Messages in this thread | | | Date | Fri, 11 Jul 2014 15:23:09 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/5] perf: Destroy event's children on task exit |
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On Fri, Jul 11, 2014 at 01:56:19PM +0200, Jiri Olsa wrote: > From: Jiri Olsa <jolsa@redhat.com> > > When task exits we close: > 1) all events that are installed in task > 2) all events owned by task (via file descriptor) > > But we don't close children events of 2) events. Those children > events stay until the child task exits and are useless with the > parent being gone, because we have no way to get to values any > more. > > Plus if the event stays installed in task even with the owner task > gone, it runs the perf callback any time the task forks, for no > real reason. > > Closing all children events events when the owner task of the > parent event is closed.
So I _think_ the reason we didn't do this is because this is potentially very expensive and keeping them around isn't too much bother, they'll die eventually.
But I can't really remember. Ingo any recollections / opinions?
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