QUESTION:
> An Informix DBA, who does not subscribe to the group, was wondering if
> anyone knew anything about the following questions:
>
> 1. Is there a kernel parameter of Compaq Tru64 4.0F that controls the
> subsecond granularity ?
> 2. If there is, which fraction digit (the first, the 2nd or the 3rd
> digit...after the second) does the current setting of the alpha server set
> to ?
>
> PS: subsecond granularity means that how precise or frequent the OS
> reports the current time requested by any applications; once every second
> or once every fraction of a second (0.xxx second).
>
ANSWER (From Dr. Thomas Blinn, who else?):
There is a kernel option to build "microtime" support into the
product. It
is not well documented in my opinion, but it's there. Without it,
you get
the basic realtime clock granularity.
The basic realtime clock in Alpha systems "ticks" about once a
millisecond,
getting any more fine-grained timing than that involve interpolation
and
that's somewhat expensive, especially on MP systems, and involves
using
the Alpha chip's instruction counter as a time base (don't ask how I
know
this level of detail; I've had to work on code in that area during
my time
as a UNIX developer and project leader).
Received on Wed Jul 11 2001 - 16:08:51 NZST