Parallel Computer Architecture

594 CHAPTER 8 Directory-Based Cache Coherence

Deadlock

In Chapter 7, we discussed an important source of potential deadlock in request-

response protocols such as those of a shared address space: the filling up of a finite

input buffer. Three solutions were proposed for buffer deadlock:

1.

Provide enough buffer space, either by buffering requests at the requestors

using distributed linked lists or by providing enough input buffer space (in

hardware or main memory) for the maximum number of possible incoming

transactions.

2.

UseNACKs.

3.

Provide separate request and response networks, whether physically separate

or multiplexed with separate buffers ...