A new hybrid directory scheme for shared memory multi-processors

It is increasingly popular to adopt DSM systems to maximize parallelism beyond the limits of SMP. Wherein, a proper cache coherence scheme should be efficient at the memory overhead for maintaining the directories because of its significant impact on overall performance of the system. In this paper, we propose a new hybrid directory scheme which reduces the memory overhead of the directory and improves the memory access time by using our new hybrid directory scheme. We evaluate the performance of our proposed scheme by running six applications on an execution-driven simulator (RSIM). The simulation results show that the performance of a system with hybrid directory can achieve close to that of a multiprocessor with bit-vector directory.