Optimal partitioning of cache memory

• Published in: IEEE transactions on computers Vol. 41; no. 9; pp. 1054 - 1068
• Main Authors: Stone, H.S., Turek, J., Wolf, J.L.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.1992; Institute of Electrical and Electronics Engineers
• Subjects: Algorithm design and analysis; Applied sciences; Cache memory; Computer science; control theory; systems; Exact sciences and technology; Mathematical model; Memory and file management (including protection and security); Memory organisation. Data processing; Software; Steady-state; Terminology; Performance evaluation; Memory hierarchy; Partition method; Optimal allocation; Cache memory; Error rate; Storage system; Replacement; Computer system; Storage allocation; Multilevel system
• ISSN: 0018-9340; 1557-9956
• DOI: 10.1109/12.165388

A model for studying the optimal allocation of cache memory among two or more competing processes is developed and used to show that, for the examples studied, the least recently used (LRU) replacement strategy produces cache allocations that are very close to optimal. It is also shown that when program behavior changes, LRU replacement moves quickly toward the steady-state allocation if it is far from optimal, but converges slowly as the allocation approaches the steady-state allocation. An efficient combinatorial algorithm for determining the optimal steady-state allocation, which, in theory, could be used to reduce the length of the transient, is described. The algorithm generalizes to multilevel cache memories. For multiprogrammed systems, a cache-replacement policy better than LRU replacement is given. The policy increases the memory available to the running process until the allocation reaches a threshold time beyond which the replacement policy does not increase the cache memory allocated to the running process.< >