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    SubjectRe: [V3][PATCH 0/7] perf, x86: Implement AMD IBS
    On 04.10.11 04:54:09, Ingo Molnar wrote:
    > So the whole IBS thing looks quite unintegrated to me - and that's
    > partly because the hw is admittedly weird. The way we could perhaps
    > live with it upstream is two conditions:
    >
    > - Testable IBS user-space code a bit more prominently integrated
    > than having to go down into a cellar with no working lights and
    > finding the code on display in tools/perf/Documentation/examples/
    > on the bottom of a locked filing cabinet stuck in a disused
    > lavatory with a sign on the door saying 'Beware of the Leopard.'

    With Lin Ming's patch

    [PATCH v2 6/6] perf tool: Parse general/raw events from sysfs

    you can use perf record to collect IBS samples, e.g.:

    # perf record -e ibs_fetch:r0 -c 100000 -a bash -c someload
    [ perf record: Woken up 3 times to write data ]
    [ perf record: Captured and wrote 2.004 MB perf.data (~87572 samples) ]

    With Stephane's patch

    [PATCH] perf: make perf.data more self-descriptive (v8)

    I could extend perf report to add an IBS parser (I need to know the
    pmu name/type value mapping).

    Do you have something like that in mind?

    As all these patches are still off-tree I would rather prefer to
    decouple the IBS patches from a parser implementation and add it later
    as a single patch series. Hmm?

    > - Only root/privileged users should be able to access it. Right now
    > i think it's root-only due to percpu restrictions, but wanted to
    > mention it that this is an explicit requirement.

    Yes, IBS is restricted to percpu. And percpu requires root privileges
    like all other pmu events. What is your point here?

    -Robert

    --
    Advanced Micro Devices, Inc.
    Operating System Research Center



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