Hybrid Remote Access Protocol

摘要

The invalidation-based cache coherence protocols used in current CMPs result in inefficient utilization of cache hierarchy in the presence of heavy sharing, since a significant percentage of shared cached data is invalidated soon after it is brought into the private cache. This work presents an analysis of a shared memory cache coherence protocol; based on novel insights from the analysis, we advocate direct remote reads/writes at the shared last-level cache for heavily contended data. Evaluation of our proposed protocol with the Splash2x kernels shows 17 percent geometric mean speedup over traditional MESI coherence and 8.5 percent better performance than prior remote-access proposals.