[lkml]   [2005]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: NTP leap second question
    On 14 Sep 2005 at 11:54, john stultz wrote:

    > On Wed, 2005-09-14 at 11:39 -0700, George Anzinger wrote:
    > > It appears that a leap second is scheduled. One of our customers is
    > > concerened about his application around this. Could one of you NTP
    > > wizards help me to understand NTP a bit better.
    > First: I'm not an NTP wizard by any means, but I'll see if I can't help.
    > > First, I wonder if we suppressed the leap second insert and time then
    > > became out of sync by a second, would NTP "creap" the time back in sync
    > > or would the one second out of sync cause it to quit?
    > The ntpd's slew-bound is .125s I believe, so a second offset would cause
    > ntpd to adjust the time using stime()/settimeofday(). You could run ntpd
    > with the -x option which forces it to always slew the clock. This
    > however could cause the initial sync to take quite some time.
    > > Assuming NTP would do the "creap" thing, is there a way to tell NTP not
    > > to insert the leap second?
    > If I recall, leapsecond implementations are a pretty contentious issue.
    > Some folks have suggested having the kernels note the leapsecond and
    > slew the clock internally. This sounds nicer then just adding or

    No! Never slew a leap second: It will take too long! It's all over after one
    second. If you slew, you time will be incorrect for an extended time.


    > removing a second, but I do not know how that would affect synchronizing
    > between a number of systems. So I'll defer the larger discussion to the
    > real NTP wizards.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-09-15 08:53    [W:0.022 / U:5.308 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site