Enhanced SpeedStep driver available

[Colin Percival]

  Thanks to everyone who has been sending me data about their
processors (and in particular, the 90nm versions), I now have
a first draft of a Enhanced SpeedStep driver available.  For
people with the appropriate processors (Pentium M only), this
makes it possible to adjust the cpu frequency via a new sysctl
(hw.est_curfreq), and have the cpu voltage adjusted at the
same time.
  I've also put together a very simple control daemon which
reads kern.cp_time every second and adjusts the cpu frequency
based on the fraction of cpu time which is idle.  This increases
my laptop's battery life by around 40%.
  All the code is online at
http://www.daemonology.net/freebsd-est/
  Assuming I don't hear any major bug reports in the next few
days, I'll package these into ports and hopefully get them into
the ports tree in time for 5.3-RELEASE.

Colin Percival