System for evicting or clearing data from a cache based on the eviction class tag of the data stored in the cache.

摘要

Disclosed is a system for evicting, clearing, deleting or removing data from a level 2 memory cache, based on the eviction class of the data. The system has a tag store unit that stores a different entry for each of the cache lines associated with the cache. Each entry includes a tag indicating the eviction class and the state ie clean/unclean and unpinned/pinned, associated with the data stored in the cache line. The eviction class indicates the likelihood that data stored in the cache will be reused by one of the clients. When the tag look-up unit receives a command from a client including an address, the look-up unit identifies the cache lines that might store data based on the received address. The look-up unit then determines if there is a cache miss, and if there is it causes data residing in cache lines to be evicted based on eviction class of the data. The eviction classes may be evict-first, evict-normal and evict-last, with the look-up unit able to re-class data when required.