Re: [PATCH] x86: enable preemption in delay

From: Thomas Gleixner
Date: Sun May 25 2008 - 16:23:37 EST


On Sun, 25 May 2008, Steven Rostedt wrote:
>
> On Sun, 25 May 2008, Thomas Gleixner wrote:
> >
> > +/*
> > + * 5 usec on a 1GHZ machine. Not necessarily correct, but not too long
> > + * either.
>
> And what happens when we have 10GHz boxes that can do migration in 1us,
> and the delay that is asked for is 2us. We can return early. I don't like
> to place assumptions of this kind that can hurt with future hardware
> enhancements.

Do the math. It's 500ns on a 10GHz machine then. So nothing to worry
about and future proof.

Also when those 10GHZ machines arrive the synchronized TSC should have
finally become reality.

Thanks,

tglx
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