Modelling fully‐adaptive routing in hypercubes

Analytical models for wormhole‐routed hypercubes with deterministic routing have been widely reported in the literature. A model for the hypercube with fully‐adaptive routing has recently been proposed in [1]. It uses M/M/1 queues, and computes a different probability of blocking at each intermediate router along the message path. As a result, the number of equations, and thus the computation steps, to evaluate latency increases with the network size. This paper proposes an alternative model that uses M/G/1 queues, and requires a constant number of computation steps irrespective of the network size. It achieves this by computing only once the mean probability of blocking across the entire path, and using it to determine the blocking time at a given router. Simulation experiments reveal that the model yields accurate latency results.

[1]  Kang G. Shin,et al.  Adaptive Deadlock-Free Routing in Multicomputers Using Only One Extra Virtual Channel , 1993, 1993 International Conference on Parallel Processing - ICPP'93.

[2]  Chita R. Das,et al.  Hypercube Communication Delay with Wormhole Routing , 1994, IEEE Trans. Computers.

[3]  Charles L. Seitz,et al.  The cosmic cube , 1985, CACM.

[4]  José Duato,et al.  A New Theory of Deadlock-Free Adaptive Routing in Wormhole Networks , 1993, IEEE Trans. Parallel Distributed Syst..

[5]  William J. Dally Virtual-Channel Flow Control , 1992, IEEE Trans. Parallel Distributed Syst..

[6]  Daniel H. Linder,et al.  An Adaptive and Fault Tolerant Wormhole Routing Strategy for k-Ary n-Cubes , 1994, IEEE Trans. Computers.

[7]  Leonard Kleinrock,et al.  Theory, Volume 1, Queueing Systems , 1975 .

[8]  William J. Dally,et al.  Performance Analysis of k-Ary n-Cube Interconnection Networks , 1987, IEEE Trans. Computers.

[9]  William J. Dally,et al.  Deadlock-Free Message Routing in Multiprocessor Interconnection Networks , 1987, IEEE Transactions on Computers.

[10]  Joydeep Ghosh,et al.  A Comprehensive Analytical Model for Wormhole Routng in Multicomputer Systems , 1994, J. Parallel Distributed Comput..

[11]  S. F. Nugent,et al.  The iPSC/2 direct-connect communications technology , 1988, C3P.

[12]  Xiaola Lin,et al.  The Message Flow Model for Routing in Wormhole-Routed Networks , 1993, 1993 International Conference on Parallel Processing - ICPP'93.