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 efficient distributed shared memory on a massively parallel processor. It provides a memory coherency control scheme called the hierarchical bit-map directory to achieve cost effective 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 configuration of the RDT router chip is also discussed. 1 Introduction JUMP-1 is a massively parallel processor prototype developed by collaboration between 7 Japanese universities[4]. The major goal of this project is to establish techniques for building an efficient distributed shared memory on a massively parallel processor. For this purpose, a sophisticated methodology called Strategic Memory System (SMS) is proposed [11][4]. The cache direct..