From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758561Ab0GBM5P (ORCPT ); Fri, 2 Jul 2010 08:57:15 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:43756 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758356Ab0GBM5O (ORCPT ); Fri, 2 Jul 2010 08:57:14 -0400 Subject: Re: [RFC][PATCH 00/11] perf pmu interface -v2 From: Will Deacon To: Peter Zijlstra Cc: paulus , stephane eranian , Robert Richter , Paul Mundt , Frederic Weisbecker , Cyrill Gorcunov , Lin Ming , Yanmin , Deng-Cheng Zhu , David Miller , linux-kernel@vger.kernel.org In-Reply-To: <1277994970.1917.184.camel@laptop> References: <20100624142804.431553874@chello.nl> <1277464288.26786.3.camel@e102144-lin.cambridge.arm.com> <1277464589.32034.276.camel@twins> <1277476604.24751.8.camel@e102144-lin.cambridge.arm.com> <1277477401.32034.670.camel@twins> <1277994970.1917.184.camel@laptop> Content-Type: text/plain; charset="UTF-8" Date: Fri, 02 Jul 2010 13:55:38 +0100 Message-ID: <1278075338.3154.10.camel@e102144-lin.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 02 Jul 2010 12:55:42.0216 (UTC) FILETIME=[E0EF1080:01CB19E5] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, On Thu, 2010-07-01 at 15:36 +0100, Peter Zijlstra wrote: > On Fri, 2010-06-25 at 16:50 +0200, Peter Zijlstra wrote: > > > Not exactly sure how I could have messed up the ARM architecture code to > > make this happen though... will have a peek. > > I did find a bug in there, not sure it could have been responsible for > this but who knows... > > Pushed out a new git tree with the below delta folded in. > I had a look at this yesterday and discovered a bug in the ARM backend code, which I've posted a patch for to ALKML: http://lists.infradead.org/pipermail/linux-arm-kernel/2010-July/019461.html Unfortunately, with this applied and your latest changes I still get 0 from pinned hardware counters: # perf stat -r 5 -e cycles -e instructions -e cs -e faults -e branches -a -- git status Performance counter stats for 'git status' (5 runs): 0 cycles ( +- nan% ) 0 instructions # 0.000 IPC ( +- nan% ) 88447 context-switches ( +- 12.624% ) 13647 page-faults ( +- 0.015% ) 0 branches ( +- nan% ) The changes you've made to arch/arm/kernel/perf_event.c look sane. If I get some time I'll try and dig deeper. Will