A Comment on “A Necessary and Sufficient Condition for Deadlock-Free Adaptive Routing in Wormhole Networks”
Freek Verbeek, Julien Schmaltz · IEEE Transactions on Parallel and Distributed Systems · 2011
The purpose of this comment is to show that Duato's condition for deadlock freedom is only sufficient and not necessary. We propose a fix to keep the condition necessary. The issue is subtle but essential: in a wormhole network worms necessarily do not intersect.