An efficient, fully adaptive deadlock recovery scheme

Abstract

This paper presents a simple, efficient and cost effective routing strategy that considers deadlock recovery as opposed to prevention. Performance is optimized in the absence of deadlocks by allowing maximum flexibility in routing. Disha supports true fully adaptive routing where all virtual channels at each node are available to packets without regard for deadlocks. Deadlock cycles, upon forming, are efficiently broken by progressively routing one of the blocked packets through a deadlock-free lane. This lane is implemented using a central "floating" deadlock buffer resource in routers which is accessible to all neighboring routers along the path. Simulations show that the Disha scheme results in superior performance and is extremely simple, ensuring quick recovery from deadlocks and enabling the design of fast routers.