Automatic re-nicing of processes under 4.2 bsd

[Mike Muuss]

The renice to 4 after 10 minutes of CPU time could be eliminated
with no consequences other than the obvious.  However, the short-
term scheduling effects are not enough to prevent long-running
CPU or I/O intensive processes started at nice 0 from seriously
impacting interactive performance.  Something else is needed.

I did a really snazzy scheduler for our V6 systems, and some day
if I ever get the time to work on it, I hope to incorporate some
of those ideas into our 4.2 kernel as well.
	Best,
	 -Mike Muuss