Serialized access to an I/O adapter through atomic operation
US8346975B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2009 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | Oct 17, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2213/0024
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a computer implemented method, computer program product, and apparatus to enqueue one or more packets in a device driver for an I/O adapter. A device driver receives, by a processor executing the device driver, a reference to a list of transmit packets. The device driver may then atomically fetch and set a transmit active flag, wherein atomically setting comprises determining a former status of the transmit active flag. Responsive to a determination that a former status of the transmit active flag is different than a current status of the transmit active flag, the device driver atomically removes, by a processor executing the device driver, any packets referenced by a host machine transmit queue reference. The device driver pre-pends transmit packets referenced by the host machine transmit queue reference to the list of transmit packets to form an augmented list of transmit packets. The device driver builds a work request based on the augmented list of transmit packets. The device driver notifies the I/O adapter of the work request. The device driver atomically resets the transmit active flag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.