Turn-based Deadlock Detection for Wormhole Routed Networks

Deadlock detection and recovery-based routing protocols in wormhole networks have gained attraction because they do not restrict routing adaptability unlike deadlock avoidance-based protocols. Network performance largely relies on the accuracy of deadlock detection. The lower the number of packets presumed as deadlocked by a protocol, the better the network performs, since the network rarely enters into deadlock state in reality and those packets presumed as deadlocked are usually killed or recovered according to a recovery procedure, causing extra overhead to the network. This paper proposes a deadlock detection protocol based on the turn model. It declares only one packet per simple cycle of blocked packets as deadlocked in most cases, thus considerably reducing the number of false deadlock detections over previous protocols. This results in less number of unnecessary recoveries to resolve deadlock. This achievement is made with lower hardware complexity than a most sophisticated previous protocol. The simulation study shows that our protocol outperforms previous protocols in the number of deadlock detections.