A Lock-Based Cache Coherence Protocol for Scope Consistency

摘要

Directory protocols are widely adopted to maintain cache coherence of distributed shared memory multiprocessors. Although scalable to a certain extent, directory proto- cols are complex enough to prevent it form being used in very large scale multiprocessors with tens of thousands of nodes. This paper proposes a lock-based cache coherence pro- tocol for scope consistency. It does not rely on directory information to maintain cache coherence. Instead, cache coherence is maintained through requiring the releasing pro- cessor of a lock to store all write-notices generated in the associated critical section to the lock and the acquiring processor invalidates or updates its locally cached data copies according to the write notices of the lock.