From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932204AbYEUJQj (ORCPT ); Wed, 21 May 2008 05:16:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755037AbYEUJQc (ORCPT ); Wed, 21 May 2008 05:16:32 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:59117 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754513AbYEUJQb (ORCPT ); Wed, 21 May 2008 05:16:31 -0400 Subject: Re: /proc/lock_stat "stuck" From: Peter Zijlstra To: "Alan D. Brunelle" Cc: "linux-kernel@vger.kernel.org" In-Reply-To: <483313DD.2020904@hp.com> References: <483313DD.2020904@hp.com> Content-Type: text/plain Date: Wed, 21 May 2008 11:16:20 +0200 Message-Id: <1211361380.6463.63.camel@lappy.programming.kicks-ass.net> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.