Two-stage request protocol for accessing remote memory data in a NUMA data processing system
US6615322B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2001 |
| Grant date | Sep 2, 2003 |
| Priority date | — |
| Expiry date | Nov 23, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/1056
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A non-uniform memory access (NUMA) computer system includes a remote node coupled by a node interconnect to a home node having a home system memory. The remote node includes a local interconnect, a processing unit and at least one cache coupled to the local interconnect, and a node controller coupled between the local interconnect and the node interconnect. The processing unit first issues, on the local interconnect, a read-type request targeting data resident in the home system memory with a flag in the read-type request set to a first state to indicate only local servicing of the read-type request. In response to inability to service the read-type request locally in the remote node, the processing unit reissues the read-type request with the flag set to a second state to instruct the node controller to transmit the read-type request to the home node. The node controller, which includes a plurality of queues, preferably does not queue the read-type request until receipt of the reissued read-type request with the flag set to the second state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.