track down the ck804xrom issue.] Thanks for the hint about watching for lockdep issues, Alan