Mapping strategies in message-based multiprocessor systems

Machines with distributed memory have the mapping problem-assigning processes to processors. In this paper we define the mapping problem as an optimization problem and discuss the question, how far is an optimum solution from an average or random solution. The term robustness is introduced and explained in detail with two examples, the SUPRENUM and the hypercube architecture. For the SUPRENUM architecture we show that a simple mapping strategy (optimal clustering of the processes) gives almost as good results as the optimal mapping. Optimal mapping is more important for the hypercube architecture. For nonhomogeneous networks adaptive routing seems promising.