On the Reduction of Deadlock Frequency by Limiting Message Injection in Wormhole Networks

Recently, deadlock recovery strategies began to gain acceptance in networks using wormhole switching. In particular, progressive deadlock recovery techniques are very attractive because they allocate a few dedicated resources to quickly deliver deadlocked packets, instead of killing them. Deadlock recovery is based on the assumption that deadlocks are really rare. Otherwise, recovery techniques are not eecient. In this paper, we propose the use of a message injection limitation mechanism that reduces the probability of deadlock to negligible values, even when fully adaptive routing is used. The main new feature is that it can be used with diierent message destination distributions. The proposed mechanism can be combined with any deadlock detection mechanism. In particular, we use the deadlock detection mechanism proposed in 21]. In addition, the proposed injection limitation mechanism considerably reduces performance degradation when the network reaches the saturation point.