Memory consistency

Consistency model

Sequential consistency

What is program order?

OOO and SC

SC example

Implementing SC

Write atomicity

Summary of SC

Back to shared bus

Snoopy protocols

Stores

Invalidation vs. update

Which one is better?

MSI protocol

State transition

MSI protocol

M to S, or M to I?

MSI example

MESI protocol

State transition

MESI protocol

MESI example