A Closer Look I (Write)
On a write access fault at Px, the local directory controller determines if block is locally/remotely allocated; if remote finds home
Controller sends request to home node for blk
Home controller looks up directory entry of blk
- Dirty bit OFF, the home has a clean copy
- Home node sends data to Px w/ presence vector
- Home controller clears directory, sets xth bit ON and sets dirty bit ON
- Px controller sends invalidation requests to all nodes listed in the presence vector