Parallel Computer Architecture

760 CHAPTER 10 Interconnection Network Design

down to a rate that can move through the bottleneck. Increasing the amount of

buffering within the network allows contention to persist longer without causing

back pressure at the source, but it also increases the potential queuing delays within

the network when contention does occur.

One of the concerns that arises in networks with message blocking is that the

backup can impact traffic that is not headed for the highly contended output. Sup-

pose that the network traffic favors one of the destinations, say, because it holds an

important global variable that is widely used. This is often called a ...