Accuracy and Coverage
#Prefetch_all: Number of prefetches
#Prefetch_hit: Number of prefetches that result in a cache hit
#Misses: Number of cache misses
Notes:
How effective a prefetching technique is, is measure by its coverage. The prefetch coverage is the percentage of cache misses that were partially or completely removed.
Because of its speculative nature, prefetching can bring data to the cache that is not needed by the processor or that arrives too early or too late to reduce the cache miss stall time. A useful prefetch brings data to the L1 cache that will be referenced. The percentage of useful prefetches is called the prefetch accuracy.
While all prefetch techniques try to achieve a perfect coverage, an important goal is to do so accurately to avoid additional overhead on the memory system.