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From: Corey Ashford <cjashfor@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Stephane Eranian <eranian@google.com>
Subject: [BUG(?)] perf_events: combining multiple tracepoint events into a group produces no counts on member events
Date: Tue, 30 Nov 2010 17:00:16 -0800	[thread overview]
Message-ID: <4CF59E20.1040301@linux.vnet.ibm.com> (raw)


Hi,

I'm not sure that what I'm seeing is a bug, or was something intentional.

If I place multiple tracepoint events into a group and measure counts of 
these events on a process, I get no counts for the tracepoint events 
other than the group leader.

Is this expected behavior?

It's not clear to me why this should be the case; grouping shouldn't 
have any ill effects on tracepoint events, from my understanding.

I noticed this because my private version of the perf tool has the event 
group patch https://lkml.org/lkml/2010/11/24/584 as well as the patch 
which fixes the parsing of multiple tracepoint events in the same -e 
switch: https://lkml.org/lkml/2010/11/30/460

When I dig into the code a bit, I find that each event opens 
successfully, so that's not the problem.  If I disable the grouping, 
then I get counts for all of the tracepoint events.

- Corey


             reply	other threads:[~2010-12-01  1:00 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-01  1:00 Corey Ashford [this message]
2010-12-01 11:46 ` Peter Zijlstra
2010-12-01 12:04   ` Peter Zijlstra
2010-12-01 18:02     ` Frederic Weisbecker
2010-12-01 18:52       ` Peter Zijlstra
2010-12-02 17:56         ` Frederic Weisbecker
2010-12-01 18:29     ` Frederic Weisbecker
2010-12-01 18:37       ` Peter Zijlstra
2010-12-01 19:22   ` Corey Ashford
2010-12-01 19:30     ` Peter Zijlstra
2010-12-02  8:58 ` Corey Ashford
2010-12-09 19:56   ` Peter Zijlstra

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