From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751734Ab0EHCYx (ORCPT ); Fri, 7 May 2010 22:24:53 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:58952 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750701Ab0EHCYw (ORCPT ); Fri, 7 May 2010 22:24:52 -0400 Message-ID: <4BE4CB71.60702@linux.vnet.ibm.com> Date: Fri, 07 May 2010 19:24:49 -0700 From: Corey Ashford User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: LKML , Peter Zijlstra , Paul Mackerras CC: Stephane Eranian Subject: Re: [BUG] perf_event: when events are grouped, the time enabled / running values are incorrect References: <4BE4C4BF.6020801@linux.vnet.ibm.com> In-Reply-To: <4BE4C4BF.6020801@linux.vnet.ibm.com> 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 On 05/07/2010 06:56 PM, Corey Ashford wrote: > Hi, > > There appears to be a bug in the kernel related to reading up the time > running and enabled values for events that are in a group. The group > leader's time running and time enable values look correct, but all of > the other group members have a zero value for their time running and > time enabled fields. > > This happens only when remote monitoring a process (perhaps only after > it has terminated)... when self monitoring, the time running/enabled > values come out non-zero, and the values are the same for all of the > counters (as one would expect since they can be enabled/disabled > simultaneously). > > I've attached a test case which you can place in the tools/perf > subdirectory and compile with just: > > gcc -o show_re_bug show_re_bug.c I forgot to mention that you should run this with some sort of the load program, like ./show_re_bug md5sum `which gdb` - Corey