Directory-based cache coherence in large-scale multiprocessors

Abstract

The usefulness of shared-data caches in large-scale multiprocessors, the relative merits of different coherence schemes, and system-level methods for improving directory efficiency are addressed. The research presented is part of an effort to build a high-performance, large-scale multiprocessor. The various classes of cache directory schemes are described, and a method of measuring cache coherence is presented. The various directory schemes are analyzed, and ways of improving the performance of directories are considered. It is found that the best solutions to the cache-coherence problem result from a synergy between a multiprocessor's software and hardware components.