Patent ID: 7836143

Claim:
A computer-implemented method for message communications of particular message types between compute nodes using DMA shadow buffers, the method comprising: receiving, in an origin messaging module on an origin compute node, a buffer identifier specifying an application buffer having a message of a particular message type for transmission to a target compute node through a data communications network; selecting, by the origin messaging module, one of a plurality of shadow buffers for an origin direct memory access (‘DMA’) engine on the origin compute node for storing the message, each shadow buffer corresponding to a slot of an injection first-in-first-out (‘FIFO’) buffer maintained by the origin DMA engine for storing data descriptors specifying messages stored in that shadow buffer; storing, by the origin messaging module, the message in the selected shadow buffer; creating, by the origin messaging module, a data descriptor for the message stored in the selected shadow buffer; injecting, by the origin messaging module, the data descriptor into the slot of the injection FIFO buffer corresponding to the selected shadow buffer; selecting, by the origin DMA engine, the data descriptor from the injection FIFO buffer; and transmitting, by the origin DMA engine to the target compute node, the message specified by the selected data descriptor through the data communications network.