Signaling completion of a message transfer from an origin compute node to a target compute node

An origin compute node capable of signaling completion of a message transfer from an origin compute node to a target compute node, the compute node comprising a direct memory access (‘DMA’) controller, an origin DMA engine installed upon the DMA controller, a computer processor, 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:

• sending, by an origin DMA engine on an origin compute node to a target DMA engine on a target compute node, a request to send message on behalf of an application on the origin compute node, the request to send message specifying an application message for transfer to the target compute node from the origin compute node;
• receiving, by the origin DMA engine from the target DMA engine, a remote get message containing a data descriptor for the application message and a completion notification descriptor, the data descriptor specifying a data transfer operation for transferring the application message to the target compute node, the completion notification descriptor specifying a local memory first-in-first-out (‘FIFO’) data transfer operation for transferring data locally on the origin compute node;
• inserting, by the origin DMA engine in an injection FIFO buffer for the origin DMA engine, the data descriptor followed by the completion notification descriptor;
• 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 transfer of the application message is complete in dependence upon the completion notification descriptor.

A computer program product for signaling completion of a message transfer from an origin compute node to a target compute node, the computer program product disposed upon a computer readable medium that is not a signal, the computer program product comprising computer program instructions that when executed perform the steps of:

• sending, by an origin Direct Memory Access (‘DMA’) engine on an origin compute node to a target DMA engine on a target compute node, a request to send message on behalf of an application on the origin compute node, the request to send message specifying an application message for transfer to the target compute node from the origin compute node;
• receiving, by the origin DMA engine from the target DMA engine, a remote get message containing a data descriptor for the application message and a completion notification descriptor, the data descriptor specifying a data transfer operation for transferring the application message to the target compute node, the completion notification descriptor specifying a local memory first-in-first-out (‘FIFO’) data transfer operation for transferring data locally on the origin compute node;
• inserting, by the origin DMA engine in an injection FIFO buffer for the origin DMA engine, the data descriptor followed by the completion notification descriptor;
• 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 transfer of the application message is complete in dependence upon the completion notification descriptor.