Implementation and evaluation of directory hints in CC-NUMA multiprocessors

摘要

Directory hints(DHs)help a node in a cache coherent non-uniform memory(CC-NUMA) shared memory multiprocessor to keep track of where valid copies of a memory block may reside. With this information the node can fetch the block directly from those nodes on a read miss(RM). In this way the number of network transactions to serve the miss may be reduced and the expensive directory lookup operation may be removed from the critical path. In this paper, we discuss the issues involved in implementing the DH scheme on a CC-NUMA shared memory multiprocessor and examine one such implementation, which employs a small and fast cache to store the hints.