Generalized Working Sets for Segment Reference Strings
The working-set concept is extended for programs
that reference segments of different sizes. 
 The generalized working-set policy (GWS) keeps as its
resident set those segments whose retention costs 
do not exceed their retrieval costs.  The GWS is a model
for the entire class of demand-fetching memory 
policies that satisfy a resident-set inclusion property.
 A generalized optimal policy (GOPT) is also 
defined; at its operating points it minimizes aggregated
retention and swapping costs.  Special cases 
of the cost structure allow GWS and GOPT to simulate
any known stack algorithm, the working set, and 
VMIN.  Efficient procedures for computing demand curves
showing swapping load as a function of memory 
usage are developed for GWS and GOPT policies.  Empirical
data from an actual system are included.
CACM September, 1978
Denning, P.J.
Slutz, D.R.
