Messages in this thread | | | Date | Sat, 05 May 2012 12:27:38 -0700 | From | John Stultz <> | Subject | Re: [PATCH 1/1] ntp: advertise correct TAI offset during leap second |
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On 05/05/2012 03:02 AM, Richard Cochran wrote: > On Tue, May 01, 2012 at 08:16:05AM +0200, Richard Cochran wrote: >> On Mon, Apr 30, 2012 at 12:48:22PM -0700, John Stultz wrote: >>> On 04/27/2012 11:17 PM, Richard Cochran wrote: >>>> Wait a minute. If user space manages this variable, then shouldn't the >>>> kernel leave it alone? >>> Right. That's why I'm asking. I actually haven't spent much time >>> looking at how the tai value provided via adjtimex is handled, and I >>> want to make sure its ok if we modify it from the kernel. >> We *are* already modifying it in kernel, but at the wrong time. >> >> I don't know either what ntpd does, but I will find out. >> >> [ But if ntpd just uses adjtimex() to use the kernel as storage for >> variables, then that is really stupid. ] > I took a look at ntp-4.2.6p5, and ntpd unconditionally sets the TAI > offset using MOD_TAI when it thinks the offset has changed. > > But I think it won't hurt if the kernel changes the offset > automatically, since ntpd will just try and set the same value again. Assuming that it doesn't happen right before the tick that adjusts the leapsecond. :) But that's a pre-existing bug and not a reason to block your patch that improves things.
Thanks for the extra due-diligence here!
thanks -john
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