Snoopy Protocols: Performance and Implementation
Admin
Review: 4-State (MESI) Invalidation Protocol
Review: 4-State Write-back Update Protocol
Tradeoffs in Protocol Design
Computing Bandwidth
MESI State Transitions and Bandwidth
Bandwidth of MSI vs. MESI
MSI BusUpgrd vs. BusRdX
Cache Block Size
Invalidate vs. Update
Pattern 1
Pattern 2
Implementing Coherence Protocols
What is Correctness?
A Simple Design
Cache Controller
Presenting Snoop Results
How to Present Snoop Results
Non-Atomic State Transitions
Problems from Non-Atomic Transitions
Adding Transient States
Write-Backs and Starvation
Multi-Level Caches
Multi-Level Caches (Continued)
Review
Next Time
Email: alvy@cs.duke.edu
Home Page: http://www.cs.duke.edu/~alvy