Messages in this thread | | | Date | Tue, 06 Jan 2009 12:40:55 -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: <3ae3aa420901052053m5a410671u13ecccfb7e29260c@mail.gmail.com> "Linas Vepstas" <linasvepstas@gmail.com> writes: : 2009/1/5 john stultz-lkml <johnstul.lkml@gmail.com>: : > On Mon, Jan 5, 2009 at 9:42 AM, Linas Vepstas <linasvepstas@gmail.com> wrote: : > [snip] : >> The long term solution would be write an RFC to extend : >> NTP to also provide TAI information -- e.g. to add a : >> message that indicates the current leap-second offset : >> between UTC and TAI. : > : > I believe Roman has already added this ability: : > http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=153b5d054ac2d98ea0d86504884326b6777f683d;hp=9f14f669d18477fe3df071e2fa4da36c00acee8e : : Well, you're answering a different statment than what : I was talking about -- I wanted to make sure that TAI : information was available via NTP -- this has nothing : to do with the kernel, and would be something available : to all operating systems. : : Anyway -- I'm looking at the patch you reference, and : maybe I'm being dumb -- but -- I think I see a bug. : : case TIME_DEL decrements TAI, but TIME_INS does : not increment it. Instead, there's a lonely increment in : TIME_OOP which seems wrong. ??
No. That's right. The increment doesn't happen until the leap second has happened. The TIME_OOP exists to increment the TAI offset at the right time. The decrement would happen right away, since the second is deleted at the end of :58.
I had to draw lots of pictures when I was working this code out in FreeBSD.
Warner
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