Date: Thu, 28 Sep 2006 23:01:25 +0200 (CEST)
From: Roman Zippel <zippel@linux-m68k.org>
To: john stultz <johnstul@us.ibm.com>
cc: lkml <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
       Thomas Gleixner <tglx@linutronix.de>, Andrew Morton <akpm@osdl.org>
Subject: Re: [RFC] exponential update_wall_time
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Hi,

On Wed, 27 Sep 2006, john stultz wrote:

> > You have to keep in mind that ntp time is basically advanced in 1 second 
> > steps (or HZ ticks or freq cycles to be precise) and you have to keep that 
> > property. You can slice that second however you like, but it still has to 
> > add up to 1 second. Right now we slice it into HZ steps, but this can be 
> > rather easily changed now.
> 
> Right off, it seems it would then make sense to make the ntp "ticks" one
> second in length. And set the interval values accordingly.
> 
> However, there might be clocksources that are incapable of running
> freely for a full second w/o overflowing. In that case we would need to
> set the interval values and the ntp tick length accordingly. It seems we
> need some sort of interface to ntp to define that base tick length.
> Would that be ok by you?

I don't see how you want to do this without some rather complex 
calculations. I doubt this will make anything easier.

bye, Roman
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