On Wed, Nov 9, 2011 at 23:44, Chuck Swiger <cswi...@mac.com> wrote: > On Nov 9, 2011, at 2:47 PM, Chris Albertson wrote: >> That will do little good and maybe some harm. ntpd reads time stamped >> input. Even if this sits in a buffer unprocessed it's OK because the >> critical work, the stamping is done inside an interrupt handler. > > Agreed, Solaris ought to support and be using SO_TIMESTAMP, so it > really doesn't matter whether ntpd itself is running at elevated priority.
Agreed assuming the source of time is another NTP server. >> If you are concerned about offset the solution is to use a good local >> reference clock Not to be confused with the undisciplined LOCAL reference clock ;) However, note SO_TIMESTAMP doesn't help with a non-PPS refclock, in that case elevated priority can help, but I still would never run ntpd at higher priority than the OS interrupt-processing thread(s) (applicable only if the interrupt processing is in fact handled by a scheduled thread, which Chuck seems to suggest is the case for Solaris). > For best timekeeping, also setup PPS discipline. With a PPSAPI refclock, the situation is much like with SO_TIMESTAMP -- there's not much, if any, benefit to running ntpd at elevated priority as the PPS timestamp is taken in the interrupt handler. Cheers, Dave Hart _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
