A Cache Coherence Protocol for MIN-Based Multiprocessors With Limited Inclusion

In this paper, we look into a feasible approach to incorporating caches into selected switching ele ments of a multistage interconnection network (MIN)- based multiprocessor. Along with the processor private caches, these switch caches form a two-level cache hi erarchy. Selected switch caches within a particular stage of the MIN are connected by a coherence con trol bus, through which a write-invalidate cache coher ence protocol is maintained. Considering scalability and practicality issues, only limited inclusion between the two cache levels is enforced. A simulation-based performance study is conducted to analyze the impact of the protocol on system performance. Comparison between limited and strict inclusion shows that system performance declines with limited inclusion.