Re: [Ntp] CLOCK_TAI (was NTPv5: big picture)

[Magnus Danielson <[e-mail]>]

Philip,

On 2021-01-04 21:33, Philip Prindeville wrote:
>
>> On Jan 4, 2021, at 1:21 PM, Magnus Danielson <[e-mail]> wrote:
>>
>> Warner,
>>
>> On 2021-01-04 19:29, Warner Losh wrote:
>>>
>>> On Mon, Jan 4, 2021 at 9:34 AM Magnus Danielson <[e-mail]> wrote:
>>>> It's not in NetBSD or FreeBSD.
>>> Unfortunately not. However, that could probably be changed if enough
>>> interest exists.
>>>
>>> There were a number of issues with it in Linux.
>> What issues are these that you refer to?
>>> If there's a clearer definition of what it should be and how things should be updated as leap second knowledge evolves, I'd be happy to get it into FreeBSD...
>> I think that part of the discussion is really not part of NTP WG discussion, but I am sure things can be figured out.
>>
> Again, disagree.  I remember the days of the IETF where (1) a document describing a protocol was required, and (2) a successful “bake-off” demonstrating 3 unrelated interoperating implementations was equally required…

Which is fine if it was relevant, which it really isn't.

The details of how various implementations choose to do things is really
not what the protocol should go into, but it is good that the protocol
and details is done so the implementation becomes feasible. Wither the
kernel use TAI only or can handle various time-scales in parallel is in
my mind to very much degree an implementation detail. There Linux and
BSD can make different approaches with various benefits, and this is why
you want at least two implementations, with assumed different
implementation decisions, to bring it up on the standard track so that
you learned something. There are many ways to implement things, and not
all involve even the kernel to be involved at all. So, I think the
discussion about how the kernel handling things in itself is not the NTP
WG issue, other than showing it's feasible to do. If we agree that it's
feasible, we move on. If someone has an issue for another way to
implement, sure we try to resolve that. The WG should however not
specify how that should be done, and that was the actual question at
hand which I discussed.

> FreeBSD is as good a platform as any to demonstrate one of those implementations.

For sure. That was not the topic at all.

Cheers,
Magnus