Abstract: A distributed shared memory multiprocessor system that supports both fine- and coarse- grained interleaving of the shared memory address space. A ceiling mask sets a boundary between the fine-grain interleaved and coarse-grain interleaved memory regions of the distributed shared memory. A method for satisfying a memory access request in a distributed shared memory subsystem of a multiprocessor system having both fine- and coarse-grain interleaved memory segments. Certain low or high order address bits, depending on whether the memory segment is fine- or coarse-grain interleaved, respectively, are used to determine if the memory address is local to a processor node. A method for setting the ceiling mask of a distributed shared memory multiprocessor system to optimize performance of a first application run on a single node and performance of a second application run on a plurality of nodes.

Abstract: A distributed shared memory multiprocessor system that supports both fine- and coarse-grained interleaving of the shared memory address space. A ceiling mask sets a boundary between the fine-grain interleaved and coarse-grain interleaved memory regions of the distributed shared memory. A method for satisfying a memory access request in a distributed shared memory subsystem of a multiprocessor system having both fine- and coarse-grain interleaved memory segments. Certain low or high order address bits, depending on whether the memory segment is fine- or coarse-grain interleaved, respectively, are used to determine if the memory address is local to a processor node. A method for setting the ceiling mask of a distributed shared memory multiprocessor system to optimize performance of a first application run on a single node and performance of a second application run on a plurality of nodes.