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    SubjectRe: [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints
    (2012/06/01 20:37), Steven Rostedt wrote:
    > On Fri, 2012-06-01 at 13:53 +0900, Masami Hiramatsu wrote:
    >> Hmm, why don't we have two text_poke interfaces for single and
    >> batch? As like dyn_ftrace, since modifying massive points takes
    >> a lot time, so we may have additional kconfig something like
    >> CONFIG_QUICK_BATCH_TEXT_POKE which switches text area to rw while
    >> batch text_poke.
    > I'll be working on patches to consolidate the two after I get everything
    > else working :-) I still need to work on the ftrace kprobe stuff too.
    > I hate having a config option to switch between the two, except for
    > something that can be there if we find the new approach is buggy (like
    > we have with lockdep). That may be a solution for this if we don't agree
    > on one now. That is, bring back stop_machine() when LOCKDEP is enabled.
    > But that should only be a temporary work around not a true fix.
    > I have no problem with having most of the modifying code be shared
    > between text_poke and ftrace. I guess the question is, do we want to do
    > it only with the FIXMAP or do we want text_poke and ftrace to use the rw
    > method for large batches. Heck, we can set a limit. If we are going to
    > update more that 100 locations, we switch the kernel to rw, otherwise we
    > do the FIXMAP update.

    That's reasonable for me :). You can feel free to change/remove
    text_poke_smp_batch which is already old-style interface.


    Masami HIRAMATSU
    Software Platform Research Dept. Linux Technology Center
    Hitachi, Ltd., Yokohama Research Laboratory

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