[time-nuts] Re: PPS latency? User vs kernel mode

[folkert]

> > In FreeBSD you get all that for free:
> >
> >         https://papers.freebsd.org/2002/phk-timecounters.files/timecounter.pdf
> >
> 
> "It is painfully obvious that the interrupt latency is the dominant
> noise factor in PPS timestamping in the second case."

I wrote something this evening that just busy-loops waiting for a
raising edge and then writes down the current time to feed that to ntp.

My testing is of course still running but the program is at 
https://github.com/folkertvanheusden/poll-pps

I delete it if it is not working so be quick :-)