Properties of the Working-Set Model
A program's working set W(t,T) at time t is
the set of distinct pages among the T most recently 
referenced pages.  Relations between the average working-set size,
the missing-page rate, and the interreference-interval 
distribution may be derived both from time-average definitions
and from ensemble-average (statistical) 
definitions. An efficient algorithm for estimating these
quantities is given.  The relation to LRU (least 
recently used) paging is characterized.  The independent-reference
model, in which page references are 
statistically independent, is used to assess the effects
to interpage dependencies on working-set size 
observations. Under general assumptions, working-set
size is shown to be normally distributed.
CACM March, 1972
Denning, P. J.
Schwartz, S. C.
