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    SubjectRe: [PATCH v5 8/9] x86-64: Emulate legacy vsyscalls
    On 6 Jun 2011 at 17:59, Ingo Molnar wrote:

    > > > FYI, incredible amount of work has gone into making pagefaults as
    > > > fast and scalable as possible.
    > >
    > > i wasn't talking about scalability (it's irrelevant anyway here),
    > > only speed. [...]
    >
    > Which part of "fast and scalable" did you not understand?

    uhm, not sure why you're so worked up here. is it because i said
    'scalability' was completely irrelevant for the nx vsyscall page
    approach? elaborate!

    > Just a couple of days ago i noticed a single cycle inefficiency in
    > the pagefault fastpath, introduced in the 3.0 merge window. I
    > requested (and got) an urgent fix for that:

    so you must have measurements. what's the mentioned page faults take
    in cycles before/after your fix? what's a normal int xx path take?

    > So i ask you again, what is your basis for calling the #PF path on
    > Linux a 'slowpath'? Is Linus's and my word and 5 years of Git history
    > showing that it's optimized as a fastpath not enough proof for you?

    which part of

    > you must have realized by now that slow/fast path in this context were
    > relative to int xx vs. pf processing.

    did you not understand? do you have "Linus's and my word and 5 years of
    Git history" to show that pf processing is seriously that much faster
    than int xx processing?



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