EVALUATION OF A LOCAL STRATEGY FOR HIGH PERFORMANCE MEMORY MANAGEMENT✶

Conventional operating systems, like Silicon Graphics ’ IRIX and IBM’s AIX, adopt a single memory management algorithm. The choice of this algorithm is usually based on its good performance in relation to the set of programs executed in the computer. Some approximation of LRU (least-recently used) is usually adopted. This choice can take to certain situations in that the computer presents a bad performance due to its bad behavior for certain programs. A possible solution for such cases is to enable each program to have a specific management algorithm (local strategy) that is adapted to its memory access pattern. For example, programs with sequential access pattern, such as SOR, should be managed by the algorithm MRU (most-recently used) because its bad performance when managed by LRU. In this strategy it is very important to decide the memory partitioning strategy among the programs in execution in a multiprogramming environment. Our strategy named CAPR (Compiler-Aided Page Replacement) analyze the pattern of memory references from the source program of an application and communicate these characteristics to the operating system that will make the choice of the best management algorithm and memory partitioning strategy