[LEAPSECS] My FOSDEM slides

[Joseph Gwinn]

On Thu, 26 Feb 2015 15:09:01 +0100, Martin Burnicki wrote:
> Hi folks,
> 
> I've been asked off list to make the slides of my presentation at 
> FOSDEM 2015 in Brussels available and post the download link on this 
> list.
> 
> So here it is:
> 
<https://fosdem.org/2015/schedule/event/technical_aspects_of_leap_second_propagation_and_evaluation/>
> 
> See the "Attachment" link.

Very interesting; thanks for posting this.

I have a few questions and comments:

1.  Slide titled "Known Bugs (2)": Has support for negative leap 
seconds been restored in NTP v4?  It wasn't clear.

2.  Slide titled ""Possibilities for Future Improvements (2)":  In the 
wish list for a kernel call to ask if the kernel runs UTC or TAI, a 
couple of issues come to mind.  First, many systems set the GPS 
receiver to emit GPS System Time via NTP (and IRIG), so a GPS System 
Time option may be needed.  Second, we often have the GPS (or PTP 1588) 
receiver to emit GPS System Time, but never share this with downstream 
servers, who are configured for UTC (but strangely the leap seconds 
never come).  The difference between UTC and GPS System Time is handled 
in applications code.  The reason for this approach is so that the bulk 
of the system is free from step discontinuities, and only the 
interfaces need deal with UTC.

Joe Gwinn