The Two-Level-Turn-Model Fault-Tolerant Routing Scheme in Tori with Convex and Concave Faults

A kind of routing scheme with the ability to tolerate the faults is necessary in the massively parallel multiprocessors. In this paper, we have proposed a kind of fault-tolerant routing scheme in the tori networks. The new routing scheme is called the two-level-turn-model routing scheme, which is based on our investigation of the fault-tolerant properties of the turn-model. Through employing two specific kinds of turn model, our routing scheme could tolerate the convex faults and the concave faults both with a few limitations to their shape. At most five virtual channels would be used to avoid the deadlock occurrence in the tori, no matter whether the fault regions are connected and no matter where the faults locate. Actually, if the fault regions encompass no physical boundary nodes in the tori, totally four virtual channels, each pair for each turn model, would be sufficient to preclude the occurrence of the deadlock. At last, the simulation shows the effectiveness of our scheme.