"MCCORE::BOLTHOUSE@ti-eg.CSNET".UUCP (03/19/87)
Brent,
The two scenarios I can see where batch users can affect interactive users
are:
1. The batch job does *lots* of very fast I/Os and always gets maximum
dynamic priority boost while an interactive process is compute bound.
I suppose it's possible, but not highly likely.
2. The batch job pages so much that it renders your free and modified lists
useless. We have seen this behavior on a multiprocessor VAX; a nasty
process accesses arrays in the wrong order (from FORTRAN, of course)
and flushes the modified list a couple of times a second. This slows
the system to a crawl. The solution, of course, is to tune the system
to the anticipated workload, not to get rid of batch jobs or compute
bound processes on the attached processor. Giving the batch queue a
large WSEXTENT may help in this regard as well.
Hope this helps.
David L. Bolthouse
Texas Instruments Defense Electronics Information Systems VAX System Support
McKinney, Texas
214.952.2059
Arpa: bolthouse%mccore@ti-eg.csnet