NTPD unable to adjust local clock

Matthew Dillon dillon at apollo.backplane.com
Tue Apr 5 18:45:26 PDT 2005

    I've investigated this a bit more.  OpenBSD's ntpd is just not up to
    snuff.  It has no PLL locking code at all and the result is that the
    timekeeping is constantly out of whack, oscillating back and forth as
    ntpd does its occassional adjtime() based corrections.  If it isn't
    out of whack due to the clock being fast or slow, it's out of whack due
    to the adjtime() call trying to correct 5 minutes worth of creep with a
    single call.  My test boxes are oscillating between -10ms and +25ms of
    error and they have fairly accurate clocks.  Any boxes with inaccurate 
    clocks are going to be hit hard.  A 1 second error is easy to accumulate
    with a clock that is only 0.3% off.

    It's totally unacceptable but I don't have time before the release
    to fix it.

    After the release we are either going to have to go back to the ntpd 
    we had before, or we are going to have to make some major changes to
    OpenBSD's code.  The code looks clean enough that we can probably make
    the required changes, but the work is going to be a bit too involved to
    maintain it as a contrib and a patch set... we'd have to import the
    code for real and maintain it in our tree.

					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>

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