A Closer Look I (Read)
Postulate 1 processor per node, 1 level cache, local MSI protocol
On a read access fault at Px, the local directory controller determines if block is locally/remotely allocated, and if remote finds home
Controller sends request to home node for blk
Home controller looks up directory entry of blk
- Dirty bit OFF, controller finds blk in memory, sends reply, sets xth presence bit ON