Direct Memory Access Transfer Completion Notification

An origin compute node capable of Direct Memory Access (‘DMA’) transfer completion notification, the compute node comprising a DMA controller, an origin DMA engine installed upon the DMA controller, a computer processor, and computer memory operatively coupled to the computer processor, the DMA controller, and the origin DMA engine, the computer memory having disposed within it computer program instructions capable of:

• inserting, by an origin DMA engine on an origin compute node in an injection first-in-first-out (‘FIFO’) buffer, a data descriptor for an application message to be transferred to a target compute node on behalf of an application on the origin compute node;
• inserting, by the origin DMA engine, a completion notification descriptor in the injection FIFO buffer after the data descriptor for the application message, the completion notification descriptor specifying an address of a completion notification field in application storage for the application;
• transferring, by the origin DMA engine to the target compute node, the application message in dependence upon the data descriptor;
• and
• notifying, by the origin DMA engine, the application that the transfer of the application message is complete, including performing a local direct put operation to store predesignated notification data at the address of the completion notification field.

A computer program product for Direct Memory Access (‘DMA’) transfer completion notification, the computer program product disposed upon a computer readable medium, the computer program product comprising computer program instructions capable of:

• inserting, by an origin DMA engine on an origin compute node in an injection first-in-first-out (‘FIFO’) buffer, a data descriptor for an application message to be transferred to a target compute node on behalf of an application on the origin compute node;
• inserting, by the origin DMA engine, a completion notification descriptor in the injection FIFO buffer after the data descriptor for the application message, the completion notification descriptor specifying an address of a completion notification field in application storage for the application;
• transferring, by the origin DMA engine to the target compute node, the application message in dependence upon the data descriptor;
• and
• notifying, by the origin DMA engine, the application that the transfer of the application message is complete, including performing a local direct put operation to store predesignated notification data at the address of the completion notification field.