Method and system for avoiding data loss due to cancelled transactions within a non-uniform memory access system
US6192452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1999 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Feb 26, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0813
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for avoiding data loss due to cancelled transactions within a non-uniform memory access (NUMA) data processing system is disclosed. A NUMA data processing system includes a node interconnect to which at least a first node and a second node are coupled. The first and the second nodes each includes a local interconnect, a system memory coupled to the local interconnect, and a node controller interposed between the local interconnect and a node interconnect. The node controller detects certain situations which, due to the nature of a NUMA data processing system, can lead to data loss. These situations share the common feature that a node controller ends up with the only copy of a modified cache line and the original transaction that requested the modified cache line may not be issued again with the same tag or may not be issued again at all. The node controller corrects these situations by issuing its own write transaction to the system memory for that modified cache line using its own tag, and then providing the data the modified cache line is holding. This ensures that the modified data will be written to the system memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.