An evaluation of directory protocols for medium-scale shared-memory multiprocessors
Shubhendu S. Mukherjee, Mark D. Hill · 1994
This paper considers alternative directory protocols for providing cache coherence in shared-memory multiprocessors with 32 to 128 processors, where the state requirements of DirN may be considered too large. We consider DiriB, i=1,2,4, DirN, Tristate (also called superset), Coarse Vector, and three new protocols. The new protocols—Gray-hardward, Gray-software, Home—are optimizations of Tristate that use gray coding to favor near-neighbor sharing.