Collective Communications on a Reconfigurable Optical Interconnect1
Ahmad Afsahi and Nikitas J. Dimopoulos
Department of Electrical and Computer Engineering
University of Victoria
P.O. Box 3055, Victoria, B.C., Canada, V8W 3P6
Abstract. Free-space optical interconnection is used to fashion a reconfigurable net-
work. Latency hiding techniques are used to enhance its performance. For this net-
work, we present and analyze broadcasting/multi-broadcasting algorithms that utilizes
latency hiding and reconfiguration. A combined total exchange algorithm has been
proposed based on a combination of the direct, and standard exchange algorithms.
Also, known algorithms for other collective communication primitives have been
adapted to our network.
Keywords: Massively parallel computers, collective communications, reconfigurable
free-space optical interconnects.
Message-passing multicomputers are composed of a large number of processor/mem-
ory modules that communicate with each other by exchanging messages through
their point-to-point interconnection networks. As the communication overhead is one