Methods to maintain triangle ordering of coherence messages
US7343454B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 16, 2004 |
| Grant date | Mar 11, 2008 |
| Priority date | — |
| Expiry date | Nov 4, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0813
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
We present a triangle ordering mechanism that maintains triangle ordering of coherence messages in SMP systems. If cache A sends a multicast message to caches B and C, and if cache B sends a message to cache C after receiving and processing the multicast message from cache A, the triangle ordering mechanism ensures that cache C processes the multicast message from cache A before processing the message from cache B. The triangle ordering mechanism enables efficient snoopy cache coherence in SMP systems in which caches communicate with each other via message-passing networks. A modified version of the triangle ordering mechanism categorizes coherence messages into non-overlapping sequencing classes, and ensures triangle ordering for coherence messages in the same sequencing class. The modified triangle ordering mechanism can significantly reduce potential performance degradation due to false waiting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.