Partitioned Memory for Unix

[utzoo!decvax!ucbvax!unix-wizards]

>From mike.bmd70 at BRL Wed Oct 28 00:30:37 1981
Greg -

	There is a Naval Postgraduate School Thesis entitled
"The Development of a Partitioned Segmented Memory Manager for the
UNIX Operating System", by Harvey William Emery, Jr, dated June 1976,
which discusses the subject in some detail, and reviews an implementation
which they put together to test their theories.

	[Copies can be had from the Defense Documentation Center, Defense
Logistics Agency, Cameron Station, Alexandria, VA;  Document ADA027251]

"ABSTRACT.  This thesis reports the results of an investigation of the
applicability of pagin and segmentation to memory management in modified
UNIX operating systems on the PDP-11/50....  Two memory managers are
specifically considered:  a partitioned segmented memory manager that was
designed and implemented;  and a simpler, sgemented memory manager that
was designed based on the performance of the partitioned segmented
memory manager.  Recommendations are given for future work."

	The conclusions of the report are rather vague, but seem to
indicate that PSUNIX (their paged swap UNIX) did not cost anything in
terms of performance overall.  It appears that the extra cost of the
repeated PHYSIOs and calls on the driver was offset by the better memory
utilization on the 256Kb 11/50.

	I can try to provide more info on this if people are interested...
					Cheers,
					-Mike