A Localised Algorithm for Optimising Unstructured Mesh Partitions

C. Walshaw, M. Cross and M. G. Everett


A new method is described for optimising graph partitions which arise in mapping unstructured mesh calculations to parallel computers. The method employs a combination of iterative techniques to both evenly balance the workload and minimise the number and volume of interprocessor communications. When combined with a fast direct partitioning technique (such as the Greedy algorithm) to give an initial partition, the resulting two-stage process proves itself to be both a powerful and flexible solution to the static graph-partitioning problem. A clustering technique can also be employed to speed up the whole process. Experiments, on graphs with up to a million nodes, indicate that the resulting code is up to an order of magnitude faster than existing state-of-the-art techniques such as Multilevel Recursive Spectral Bisection, whilst providing partitions of equivalent quality.

Key words. graph-partitioning, unstructured meshes, load-balancing, parallel scientific computation.

Fri Aug 13 13:40:38 BST 2004