Exclusivity Through DLAT Only-Copy Indication
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Integral to store-completion, existing high-end (nonbroadcast) coherency schemes employ methods of obtaining exclusive ownership of lines. Within this context, the use of the term "exclusive ownership" implicitly includes (what amounts to) locking the line via formal hardware protocol. Such protocols guarantee adherence to a given storage architecture, but in-and-of themselves, the protocols superfluously (and with substantial overhead) ensure such adherence when indication of an "only copy" is locally available. Specifically, the local DLAT can indicate those mappings that are only held by the local processor, thus alleviating the need for the director to engage a formal protocol for ensuring store-completion to lines within a given page.