Competitive management of distributed shared memory

The authors present and analyze algorithms for managing the distributed shared memory present in nonuniform-memory-access multiprocessors and related systems. The competitive properties of these algorithms guarantee that their performance is within a small constant factor of optimal even though they make no use of any information about memory reference patterns. Both hardware and software implementation concerns are covered. A case study of the Mach operating system indicates that integration of these algorithms into operating systems does not pose major problems. On the other hand, hardware support is required to obtain the full functionality of the algorithms. The authors also sketch possible extensions to the algorithms to support additional hardware architectures and software programming models.<>