Messages in this thread | | | Date | Thu, 3 Dec 2009 10:12:06 +0100 | From | Pavel Machek <> | Subject | Re: Missing recalculation of scheduler tunables in case of cpu hot add/remove |
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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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