Clock fuzzing bugs

Eric S. Raymond esr at
Sun Nov 24 13:55:53 UTC 2019

Hal Murray via devel <devel at>:
> I'm tempted to rip out that stuff.  I haven't quite convinced myself that it 
> isn't doing something important.  Eric?

The clock fuzzing?  It's an interesting question. I've thought about it.

I'm doubtful myself.  The obvious motivation would be to avoid beat
effects from the resolution of the system clock. You and Gary have a
better feel for signal analysis and our error budget than I do, but
for whatever my opinion is worth this seems to me like a mostly
theoretical problem.

We have pretty good visualization tools these days.  Gary, you know
best what normal perfornance looks like under ntpviz.  Would you be
willing to patch-disable fuzzing and see if that induces any
suspicious-looking sawtooth patterns in the graphs?

If we don't see any evidence of beat-induced quantization, I'm willing
to say we drop this code.
		<a href="">Eric S. Raymond</a>

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