Atomic memory migration apparatus and method
AssigneeInternational Business Machines Corporation
InventorRandal Craig Swanberg
Life of this patent
Estimating the term…
Abstract
An atomic memory migration apparatus and method are provided. With the apparatus and method, all active DMA mappings to a given physical page of memory are identified and future mappings/unmappings to the physical page are serialized with migrations of current mappings. The identified DMA mappings are then disabled at the bus level and the physical page is migrated to a new memory page. All existing DMA mappings are also migrated to the new page. After migration is completed, the DMA mappings, which have now been migrated to the new page, are reenabled at the bus level.
Claims37
A method of migrating a memory page, comprising:
- sending a state notification from an operating system kernel to a Direct Memory Access (DMA) mapper;
- modifying a page migration state of a state machine associated with the DMA mapper based on the state notification;
- and
- performing one or more page migration operations based on the modification of the state of the state machine.
A computer program product in a computer readable medium for migrating a memory page, comprising:
- first instructions for sending a state notification from an operating system kernel to a Direct Memory Access (DMA) mapper;
- second instructions for modifying a page migration state of a state machine associated with the DMA mapper based on the state notification;
- and
- third instructions for performing one or more page migration operations based on the modification of the state of the state machine.
An apparatus for migrating a memory page, comprising:
- means for sending a state notification from an operating system kernel to a Direct Memory Access (DMA) mapper;
- means for modifying a page migration state of a state machine associated with the DMA mapper based on the state notification;
- and
- means for performing one or more page migration operations based on the modification of the state of the state machine.
Dependencies are inferred from the claim text.