What is MESI protocol?

A coherence protocol that tracks each cache line in one of four states: Modified, Exclusive, Shared or Invalid. On a write it invalidates other cores' copies.

Field: Multicore & Synchronization

Questions that mention MESI protocol (2)

  1. In the MESI protocol, what does it mean when a cache line is in the Modified (M) state?
  2. In the MESI protocol, what happens when a core writes to a line it holds in the Exclusive (E) state?

Related terms

Cache line ABA problem Acquire-release semantics Atomic instruction Barrier synchronization Bus snooping Compare-and-swap Condition variable Critical section Data race

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