A load-balanced routing method for large-scale mesh multiprocessors

Abstract

Research on message routing in large-scale mesh multiprocessors usually focuses on routing in light traffic. Studies employ simple routing methods that are not load-balanced but do not need route initiation before message transmission. In non-light and/or non-uniform input traffic situations, maximum bandwidth utilization and average latency of such routing methods can be poor due to congestion caused by unbalanced load in global mesh regions. Existing load-balanced routing methods applied in mobile ad hoc mesh networks require route initiation before message transmission, which is not acceptable in mesh multiprocessors. In this research, we designed a load-balanced hierarchical mesh-routing method without route initiation. We organize a large-scale mesh into a virtually structured hierarchical mesh structure. Global mesh routing can thus be transformed into a number of load-balanced routing subtasks at levels of hierarchical submesh regions. In such a structure, we designed periodical hierarchical traffic state polling and distribution with very low overhead. We developed two congestion-avoidance routing methods for load-balanced routing at levels of submesh regions with polled traffic states. Experimental results show that maximum bandwidth utilization and average latency in non-light and/or non-uniform input traffic situations can be improved significantly in comparison with ordinary mesh multiprocessor routing methods.