Issue No. 10 - October (1995 vol. 6)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/71.473515
<p><it>Abstract</it>—Deadlock avoidance is a key issue in wormhole networks. A first approach [<ref rid="BIBD10558" type="bib">8</ref>] consists of removing the cyclic dependencies between channels. Many deterministic and adaptive routing algorithms have been proposed based on that approach. Although the absence of cyclic dependencies is a necessary and sufficient condition for deadlock-free deterministic routing, it is only a sufficient condition for deadlock-free adaptive routing. A more powerful approach [<ref rid="BIBD105511" type="bib">11</ref>] only requires the absence of cyclic dependencies on a connected channel subset. The remaining channels can be used in almost any way. In this paper, we show that the previously mentioned approach is also a sufficient condition. Moreover, we propose a necessary and sufficient condition for deadlock-free adaptive routing. This condition is the key for the design of fully adaptive routing algorithms with minimum restrictions. An example shows the application of the new theory.</p>
Adaptive routing, deadlock avoidance, multicomputers, virtual channels, wormhole.
José Duato, "A Necessary and Sufficient Condition for Deadlock-Free Adaptive Routing in Wormhole Networks", IEEE Transactions on Parallel & Distributed Systems, vol. 6, no. , pp. 1055-1067, October 1995, doi:10.1109/71.473515