Approach for Deadlock Handling in Torus Network

Wormhole routing is a popular switching technique being used in current generation parallel systems. Wormhole Routing is successful to deadlock due to its pipeline operation in the networks. In this book two deadlock free Wormhole Routing algorithms are given for Torus networks. First a simple and efficient minimal adaptive wormhole routing algorithm is presented that recovers from potential deadlocks. This algorithm removes those packets from the network that have stalled for more than a given timeout in a router. Second a fault-tolerant and non-adaptive routing algorithm is proposed for wormhole routed torus networks. This can tolerate any number of non-overlapping rectangular faulty blocks with simple logic and requires only three virtual channels. The algorithm is proved to provide deadlock-livelock free routing with non-overlapping f-rings. The use of such a limited number of virtual channels will significantly reduce the implementation cost of the algorithm in router hardware.