Software routing support for task migration in hypercube multiprocessor systems

The problem of efficient task migration in hypercube multiprocessors is addressed. Task migration is useful for subcube reallocation, dynamic task sizing, load balancing, and support of fault tolerance. Efficient routing algorithms for large messages can increase the benefits obtained from migration. While pipelined communication techniques allow a maximum reduction in communication time, hardware costs for these solutions may be extreme. Current technology limits the extent to which communication links can be used simultaneously, and therefore the architectural support of pipelined communications in hypercubes. The proposed centralized algorithm applies an optimization heuristic in an idealized, static, nonpipelined setting and further uses retrograde motion to maximize the utilization of available bandwidth. The algorithm is applied to a dynamic system, and simulation studies evaluate the actual performance. The results provide a basis for extension and enhancement of the existing algorithm to a distributed routing algorithm