Advanced Computer Architecture Chapter 7.25
Berkeley
cache coherence protocol:
state transition diagram
state transition diagram
1. INVALID
2. VALID: clean, potentially shared,
unowned
3. SHARED-DIRTY: modified, possibly shared, owned
4. DIRTY: modified, only copy, owned
The
Berkeley protocol
is representative
of how
typical bus-based
SMPs work
Q: What has to happen on a “Bus read miss”?