Re: [BUG] perf_events: PERF_FORMAT_GROUP not working correctlywhen monitoring another task

[Peter Zijlstra]

On Thu, 2010-05-06 at 13:09 -0700, Corey Ashford wrote:
> The patch works with the test case I provided, but for some reason it 
> breaks the normal operation of the libpfm4 "task" utility.  If I put 
> more than one event in a group, I get zero counts on all but the first 
> event.  That's even if I don't use the PERF_FORMAT_GROUP option.

Bugger,.. weird though, I can't see how it would affect the state before
the counters get detached from their context (exit() / close()).

> So something appears to be messed up.  I will see if I can construct an 
> arch-independent test case which demonstrates the problem.

That would be awesome, thanks!


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