Computer-implemented method, apparatus, and computer program product for stalling DMA operations during memory migration
AssigneeInternational Business Machines Corporation
InventorsCarl Alfred Bender, Patrick Allen Buckland, Steven Mark Thurber, Adalberto Guillermo Yanes
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Abstract
A computer-implemented method, apparatus, and computer program product are disclosed for migrating data from a source physical page to a destination physical page. A migration process is begun to migrate data from the source physical page to the destination physical page which causes a host bridge to enter a first state. The host bridge then suspends processing of direct memory access operations when the host bridge is in the first state. The data is migrated from the source physical page to the destination physical page while the host bridge is in the first state.
Claims17
A computer-implemented method for migrating data from a source physical page to a destination physical page, said computer-implemented method comprising:
- beginning a migration process to migrate data from said source physical page to said destination physical page;
- responsive to a migration bit set within an entry in a translation and control table for said source physical page, setting a host bridge to a first state;
- suspending processing of direct memory access requests by said host bridge when said host bridge is in said first state;
- interrupting said first state to set said host bridge to a second state when a memory mapped input/output load request is received by said host bridge while said host bridge is in said first state;
- and
- processing direct memory access requests and memory mapped input/output requests while said host bridge is in said second state, wherein direct memory access writes for host bridges associated with said source physical page are flushed.
A computer program product for migrating data from a source physical page to a destination physical page, said computer program product comprising:
- a computer usable storage medium having computer usable program code stored thereon, the computer usable program code comprising:
- computer usable program code responsive to a migration bit set within an entry in a translation and control table for said source physical page, for setting a host bridge to a first state;
- computer usable program code for suspending processing of direct memory access requests by said host bridge when said host bridge is in said first state;
- computer usable program code for interrupting said first state to set said host bridge to a second state when a memory mapped input/output load request is received by said host bridge while said host bridge is in said first state;
- and
- computer usable program code for processing direct memory access requests and memory mapped input/output requests while said host bridge is in said second state, wherein direct memory access writes for host bridges associated with said source physical page are flushed.
An apparatus for migrating data from a source physical page to a destination physical page, said apparatus comprising:
- means for beginning a migration process to migrate data from said source physical page to said destination physical page;
- a page migration mechanism responsive to a migration bit set within an entry in a translation and control table for said source physical page, setting a host bridge to a first state;
- said host bridge suspending processing of direct memory access requests by said host bridge when said host bridge is in said first state;
- said page migration mechanism interrupting said first state to set said host bridge to a second state when a memory mapped input/output load request is received by said host bridge while said host bridge is in said first state;
- and
- said host bridge processing direct memory access requests and memory mapped input/output requests while said host bridge is in said second state.
Dependencies are inferred from the claim text.