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

Miroslav Lichvar <mlichvar@redhat.com> Mon, 04 January 2021 16:44 UTC

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Date: Mon, 04 Jan 2021 17:44:49 +0100
From: Miroslav Lichvar <mlichvar@redhat.com>
To: Magnus Danielson <magnus@rubidium.se>
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Subject: Re: [Ntp] CLOCK_TAI (was NTPv5: big picture)
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On Mon, Jan 04, 2021 at 05:34:21PM +0100, Magnus Danielson wrote:
> > It's been in the Linux kernel for years.
> >        CLOCK_TAI (since Linux 3.10; Linux-specific)
> >               A nonsettable system-wide clock derived from wall-clock
> >               time but ignoring leap seconds.  This clock does not
> >               experience discontinuities and backwards jumps caused by
> >               NTP inserting leap seconds as CLOCK_REALTIME does.
> Considering how long it's been in the kernel, I consider that for most
> Linux systems, it can be used.

The Linux system TAI clock can be read by applications, but there is
no support for timestamping of packets with this clock, i.e. it is
currently not useful for NTP.

-- 
Miroslav Lichvar

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