Optimizing directory-based cache coherence on the RAW architecture

Abstract

Caches help reduce the effect of long-latency memory requests, by providing a high speed data-path to local memory. However, in multi-processor systems utilizing shared memory, cache coherence protocols are necessary to ensure sequential consistency. Of the multiple coherence protocols developed, the scalability of directory-based schemes makes them ideal for RAW's architecture [1]. Although one such system has been demonstrated as a proof-of-concept, it lacks the ability to meet the requirements of load-intensive, high performance applications. It further provides the application developer with no programming constructs to easily leverage the system. This thesis further develops shared memory support for RAW, by bringing greater programmability and performance to shared memory applications. In doing so, it reveals that shared memory is a practical programming paradigm for developing parallel applications on the RAW architecture.