Apple Inc.
Victim allocations in shared system cache

Abstract:

A system and method for efficiently handling data selected for eviction in a computing system. In various embodiments, a computing system includes one or more processors, a system memory, and a victim cache. The cache controller of a particular cache in a cache memory subsystem includes an allocator for determining whether to allocate data evicted from the particular cache into the victim cache. The data fetched into the first cache includes data fetched to service miss requests, which includes demand requests and prefetch requests. To determine whether to allocate, the allocator determines whether a usefulness of data fetched into the particular cache exceeds a threshold. If so, the evicted data is stored in the victim cache. If not, the evicted data bypasses the victim cache. Data determined to be accessed by a processor is deemed to be of a higher usefulness.