Messages in this thread | | | Date | Wed, 07 Jan 2009 10:39:47 -0700 (MST) | Subject | Re: [ntpwg] Bug: Status/Summary of slashdot leap-second crash on new years 2008-2009 | From | "M. Warner Losh" <> |
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In message: <49642674.9080703@ntp.isc.org> Danny Mayer <mayer@ntp.isc.org> writes: : Why don't you tell us what the real problem is instead of telling us : that you need TAI offset information?
The real problem is that POSIX time_t totally ignores leap seconds. This forces systems that are rolling through a leap second to repeat time, causing time to jump backwards by 1s (or violate POSIX time_t's invariant that midnight time_t is % 86400 == 0). This jump backwards is a pita in the kernel, and violates the assumption that many programs have that time doesn't flow backwards.
The suggestion to solving this would be to tick in TAI time, and force userland to cope with the leapsecond issues. Of course, there's a number of problems with this solution as well, but it feels like it belongs there...
Warner
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