Re: [PATCH 1/2] Dynamic Tick: Prevent clocksource wrapping duringidle

From: Thomas Gleixner
Date: Wed May 27 2009 - 16:33:15 EST


On Wed, 27 May 2009, john stultz wrote:
> > Why do you want to recalculate the whole stuff over and over ?
> >
> > That computation can be done when the clock source is initialized or
> > any fundamental change of the clock parameters happens.
> >
> > Stick that value into the clocksource struct and just read it out.
>
> Sigh.
>
> I was hoping to avoid hanging another bit of junk off of the clocksource
> struct.

Sure, but buying that 8 bytes with Einsteinian insanity is nuts.

> But I guess we could compute that value on registration and keep it
> around. Changes to mult could effect things, but should be well within
> the 6% safety net we give ourselves.

That was my thought as well, but even if we have to go to 12% it's way
better than doing repeated nonsense on the way to idle.

Thanks,

tglx
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