PhD ThesisHandling a single page fault involves execution of thousands
of instructions, drum rotational delay and is usually so expensive
that if it can be avoided, almost any other cost can be tolerated.
Optimizing operating system performance is usually the main concern
of computer seientists who deal with paged memories. However,
redesigning the algorithm used by a problem program can often result
in a very significant reduction in paging, and hence in program
execution time. The redesigned algorithm frequently does not
satisfy the more conventional efficiency criteria.
A sorting algorithm, Hash Coding and other search algorithms
are considered. Analytic and simulation studies are presented,
and aome modifications are proposed to reduce the number of page
faults produced by data set references. Analysis is in terms of
three of the most commonly used page replacement algorithms
i.e. least recently used, first in first out, and random selection.
The modifications are for the most part relatively minor
and in some cases have appeared elsewhere in the context of searching
on external storage media. The important aspects are the dramatic
performance improvements which are possible, and the fact that
classical internal algorithms are inappropriate for use in a paged
virtual memory system.The Science Research Council:
The University of Newcastle Upon Tyne:
International Business Machines (United Kingdom) Limited.
