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 performing the steps 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 a packet header for a completion notification packet;
• transferring, by the origin DMA engine to the target compute node, the application message in dependence upon the data descriptor;
• sending, by the origin DMA engine, the completion notification packet to a local reception FIFO buffer using a local memory FIFO transfer operation;
• and
• notifying, by the origin DMA engine, the application that transfer of the application message is complete in response to receiving the completion notification packet in the local reception FIFO buffer.

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 performing the steps 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 a packet header for a completion notification packet;
• transferring, by the origin DMA engine to the target compute node, the application message in dependence upon the data descriptor;
• sending, by the origin DMA engine, the completion notification packet to a local reception FIFO buffer using a local memory FIFO transfer operation;
• and
• notifying, by the origin DMA engine, the application that transfer of the application message is complete in response to receiving the completion notification packet in the local reception FIFO buffer.