Page crossing prefetches

摘要

Prefetching is permitted to cross from one physical memory page to another. More specifically, if a stream of access requests contains virtual addresses that map to more than one physical memory page, then prefetching can continue from a first physical memory page to a second physical memory page. The prefetching advantageously continues to the second physical memory page based on the confidence level and prefetch distance established while the first physical memory page was the target of the access requests.

主权项

1. A system comprising:
a plurality of caches; and a prefetcher configured to prefetch cache lines from a first physical memory page into a cache of the plurality of caches, wherein the cache lines prefetched into the cache are selected using a prediction determined from a pattern of accesses across the first physical memory page associated with the cache and also using a first prefetch distance that is determined based on the pattern of the accesses, wherein a value for the first prefetch distance corresponds to a value for a first confidence level that is also determined based on the pattern of the accesses, wherein cache lines in a second physical memory page are selected for prefetching using the pattern and a value for a second prefetch distance that is based on the value of the first prefetch distance and that corresponds to a value for a second confidence level that is based on the value of the first confidence level.