Shadow commands to optimize sequencing of requests in a switch-based multi-processor system
US6279084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1997 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Oct 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0826
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention pertains to serializing local and remote references to a portion of a shared memory to optimize sequencing of requests in a switch-based, multi-processor system in which the local and remote references can occur concurrently. Usually, local accesses are typically much faster than remote accesses. Thus, in the interest of performance, both local and remote accesses are permitted to occur concurrently in the multiprocessing system. However, in one instance a local access can cause deadlock problems for a remote access. In addition, problems associated with coherency of the shared memory can also arise. Thus, in order to prevent deadlock problems and to maintain coherency of a shared memory, if a local reference to an address of memory has been forwarded to a switch, in this instance a hierarchical switch, then all subsequent references to that address of memory are forwarded to the hierarchical switch. The hierarchical switch has ordering properties that maintain the received order of inputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.