Re: Linux time code

From: Roman Zippel
Date: Tue Aug 29 2006 - 10:41:41 EST


Hi,

On Mon, 28 Aug 2006, john stultz wrote:

> While its possible to smooth out the leapsecond (which would be useful
> to many folks), the problem is one's system would then diverge from UTC
> for that leapsecond.
>
> The idea he's proposing here is to keep both UTC and UTS as separate
> clock ids, allowing apps to choose which standard (well, I UTS isn't
> quite a standard) they want to follow.

Making it a separate clock would be a bit more complex and I don't know if
it's really worth it for an event that only happens every few years.
We already have everything we need to adjust CLOCK_REALTIME, so it would
be not a real problem to support a timezone UTS.

> I think this would be quite useful, as I've seen a number of requests
> where users don't want the leapsecond inconsistency, and others where
> they need to strictly follow UTC.
>
> I think having TAI would be nice too, but that requires quite a bit of
> infrastructure work (NTP distributing absolute leapsecond counts, etc).

That's the other possibility, as soon as we update the userspace interface
to NTP4, it will also include the TAI value, so it will be available via
adjtimex()/ntp_gettime().

bye, Roman
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