Advanced Computer Architecture Chapter 7: shared memory and cache consistency

Advanced Computer Architecture, Imperial College 2001

S3MP - Writes

•If the line is exclusive (i.e. dirty bit is set) no message is required

•Else send a write-request to the home

–Home sends an invalidation message down the chain

–Each copy is invalidated (other than that of the requester)

–Final node in chain acknowledges the requester and the home

•Chain is locked for the duration of the invalidation