Messages in this thread | | | Date | Mon, 25 Apr 2011 12:28:33 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf: Allow set output buffer for tasks in the same thread group |
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Em Mon, Apr 25, 2011 at 09:40:38PM +0800, Lin Ming escreveu: > On Mon, 2011-04-25 at 01:05 +0800, Peter Zijlstra wrote: > > On Sun, 2011-04-24 at 22:57 +0800, Lin Ming wrote: > > > Currently, kernel only allows an event to redirect its output to other > > > events of the same task. > > > > > > This causes PERF_EVENT_IOC_SET_OUTPUT ioctl fails when an event is > > > trying to redirect its output to other events in the same thread group. > > > > Which is exactly what it should do, you should never be allowed to > > redirect your events to that of another task, since that other task > > might be running on another CPU. > > > > The buffer code strictly assumes no concurrency, therefore its either > > one task or one CPU. > > Well, this is not the right fix, then the perf tool code need to be > fixed.
Yes, I'm working on it.
- Arnaldo
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