Performance oriented programming for NUMA architectures

OpenMP is emerging as a viable high-level programming model for shared memory parallel systems. Although it has also been implemented on ccNUMA architectures, it is hard to obtain high performance on such systems, particularly when large numbers of threads are involved. Moreover, it is applicable to NUMA machines only if a software DSM system is present. In this paper, we discuss: various ways in which OpenMP may be used on ccNUMA and NUMA architectures, and evaluate several programming styles on the SGI Origin 2000, and on TreadMarks, a Software Distributed Shared Memory System from Rice University. These results have encouraged us to begin work on a compiler that accepts an extended OpenMP and translates such code to an equivalent version that provides superior performance on both of these platforms.