-------- In message <556d8c59.9040...@edlmax.com>, Brooks Harris writes:
>> A lot of Windows machines are doing things where you would expect >> people to care about leap-seconds: Nuclear power plants control >> systems, Air Traffic Control computers, Surgery robots, Patient >> Monitors, Power grid disturbance detectors etc. etc. etc. >In many of those uses the PC is not doing the mission critical timing. >No event-driven multitasking OS can do precise timing [...] You're saying this to the bloke who implemented a prototype adaptive optics solution for the ESO ELT on a plain, unmodified FreeBSD kernel ? Anyway, the PC doesn't need to do the RT parts directly in order to mess them up with wrong timestamps. >> But this is not something they are happy about doing, much less >> proud of doing, but weighing the risks of "heterogeneous" leap-second >> handling and the risk of being up to half a second wrong about time >> for most of a day, they picked the second risk. >> >The failures folks are frightened of are bugs evoked by the Leap Second. >At least some of which are just "stupid" bugs, like threading races when >outputting the Leap Second event to the system log, not basic >timekeeping calculation errors. If all parts of the system did POSIX and >NTP correctly the timekeeping would not reflect UTC correctly because >neither POSIX or NTP do that anyway, but the systems wouldn't hang or >crash. As it is they have to "smear" to minimize the problems. Which is like saying that if only 50% of all programmers weren't below the skill-median, we wouldn't have the problem. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs