K 10
svn:author
V 5
markm
K 8
svn:date
V 27
2000-11-21T19:55:21.000000Z
K 7
svn:log
V 516
Add a consistent API to a feature that most modern CPUs have; a fast
counter register in-CPU.

This is to be used as a fast "timer", where linearity is more important
than time, and multiple lines in the linearity caused by multiple CPUs
in an SMP machine is not a problem.

This adds no code whatsoever to the FreeBSD kernel until it is actually
used, and then as a single-instruction inline routine (except for the
80386 and 80486 where it is some more inline code around nanotime(9).

Reviewed by:	bde, kris, jhb

END