A New Method for Computing Page-Fault Rates

When a program is executed in a caching environment, the caching algorithm can be modeled by an associated finite-state automaton. It is assumed that the finite automaton will reach a steady state after processing a long string. By considering the finite automaton, a formula is obtained for the expected page-fault rate in terms of the steady-state probabilities of the automaton. It is possible to derive the steady-state probabilities for the least-recently-used (LRU) algorithm with order-0 and order-1 programs based on a method that describes the page reference strings as regular expressions. The steady-state behavior for caching algorithms with order-1 programs has never been reported before. This analysis method is then applied to obtain an analysis of the caching behavior of a practical storage-and-retrieval algorithm.