Portable parallel programming for the dynamic load balancing of unstructured grid applications

The ability to dynamically adapt an unstructured grid (or mesh) is a powerful tool for solving computational prob-lems with evolving physical features; however, an efficient parallel implementation is rather difficult, particularly from the viewpoint of portability on various multiprocessor plat-forms. We address this problem by developing PLUM, an automatic and architecture-independent framework for adaptive numerical computations in a message-passing en-vironment. Portability is demonstrated by comparing per-formance on an SP2, an Origin2000, and a T3E, without any code modifications. We also present a general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication pattern, with a goal to providing a global view of system loads across pro-cessors. Experiments on an SP2 and an Origin2000 demon-strate the portability of our approach which achieves superb load balance at the cost of minimal extra overhead. 1