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    SubjectRe: Missing recalculation of scheduler tunables in case of cpu hot add/remove
    Hi!

    > > >>> Aside from that, we probably should put an upper limit in place, as I
    > > >>> guess large cpu count machines get silly large values
    > > >>>
    > > >> I agree to that, but in the code is already an upper limit of
    > > >> 200.000.000 - well we might discuss if that is too low/high.
    > > >>
    > > >
    > > > Yeah, I think we should cap it around the 8-16 CPUs.
    > > >
    > > >
    > > ok for me, driven by that finding I think I have to measure different
    > > kind of scalings anyway, but as usually that takes some time :-/
    > > At least too time much for the discussion & solution of that bug I guess.
    > >
    > > The question for now is what we do on cpu hot add/remove?
    > > Would hooking somewhere in kernel/cpu.c be the right approach - I'm not
    > > quite sure about my own suggestion yet :-).
    >
    > Something like the below might work I suppose, just needs a cleanup and
    > such.

    I see a rather fundamental problem: what if user wants to override
    those values, and wants them stay that way?

    If you do this, suspend/resume will put the old values back AFAICT.

    Pavel
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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