[ntp:questions] Flash 400 on all peers; can't get ntpd to be happy

Rob nomail at example.com
Mon Mar 14 08:47:39 UTC 2011

unruh <unruh at wormhole.physics.ubc.ca> wrote:
> The problem is not the round trip measurement ( although that can be a
> minor problem). The problem is that the rate of the vm clock is not
> consistant, and thus ntp, which adjusts the clock by adjusting the rate
> ( and strongly assumes that that rate changes slowly if it changes)
> cannot adjust if the clock rate keeps changing by large amounts. 

Why do you keep asserting that, while you clearly don't know what you
are talking about?

You keep assuming that the time in the client is measured by number of
CPU cycles, which is of course hogwash.

The time in the client can be determined from a number of sources, and
in Linux you can even select which source the kernel should use for
timekeeping.  The sources selectable depend on the kernel version.

Each of those sources is virtualized, to a more or less good degree.
But your idea that the CPU is scheduled away from the client and then
those sources stop dead and lose time, is completely wrong.

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