Lee, you didn't say what version of MPE/iX you were running on, so here's
a generalization.  As of 5.0, the situations where a CS process can
preempt a DS process are much fewer.  It's one of the reasons why the
timeslice for the DS queue was shortened by default to 200 instead of the
2000 it had been at on 4.0 and earlier.  I don't remember the new
conditions offhand -- my notes are back at work.  Basically though, the
old trick of putting intensive processes in the DS queue doesn't work as
well on 5.0 because the CS processes typically can't preempt the DS
process.  I'd check the quantum and timeslice on the DS queue to make sure
it isn't too long.

Good luck!

Debby ;)

####################################################################
Debby Gray
[log in to unmask]  (work)
  Sunnyvale, CA                             [log in to unmask]
       (personal)
Me?  Opinions?  If no one else will claim them, neither will I...
####################################################################