Re: [LEAPSECS] Precise time over time

From: Poul-Henning Kamp <>
Date: Wed, 10 Aug 2005 20:26:29 +0200

>Simply quoting your decades of experience in implementing real-time
>control systems doesn't cut the meat. Many of us here have exactly that.
>The most striking fault in your line of reasoning is that you live in a
>dreamworld where clocks are never wrong. In the real world of embedded
>systems, leap seconds are a negligible hazard compared to the everyday
>occurance of independent clocks temporarily losing synchronization.

You are missing the point right here in your mostly ad hominem
attack email.

The fact is that embedded systems these days are not stand alone,
but rather well connected and coordinated.

If you want a really disturbing experience, visit a modern robotical
slaughterhouse, and while you are there, observe and think about
what a one second difference could do the the tightly coordinated
choreography of the robots.

The problem with leap seconds is when the systems are in touch with
each other, have synchronized clocks and know it, and then suddenly
some of the systems insert an extra second, and some of them don't...

And you can say all you will about bad impmentations and people deserving
what they get etc, but what you and others feel in that respect does
not change the economics of the situation.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk_at_FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Received on Wed Aug 10 2005 - 11:26:52 PDT

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