[ntp:questions] ntpd wedged again

A C agcarver+ntp at acarver.net
Tue Feb 14 20:07:40 UTC 2012

On 2/14/2012 01:49, David Lord wrote:
> A C wrote:
>> On 2/13/2012 15:44, David Lord wrote:
>>> Recent ntpd is supposed to handle that level of frequency
>>> offset but most of my pcs have had the frequency offset
>>> adjusted to be < 10 ppm which is done when I build a kernel
>>> with "options PPS_SYNC" and "options TIMER_FREQ=119????".
>> This kernel does have PPS_SYNC enabled but I'm not using it right now
>> since I'm still debugging ntpd/libc. I'll start using it next week
>> after I know ntpd will survive a week straight.
>> How do you determine the timer frequency number? Trial and error?
> At one time I could find it in the documentation but
> not when I last did a search.
> AFAIK it was supposed to be self calibrating so the
> ability for adjustment might be dropped. Unfortunately
> the self calibration can be > 50ppm out.
> PC me6000 is using kernel compiled for a different pc:
> me6000 $ dmesg | grep timecounter
> ....
> timecounter: Timecounter "i8254" frequency 1193182 Hz quality 100
> ....

I have timecounter in my dmesg also but it doesn't show up anywhere in 
the kernel configuration for compiling:

# dmesg | grep time
timecounter: Timecounters tick every 10.000 msec
timer0 at mainbus0 ioaddr 0xf3000000 ipl 10: delay constant 18, 
frequency = 1000000 Hz
timecounter: Timecounter "timer-counter" frequency 1000000 Hz quality 100
timecounter: Timecounter "clockinterrupt" frequency 100 Hz quality 0

I'll have to ask the NetBSD people where the value is hiding.

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