A comparison of two strategies of dynamic data prefetching in software DSM

Abstract

A major overhead of software DSM is the long remote access latency when the accessed page is not in the focal cache. One method for tolerating the remote access latency is to prefetch the pages before they are accessed. This paper compares two methods of dynamic data prefetching-history prefetching, which utilizes the temporal locality of the program to prefetch, and aggregate prefetching, which utilizes the spatial locality of the program to prefetch-on the JIAJIA software DSM. Experiments with eight well-accepted benchmarks and a real application show that both can dramatically reduce the number of remote page faults and the number of messages exchanged. All applications benefit from the prefetching in overall running time, and four achieve a performance improvement of 10%-20%. We then analyze the advantages and disadvantages of the two prefetching strategies. We find that aggregate prefetching may be more efficient than history prefetching for most applications in software DSM systems.