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    Subject[BUG(?)] perf_events: combining multiple tracepoint events into a group produces no counts on member events

    Hi,

    I'm not sure that what I'm seeing is a bug, or was something intentional.

    If I place multiple tracepoint events into a group and measure counts of
    these events on a process, I get no counts for the tracepoint events
    other than the group leader.

    Is this expected behavior?

    It's not clear to me why this should be the case; grouping shouldn't
    have any ill effects on tracepoint events, from my understanding.

    I noticed this because my private version of the perf tool has the event
    group patch https://lkml.org/lkml/2010/11/24/584 as well as the patch
    which fixes the parsing of multiple tracepoint events in the same -e
    switch: https://lkml.org/lkml/2010/11/30/460

    When I dig into the code a bit, I find that each event opens
    successfully, so that's not the problem. If I disable the grouping,
    then I get counts for all of the tracepoint events.

    - Corey



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