Redistribution of Block-Cyclic Data Distributions Using MPI

D. W. Walker
Mathematical Sciences Section
Oak Ridge National Laboratory
P. O. Box 2008
Oak Ridge, TN 37831-6367
U. S. A.
S. W. Otto
Department of Computer Science and Engineering
Oregon Graduate Institute
Beaverton, OR 97291-1000
U. S. A.

Abstract

Arrays that are distributed in a block cyclic fashion are important for many applications in the computational sciences since they often lead to parallel algorithms with good load balancing properties. We consider the problem of redistributing such an array to a new block size. This operation is directly expressible in High Performance Fortran (HPF) and will arise in applications written in this language. Efficient message passing algorithms are given for the redistribution operation, expressed in the standardized message passing interface, MPI. The algorithms are analyzed and performance results from the IBM SP-1 and Intel Paragon are given and discussed. The results show that redistribution can be done in time comparable to other collective communication operations, such as broadcast and mpi_alltoall.

D. W. Walker and S. W. Otto, Redistribution of Block-Cyclic Data Distributions Using MPI, Concurrency: Practice and Experience, Vol. 8, No. 9, pages 707-728, November 1996.