I got a question, what is outstanding misses, and I got an answer from slides 4 years ago: the concept of outstanding misses is related to a "non-blocking" cache. If a processor asks the L1 cache for data and there is a cache miss, instead of waiting for the request to be serviced by the L2 cache, the L1 cache has mechanisms to continue working on other requests. The first request that had to go to the L2 cache is the "outstanding miss." The L1 cache in this diagram could have up to 10 requests for such misses out at a time before it has to block.
I got a question, what is outstanding misses, and I got an answer from slides 4 years ago: the concept of outstanding misses is related to a "non-blocking" cache. If a processor asks the L1 cache for data and there is a cache miss, instead of waiting for the request to be serviced by the L2 cache, the L1 cache has mechanisms to continue working on other requests. The first request that had to go to the L2 cache is the "outstanding miss." The L1 cache in this diagram could have up to 10 requests for such misses out at a time before it has to block.