Realtime process CPU starvation

[Dieter BSD]

For those who care, I'm running
kern.sched.name: ULE

My (feeble) understanding is that the scheduler mostly looks at cpu
time, and processes doing i/o actually get a bump *up* in priority,
since because of the way hardware worked in the late 1970s-early 1980s
(PDP-11, VAX, ...) the i/o got useful work done while using very little
cpu time.  As a result, jobs that do a lot of i/o can receive more
than their fair share of cpu time.  And nice(1) (even rtprio and idprio)
may not have much effect on jobs that are i/o bound.  Some form of
ionice is sorely needed.