Reference: Thapar, M. & Delagi, B. Cache Coherence for Large Scale Shared Memory Multiprocessors. 1990.
Abstract: This paper describes a new solution for the cache coherence problem in large scale shared memory multiprocessors. The protocol is based on a linked list of caches--forming a distributed directory and (to ensure a scalable design) does not require a global broadcast mechanism. Our solution has a lower cost and potentially better performance than current solutions that do not require a global broadcast. The performance of the protocol is more robust when there is contention for the data and for variations in memory technology. further, we do not assume that the network preserves the order of messages. Thus we do not preclude adaptive touting. Our solution also allows an efficient implementation of locks.