[ntp:questions] Re: Linux 2.6.15.1 & Oncore M12+ & PPSkit-light - yey

draziw at gmail.com draziw at gmail.com
Mon Mar 27 21:20:48 UTC 2006


Ulrich Windl wrote:
> draziw at gmail.com writes:
>
> > An fyi for those googling keywords, and a quick thanks to Ulrich, Reg
> > and the rest of the npt contributors..
> > I'm happily running again with a 2.6 kernel.  2.6.15.1 +
> > PPSkit-light-alpha-3328m-2.6.15.1.diff +
> > ntp-dev-4.2.0b-rc1-20060322.tar.gz.
>
> Unfortunately that version fails to do "PPSFREQ" (because there's a essential
> kernel interface missing). I think I should know ;-)
>
> >
> > After getting the kernel and patch in, checked with ppsapitest.c that
> > the PPS was appearing.  Rebuilt my ntp with ./configure --enable-ONCORE
> > - and it was up.  Not a lot of cycles yet, but so far things look good
> > to my untrained eye.  (My plan is to pull the other st 1 servers after
> > a bit more testing, and put in a st2 as backup)
> >
> > Cheers,
> > Ryan
> >
> > ntpq -p
> >      remote           refid      st t when poll reach   delay   offset
> > jitter
> > ==============================================================================
> > +time.nist.gov   .ACTS.           1 u   49   64  377   62.821    0.483
> >  0.533
> > -timekeeper.isi. .GPS.            1 u   54   64  377   23.499    1.286
> > 16.040
> > +tick.ucla.edu   .PSC.            1 u   60   64  377   14.682    0.810
> >  0.489
> > -gatekeeper.no-s .GPS.            1 u   46   64  377   40.506   -1.346
> > 13.604
> >  LOCAL(0)        .LOCL.           5 l   50   64  377    0.000    0.000
> >  0.001
> > *GPS_ONCORE(0)   .GPS.            0 l   11   16  377    0.000   -0.001
> >  0.001
> >
> > ntptime
> > ntp_gettime() returns code 0 (OK)
> >   time c7ce033c.0f28a000  Thu, Mar 23 2006 21:33:48.059, (.059214),
> >   maximum error 7489 us, estimated error 3 us
> > ntp_adjtime() returns code 0 (OK)
> >   modes 0x0 (),
> >   offset 0.000 us, frequency -159.136 ppm, interval 4 s,
> >   maximum error 7489 us, estimated error 3 us,
> >   status 0x1 (PLL),
> >   time constant 0, precision 1.000 us, tolerance 496 ppm,
> >   pps frequency -59.230 ppm, stability 0.000 ppm, jitter 0.000 us,
> >   intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
>
> Does the pps frequency ever change? I bet not. You don't even have a
> STA_PPSSIGNAL there! I suggest to read the section on configurng PPS and
> trouble shooting in the NTP FAQ. It's a bit old, but still helpful.

Hi Ulrich - it does change...  Output attached.
ntptime
ntp_gettime() returns code 0 (OK)
  time c7d2d4df.554f0000  Mon, Mar 27 2006 13:17:19.333, (.333237),
  maximum error 993 us, estimated error 1 us
ntp_adjtime() returns code 0 (OK)
  modes 0x0 (),
  offset 1.000 us, frequency -158.380 ppm, interval 4 s,
  maximum error 993 us, estimated error 1 us,
  status 0x1 (PLL),
  time constant 0, precision 1.000 us, tolerance 496 ppm,
  pps frequency -159.438 ppm, stability 0.000 ppm, jitter 0.000 us,
  intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
from ntpq -p
*GPS_ONCORE(0)   .GPS.            0 l    1   16  377    0.000    0.001
 0.001

So is something broken with the PPS freq changing?  With a remote
server connected to 4st 1 servers, one of which is mine, it often picks
mine to update from (*) - (depending on load being put on the dsl
line.)

Thanks,
Ryan

> Regards,
> Ulrich




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