Improving release-consistent shared virtual memory using automatic update

Shared virtual memory is a software technique to provide shared memory on a network of computers without special hardware support. Although several relaxed consistency models and implementations are quite effective, there is still a considerable performance gap between the 'software-only' approach and the hardware approach that uses directory-based caches. Automatic update is a simple communication mechanism, implemented in the SHRIMP multicomputer, that forwards local writes to remote memory transparently. In this paper we propose a new lazy release consistency based protocol, called Automatic Update Release propagate and merge shared memory modifications. We compare the performance of this protocol against a software-only LRC implementation on several Splash-2 applications and show that the AURC approach can substantially improve the performance of LRC. For 16 processors, the average speedup has increased from 5.9 under LRC, to 8.3 under AURC.