Method and apparatus for reducing cache thrashing

Abstract

A method and apparatus are disclosed for adaptively decreasing cache trashing in a cache memory device. Cache performance is improved by automatically detecting thrashing of a set and then providing one or more augmentation frames as additional cache space. In one embodiment, the augmentation frames are obtained by mapping the blocks that map to a thrashed set to one or more additional, less utilized sets. The disclosed cache thrashing reduction system initially identifies a set that is likely to be experiencing thrashing, referred to herein as a thrashed set. Once thrashing is detected, the cache thrashing reduction system selects one or more additional sets to augment a thrashed set, referred to herein as the augmentation sets. In this manner, blocks of main memory that are mapped to a thrashed set are now mapped to an expanded group of sets (the thrashed set and the augmentation sets). Finally, when the augmentation sets are no longer likely to be needed to decrease thrashing, the augmentation set(s) are disassociated from the thrashed set(s).