Re: [PATCH] USER_HZ & NTP problems

From: george anzinger (george@mvista.com)
Date: Wed Sep 11 2002 - 17:56:54 EST


Horst von Brand wrote:
>
> Rolf Fokkens <fokkensr@fokkensr.vertis.nl> said:
> > On Tuesday 10 September 2002 08:09, Vojtech Pavlik wrote:
> > > Actually, the clock true frequency is 1193181.8 Hz, although most
> > > manuals say 1.19318 MHz, which, because truncating more digits, also
> > > correct. But 1193180 Hz isn't. If you're trying to count the time
> > > correctly, you should better use 1193182 Hz if staying in integers.
> >
> > I copied the clock frequency from the kernel source, timex.h defines:
> >
> > #define CLOCK_TICK_RATE 1193180
> >
> > If what you're saying is correct, timex.h uses the wrong value as wel I guess.
>
> I'd be _really_ surprised if that number is within 1% (+-11932 or so)
> correct, an error in the last digit (0.0001%) is surely lost.
> --
But it DOES explain why the ACPI pm timer at 3579545 is not
exactly 3 * CLOCK_TICK_RATE. Inquiring minds want to know
:)

-- 
George Anzinger   george@mvista.com
High-res-timers: 
http://sourceforge.net/projects/high-res-timers/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml
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