Patent ID: 8959172
Filing Date: 2015-02-17
Classification: G06F

Abstract:
1. A method for self-pacing Direct Memory Access (‘DMA’) data transfer operations for compute nodes in a parallel computer, the method comprising: transferring, by an origin DMA engine on an origin compute node, a request to send (‘RTS’) message to a target compute node, the RTS message specifying an application message on the origin compute node for transfer to the target compute node; receiving, in an origin injection first-in-first-out (‘FIFO’) buffer for the origin DMA engine from a target DMA engine on the target compute node in response to transferring the RTS message, a target RGET data descriptor followed by a DMA transfer operation data descriptor, the DMA transfer operation data descriptor specifying a DMA data transfer operation for transmitting a portion of the application message to the target compute node, the target RGET data descriptor specifying an origin RGET data descriptor on the origin compute node, the origin RGET data descriptor specifying an additional DMA transfer operation data descriptor that specifies an additional DMA data transfer operation for transmitting an additional portion of the application message to the target compute node; processing, by the origin DMA engine, the target RGET data descriptor, including transferring the origin RGET data descriptor to the target DMA engine for injection into a target injection FIFO buffer for the target DMA engine; and processing, by the origin DMA engine, the DMA transfer operation data descriptor, including transferring the portion of the application message specified by the DMA transfer operation data descriptor to the target compute node.