PROMOTION OF A CACHE LINE SHARER TO CACHE LINE OWNER

摘要

A system and method for performing coherent cache snoops whereby a single or limited number of sharing coherent agents are snooped for a data access. A directory may store information identifying which coherent agents have a shared copy of a cache line. If more than one might be in a shared state, one is promoted to an owner state within the directory. Accesses to the shared cache line are responded to by a snoop to just one, or a number less than all, of the caching agents sharing the cache line.