Kernel PPS processing

Gary E. Miller gem at
Wed Jun 29 23:45:14 UTC 2016

Yo Matthew!

On Wed, 29 Jun 2016 16:38:40 -0400
Matthew Selsky <Matthew.Selsky at> wrote:

> Measuring on this server via ntpq -p we were seeing offsets of +/-
> 3us without either of these two kernel parameters.  With nohz=off,
> the offsets were +/- 1us.  With both kernel parameters we see
> offsets too small for ntpq -p to measure.  

Just rebooted my main Intel chimer with "intel_idle.max_cstate=0".
It was already using HZ=100

Wow.  I thought something was wrong.  My local clock offset (peerstats
file) has always been hanging around 100ppm.  Stable to ±1ppm so I
figured that was normal.

After reboot the local clock offset started at 9ppm and has been slowyly
going down, now under 2ppm.

I made note of these setting in the gpsd-time-service-howto.txt

Anyone got a guess what the equivalent RasPi setting to turn off
power saving would be?

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