The last-level cache, or LLC, adds data storage below the private caches. Its inclusion policy decides where a line goes on a miss, on a private eviction and on an LLC eviction, and whether an LLC tag lookup can double as the directory.
Lesson | After it you can... |
|---|---|
Say where a line goes on a miss, a private eviction and an LLC eviction under each policy. | |
Explain why an inclusive LLC eviction invalidates private copies, and what an inclusion victim is. | |
Say when an LLC tag miss proves no private copy exists. | |
Compare unique capacity, snoop filtering and bandwidth across the three policies. |
Read after Part 7 directory capacity. Private MESI permissions follow the course model unchanged.
No. A private M holder can hold newer data than the LLC. In the inclusive case the LLC tag carries presence bits that point H at that holder.