R. Cypher and L. Gravano, "Requirements for deadlock-free, adaptive packet routing," in Proc. 11th ACM Symp. Principles Distributed Computing, 1992.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....conditions to verify that an adaptive algorithm is deadlock free, even when there are cyclic dependencies between channels. We also proposed two design methodologies. The first one supplies fully adaptive routing algorithms and it is very similar to the one proposed in [33, 34] Cypher and Gravano [6] proposed a necessary condition for deadlock free adaptive routing in packet switched networks with central queues. They showed that an adaptive deadlock free packet routing algorithm can always be restricted, obtaining an oblivious deadlock free routing algorithm. This is not a sufficient ....

....by routing packets starting from an empty network. This situation usually arises when two or more packets require the use of the same resource at the same time to reach the configuration. A configuration that can be reached by routing packets starting from an empty network is reachable or routable [6]. If all the configurations are reachable then a static analysis of the network is enough. Otherwise, the dynamic evolution of the network should be considered. This dynamic analysis is not required to prove that a routing function is deadlock free. Reachability only affects necessary conditions ....

[Article contains additional citation context not shown here]

R. Cypher and L. Gravano, "Requirements for deadlock-free, adaptive packet routing," in Proc. 11th ACM Symp. Principles Distributed Computing, 1992.

....turn model is also based on Dally s theorem, requiring the absence of cycles in the channel dependency graph. This approach is too restrictive, limiting the number of alternative paths that can be used. A different approach consists of allowing the existence of cyclic dependencies between channels [2, 6, 11, 29]. In this case, it is possible to provide fully adaptive routing with a modest number of virtual channels or buffers. For instance, the channels routing algorithm for the torus topology [2] prevents deadlock by dynamically disallowing paths based on occupancy of buffers in neighboring nodes. ....

R. Cypher and L. Gravano, "Requirements for deadlock-free adaptive packet routing," in Proc. 11th ACM Symp. Principles Distributed Computing, 1992.

....routing, wormhole routing A preliminary version of this paper appeared in the Proceedings of the Seventh IEEE Symposium on Parallel and Distributed Processing, 1995. 1 Introduction This paper studies deadlock free buffer reservation algorithms, where a buffer reservation algorithm [6] is a routing algorithm that specifies to which buffers a message may move based solely on the buffer currently holding the message and the message s source and destination nodes. A message is allowed to move from its current buffer to any other buffer at any time, provided that the other buffer ....

....virtual cut through, or wormhole routing algorithm that is oblivious and deadlock free, there exists a total ordering of the buffers such that every message is always allowed to move to a higher ordered buffer or to be delivered. The following theorem was proven by Cypher and Gravano [6]. Theorem 2.3 Given any store and forward or virtual cut through routing algorithm that is adaptive and deadlock free, there exists a deadlock free oblivious algorithm that allows a subset of the moves allowed by the adaptive algorithm. 3 Lower Bounds It follows from Theorem 2.2 that given any ....

R. Cypher and L. Gravano, "Requirements for Deadlock-Free, Adaptive Packet Routing ", SIAM J. on Computing, vol. 23, no. 6, pp. 1266--1274, 1994.

....node, regardless of the size and dimension of the torus. Furthermore, the requirement of three queues per node is optimal, as it has been proven that it is impossible to create a minimal deadlock free routing algorithm for tori (whether or not it is adaptive) which uses only two queues per node [4]. We will also present a minimal fully adaptive routing algorithm for torus networks of arbitrary size and dimension which is free of deadlock, livelock, and starvation and yet requires only that each node have two input buffers per edge. All previously known algorithms with the same properties ....

....become empty again, so the algorithm is free of starvation for incoming packets. 2 Thus routing Algorithm 1 is minimal fully adaptive and free of deadlock, livelock, and starvation, and yet it requires only three queues per node. The following theorem, which was proven by Cypher and Gravano [4], shows that the requirement of three queues per node is optimal, in the sense that no minimal algorithm which requires only two queues per node is free of deadlock. Theorem 3.5 Any torus routing algorithm of the type defined in Section 2.2 which is minimal and free of deadlock requires that some ....

[Article contains additional citation context not shown here]

Robert Cypher and Luis Gravano. Requirements for deadlock-free adaptive packet routing. In Proc. 11th Annual ACM Symposium on Principles of Distributed Computing, pages 25--33, 1992.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC