Re: setting system clock-rate

["David Lord" <netbsd%lordynet.org@localhost>]

On 1 Mar 2009 at 22:47, Kristoff Bonne wrote:

> David,
> 
> 
> (trying out the "nntp"-interface to this mailing-list. I hope this
> message gets posted).
> 
> 
> 
> David Lord schreef:

......

> 
> Thanks for the help, ... but ... euh ... I fear you kind of lost me.
> 
> If I understand correctly, netbsd 4.0.1 (the version I am running) is
> supposed to be "auto-syncronizing" (at least, if it can handle a drift
> that large), but based on what does it do this syncronisation?
> What is the "reference"? The RTC? A ntp-server?

So far as I know the ntp servers are reference

> 
> I'm still pretty new to netbsd, so what exactly do you propose?

First I'd google for motherboard model, netbsd and ntp to see if 
problem has already been solved.

I've now built a 4.0.1 kernel with TIMER_FREQ slow by 3% as shown
by dmesg "i8254" frequency 1163182 Hz but also ACPI-Fast is
unchanged. Guess what?

"ntpdc -c loopinfo" gives:
offset:     -0.0007 s
frequency:  7.398 ppm

That's around same as before so here the TIMER_FREQ change has made 
no difference.

The NetBSD-5.0_BETA system has shown an improvement, now
with:
offset:     -0.0076 s
frequency:  -6.771 ppm

previously:
offset:     -0.0022 s
frequency:  +46.771 ppm

I've just noticed the NetBSD-5 system has an additional timecounter
line in dmesg: "TSC" frequency which has changed with the different
TIMER_FREQ.

What are your timecounter: lines in dmesg? 

Perhaps worth trying a NetBSD-5 GENERIC kernel or turning off acpi 
with NetBSD-4 (not sure if that requires building a kernel).


David

> 
> Do I need to recompile the kernel? I just found the "how to" document so
> I might give that a try tomorrow. I'll post the result here.