OpenMP on Distributed Memory via Global Arrays ∗

This paper discusses a strategy for implementing OpenMP on distributed memory systems that relies on a source-to-source translation from OpenMP to Global Arrays. Global Arrays is a library with routines for managing data that is declared as shared in a user program. It provides a higher level of control over the mapping of such data to the target machine and enables precise specification of the required accesses. We introduce the features of Global Arrays, outline the translation and its challenges and consider how user-level support might enable us to improve this process. Early experiments are discussed. The paper concludes with some ideas for future work to improve the performance of this and other approaches to providing OpenMP on clusters and other distributed memory platforms. 1