Parallel Computer Architecture

8.4 Design Challenges for Directory Protocols 579

a small cache, dirty data may be replaced and written back, so a sharing miss by

another processor may be satisfied at the home node rather than at the previously

dirty node. For applications like Ocean that allow data to be placed easily in the

memory of the node to which they are assigned (i.e., to be appropriately distributed

for locality), it is often the case that only that node writes the data, so even if the

data is found dirty, it is found so in a cache at the home node

itself.

The extent to

which this is true depends on the data access patterns of the application, the granu-

larity o ...