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    SubjectRe: [PATCH 5/8] perf, tool: Add pmu event parse support for branch_sample_type values
    On Wed, Apr 04, 2012 at 09:50:12PM -0700, Stephane Eranian wrote:
    > On Wed, Apr 4, 2012 at 1:21 PM, Jiri Olsa <> wrote:
    > > Adding a support to specify branch_type as a hardcoded term
    > > inside the pmu event definition.
    > >
    > > It is possible to specify pmu event like:
    > >  "cpu/config=1,branch_type=hv|any_ret|1,config2=2/u"
    > >
    > > Following string values could be used as value for branch_type:
    > >  any_call (PERF_SAMPLE_BRANCH_ANY_CALL)
    > >  ind_call (PERF_SAMPLE_BRANCH_IND_CALL)
    > >
    > > Also a number could be specified as value.
    > >
    > Although it would be nice to have, the current kernel sampling
    > buffer layout + perf would not be able to parse the RECORD_SAMPLE
    > if you were to sample different things for different events:
    > perf record -e
    > cpu/event=0xc0,umask=1:branch_type=any/,cpu/event=0x3c,umask=0x1/
    for some reason I thought there might be sense to have multiple branch
    types enabled in a single event.. I misread the code probably

    > Perf report/annotate would not be able to distinguish a RECORD_SAMPLE
    > generated by the first or the second event. That's because the RECORD_SAMPLE
    > fixed header does not contain enough info to determine which event caused the
    > record to be generated. You need to event ID to decode the sample. The event ID
    > gives you the attr struct which gives you the attr->sample_type which drives the
    > layout of the RECORD_SAMPLE variable size body. The event ID is currently
    > saved "somewhere" in the variable-size body of the sample. You have a chicken
    > and egg problem here.

    yep, I'm aware of this.. cool you're preparing fix

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