Non-speculative distributed conflict resolution for a cache coherency protocol
US6954829B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2002 |
| Grant date | Oct 11, 2005 |
| Priority date | — |
| Expiry date | Mar 26, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0813
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A conflict resolution technique provides consistency such that all conflicts can be detected by at least one of the conflicting requestors if each node monitors all requests after that node has made its own request. If a line is in the Exclusive, Modified or Forward state, conflicts are resolved at the node holding the unique copy. The winner of the conflict resolution, and possibly the losers, report the conflict to the home node, which pairs conflict reports and issues forwarding instructions to assure that all requesting nodes eventually receive the requested data. If a requested cache line is either uncached or present only in the Shared state, the home node provides a copy of the cache node and resolves conflicts. In one embodiment, a blackout period after all responses until an acknowledgement message has been received allows all conflicting nodes to be aware of conflicts in which they are involved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.