ntpq peers formatting needs floating point for time slots.

Gary E. Miller gem at rellim.com
Mon Feb 6 20:46:40 UTC 2017

Yo Matthew!

On Mon, 6 Feb 2017 14:30:43 -0500
Matthew Selsky <Matthew.Selsky at twosigma.com> wrote:

> Does the shm driver need any modifications?

> # ntpshmmon
> ntpshmmon version 1
> #      Name Seen@                Clock                Real                 L Prec
> sample NTP0 1486408132.108158719 1486408132.107249611 1486408132.107249498 0 -20
> sample NTP0 1486408133.108366587 1486408133.107396038 1486408133.107395887 0 -20

> My GPS card comes with a daemon that writes to SHM and it looks like
> it has nanosecond precision.

Yeah, that looks good.

> And maybe the card's daemon needs to be updated to change -20 to -30?

AFAIK ntpd does not use refclock precision.  At least I could not find it.

The only place I can see that precision is used is in ntpd/ntp_proto.c
where is it part of the computation of 'Root Distance (LAMBDA)'.

That calc is in ntp_proto.c in root_dispersion().  Which is NOT called
for refclocks:

        if (!(peer->flags & FLAG_REFCLOCK) && root_distance(peer) >=

OTOH, prolly best to set it to -30, just for grins.  Someday it might
matter, or I might have missed something, or just to seem to do the
right thing.

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at rellim.com  Tel:+1 541 382 8588

	    Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin
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