At 05:28 05-01-03, Matt Zimmerman wrote:

>Though, still, waking up once per second should be much less of an impact
>than the 100Hz timer interrupt.

Still, once per second is a lot more than we want. Especially since we don't really 
care what the clock is when the server would otherwise be idle.

I found at http://www.eecis.udel.edu/~ntp/ntp_spool/html/ntpd.html a
description of how the Poll Interval is reduced based on observed jitter
and wander of the clock. It talks about 10's of seconds at least.

I would expect the zSeries TOD clock to be stable enough. The problem may be that the 
operator with his $5 Mickey Mouse watch sets the clock at IPL. It should be enough to 
pick up the real time during boot and continue to use that offset to the TOD. 
Actually, when we have one Linux guest that gets the real time from an ntp server then 
we could use the offset to give each Linux guest its VMDEPOCH (the difference between 
the virtual machine's TOD and the system TOD clock).

Rob

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