Dead Block Replacement and Bypass with a Sampling Predictor
Résumé
We present a cache replacement and bypass policy driven by dead block prediction. A block is considered dead is it will be replaced before it will be used again. If dead blocks can be identified, then they can be replaced early. If a block is predicted to be “dead on arrival,” i.e., it will not be accessed again after it is placed in the cache, then it can bypass the cache. The predictor is based on one simple observation: if a block becomes dead after being touched by a particular instruction, then other blocks touched by that instruction are also likely to become dead. Ideally, we would track the tendency of blocks to become dead for every instruction accessing the cache. However, to fit within a realistic hardware budget, we sample only a few sets from the cache. This paper describes our sampling dead block predictor and the techniques used to make it fit within the allow hardware budget for the cache replacement contest.
Domaines
Architectures Matérielles [cs.AR]Origine | Fichiers produits par l'(les) auteur(s) |
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