Classifying the cache misses:The 3 C’s
Compulsory misses (cold start)
- The first time you touch a block. Reduced (for a given cache capacity and associativity) by having large blocks
Capacity misses
- The working set is too big for the ideal cache of same capacity and block size (i.e., fully associative with optimal replacement algorithm). Only remedy: bigger cache!
Conflict misses (interference)
- Mapping of two blocks to the same location. Increasing associativity decreases this type of misses.
There is a fourth C: coherence misses (cf. multiprocessors)