Mechanism for reducing latency of memory barrier operations on a multiprocessor system
US6088771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1997 |
| Grant date | Jul 11, 2000 |
| Priority date | — |
| Expiry date | Oct 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3834
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A technique reduces the latency of a memory barrier (MB) operation used to impose an inter-reference order between sets of memory reference operations issued by a processor to a multiprocessor system having a shared memory. The technique comprises issuing the MB operation immediately after issuing a first set of memory reference operations (i.e., the pre-MB operations) without waiting for responses to those pre-MB operations. Issuance of the MB operation to the system results in serialization of that operation and generation of a MB Acknowledgment (MB-Ack) command. The MB-Ack is loaded into a probe queue of the issuing processor and, according to the invention, functions to pull-in all previously ordered invalidate and probe commands in that queue. By ensuring that the probes and invalidates are ordered before the MB-Ack is received at the issuing processor, the inventive technique provides the appearance that all pre-MB references have completed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.