Once upon a time, my computer architecture professor mentioned that using a random eviction policy for caches really isn't so bad. That random eviction isn't bad can be surprising -- if your cache fills up and you have to get rid of something, choosing the least recently used (LRU) is an obvious choice, since you're more likely to use something if you've used it recently. If you have a tight loop, LRU is going to be perfect as long as the loop fits in cache, but it's going to cause a miss every ...