Compiler-Directed Selective Update Mechanisms for Software Distributed Shared Memory

We estimate the performance gains of a compiler-directed selective update protocol for software distributed shared memory systems. Our base system uses an invalidate-based lazy release consistent protocol. The goal is to reduce the cost of communication, by aggregating messages, by reducing the effects of false sharing, and by eliminating the communication of unnecessary data. We achieve our goal through the use of compiler analysis for prefetching and for further relaxing the consistency model. Well-known compiler techniques, such as regular section analysis, can be adapted to determine data access patterns between synchronization points and supply the necessary information to the runtime system. We propose three selective update techniques - cross-synchronization prefetching, partial update, and consistency elimination, and describe the compiler and runtime support necessary. Cross-synchronization prefetching updates requested data at the time of synchronization without changing the c..