Messages in this thread | | | Subject | Re: [PATCH] perf: Allow set output buffer for tasks in the same thread group | From | Lin Ming <> | Date | Mon, 25 Apr 2011 21:40:38 +0800 |
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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.
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