Turn Grouping for Multicast in Wormhole-Routed Mesh Networks Supporting the Turn Model

Abstract

Multicast is an important collective communication in scalable parallel computers. One efficient scheme to perform multicast is multidestination messagingl8r. In multidestination messaging, destination nodes of a multicast are partitioned into disjoint groups. Nodes in each group are reached with a multidestination message that conforms to the base routing algorithm of the system. A systematic way of partitioning the nodes is critical to the efficiency of multidestination messaging. In this paper we propose a node grouping method, called turn grouping, for partitioning the destination nodes in a multicast. Turn grouping is general in the sense that it supports any base routing algorithm derivable from the turn model l5r. Given such a base routing algorithm and the corresponding prohibited turns, turn grouping can systematically produce a proper schedule for multicasting the message. We evaluated the performance of turn grouping using three typical turn model-based routing algorithms. The simulation results show that our approach performs better than the Umesh l12r and the Hamiltonian-path l8r algorithms.