Re: [BUG] perf: can not resolve symbols for forked threads

[Peter Zijlstra]

On Tue, Jun 24, 2014 at 06:47:38AM +0000, Tony Lu wrote:
> >That pthread_exit() is the problem; this results in:
> >
> >29456 pts/23   Zl     0:00          |               \_ [hello] <defunct>
> >
> >You want to wait for the threads to complete using pthread_join().
> >
> >I suspect the defunct state hides the process.
> 
> Yes, using pthread_join() can workaround this problem.
> Does that mean the parent thread can not exit before the child threads? It still seems like a perf bug.

So we scan /proc at record start to acquire the state for the existing
tasks, it might be defunct tasks simply aren't there anymore, in which
case there's nothing we can do.

But I haven't checked..

That said, yes it would be nice if we could cure this.
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