MPI-2 One-Sided Communications on a Giganet SMP Cluster.

We describe and evaluate an implementation of the MPI-2 one-sided communications on a Giganet SMP Cluster. The cluster runs under Linux with our own port of MPICH 1.2.1, a well-known, portable, non-threaded MPI implementation, to the Virtual Interface Provider Library (VIPL). We call this implementation MPI/VIA. The one-sided communications part was adapted from MPI/SX, a full MPI-2 implementation for the NEC SX-5 vector-parallel supercomputer. We evaluate the performance of the one-sided communications by comparing to point-to-point communication. For applications that can be implemented naturally in both the one-sided and the point-to-point model, the MPI/VIA implementation is such that the user is not penalized by choosing one model over the other.