Simulation results for a scalable coherent cache system with incomplete directory state
Joseph E. Hoag, Eugene D. Brooks · Proceedings of the International Conference on Parallel Processing · 1991
A scheme which employs cache grouping and incomplete directory state in order to reduce the cost of maintaining directory state in a shared memory coherent cache system was introduced in earlier work by the authors and others. In this paper we report on detailed simulation studies of a cache grouping scheme employing multistaged network interconnects. We examine the effects of cache group size and support for multicast and combining in the network. We find that the performance of the cache grouping scheme closely approaches that of a full-directory scheme. We also learn that, due to the dominance of one-to-one invalidates in our example applications, the system performance is relatively insensitive to cache group size or the availability of sophisticated multicast and combining features in the network, at least for the relatively small systems we are capable of simulating. 11 refs., 4 figs., 7 tabs.