OPTIMAL GARBAGE COLLECTION POLICY FOR A MEMORY-MANAGEMENT SYSTEM WITHJOB SWAPPING

A management system for main memory has a great deal of influence on t he efficiency of an entire system. In particular, it is important to m anage a system with multiprogramming that allocates some jobs to main memory and performs their processing at the same time, because the mem ory space after some operations is not in good order due to additions and deletions of jobs; this is called fragmentation. These problems ha ve not yet been solved fundamentally, but some techniques of solving t hem have been studied. This paper formulates a stochastic model of a m emory-management system with functions of compaction and swapping, whi ch are well-known typical techniques of improving efficiency. Using th e theory of reliability, we discuss an optimal policy that reduces was te of memory and time spaces. (C) 1998 Scripta Technica, Electron Comm Jpn Pt 3, 81(10): 9-15; 1998.