Hierarchical Bit-Map Directory Schemes on the RDT Interconnection Network for a Massively Parallel Processor JUMP-1

JUMP-1 is currently under development by seven Japanese universities to establish techniques of an e cient distributed shared memory on a massively parallel processor. It provides a memory coherency control scheme called the hierarchical bit-map directory to achieve cost e ective and high performance management of the cache memory. Messages for maintaining cache coherency are transferred through a fat tree on the RDT(Recursive Diagonal Torus) interconnection network. In this report, we discuss on the scheme and examine its performance. The con guration of the RDT router chip is also discussed.