Towards general and exact distributed invalidation

Abstract

This paper develops and proves an exact distributed invalidation algorithm for programs with general array accesses, arbitrary parallelisation and migratory writes. We present an efficient constructive algorithm that globally combines locally gathered information to insert coherence calls in such a manner to eliminate invalidation traffic without loss of locality and places the minimal number of coherence calls. Experimental results across a range of benchmarks show that it outperforms hardware based sequential and release consistency approaches and decreases application execution time by up to 12%. This is due to eliminating over 99% of the invalidation traffic in all benchmarks. This dramatic reduction in invalidation traffic reduces the total amount of network traffic by up to 28% and the number of network words transmitted by up to 19%.