A computer system with an integrated directory and processor cache.
Directory entries are maintained to filter probe command and response
traffic for certain coherent transactions. Rather than storing directory
entries in a dedicated directory storage, directory entries may be stored
in designated locations of cache memory subsystem, such as an L2 cache,
associated with a processor core. In one particular implementation,
directory entries are stored within the cache memory subsystem to provide
indications of lines (or blocks) that may be cached in modified,
exclusive, or owned coherency states. The absence of a directory entry for
a particular line may imply that the line is cached in either shared or
invalid states.
