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    SubjectRe: [PATCH] perf, x86: catch spurious interrupts after disabling counters
    > On Wed, Sep 15, 2010 at 10:21:10PM +0200, Stephane Eranian wrote:
    > > When you do perf record foo, it's equivalent to
    > > perf record -e cycles:uk -F 1000 foo

    Yes, thanks.

    I am asking because I have observed up to 4 back-to-back nmis from the
    same counter when enabling an event. The period is not yet adjusted.
    We should avoid those short sampling periods in the beginning and
    better start with too long periods. Didn't look at the implementation
    so far. I know this is not easy to handle because this very much
    depends on the event we measure.

    Maybe we start the counter with a delay and then calculate period =
    duration - delay, later decreasing the delay until the frequency is
    adjusted but keeping the total sampling rate more or less constant.

    -Robert

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



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