Automatic memory hierarchy characterization

Abstract

As the gap between memory speed and processor speed grows, program transformations to improve the peflormance of the memory system have become increasingly important. To understand and optimize memory performance, researchers and practitioners in performance analysis and compiler design require a detailed understanding of the memory hierarchy of the target computer system. Unfortunately, accurate information about the memory hierarchy is not easy to obtain. Vendor microprocessor documentation is ofen incomplete, vague, or worse, erroneous in its description of important on-chip memory parameters. Furthermore, today S computer systems contain complex, multi-level memory systems where the processor is but one component of the memory system. The accuracy of the documentation on the complete memory system is also lacking. This paper describes the implementation of a portable program that automatically determines all of a computer system’s important memory hierarchy parameters. Automatic determination of memory hierarchy parameters is shown to be superior to reliance on vendor data. The robustness and portability of the approach is demonstrated by determining and validating the memory hierarchy parameters for a number of different computer systems, using several of the emerging performance counter application programming inte$aces.