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    SubjectRe: [PATCH] Linux Kernel Markers

    Hello Frank,

    Frank Ch. Eigler wrote:
    > My interpretation of Martin's Monday proposal is that, if implemented,
    > we wouldn't need any of this nop/int3 stuff. If function being
    > instrumented were recompiled on-the-fly, then it could sport plain &
    > direct C-level calls to the instrumentation handlers.

    Absolutely. I guess the length of these threads is just fertile
    ground for misunderstandings. Basically what Hiramatsu-san and
    myself were discussing was just the mechanism for selecting/
    forking in between the uninstrumented function and the instrumented
    one.

    So, to recap:

    If you had 100,000 instrumentation points in the scheduler (obviously
    a totally bogus number here ...) you'd have 2 functions:
    1- one with no instrumentation at all, but with a 5byte filler such
    as the one presented by Hiramatsu-san.
    2- one with the instrumentation.

    Early in the proposal, the mechanics of switching in between "1" and "2"
    seemed to be problematic, but I think with Hiramatsu-san's proposal
    and, on the x86, djprobes, we've got it figured out.

    Let me know if I'm not providing enough detail.

    Thanks,

    Karim

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