I/O protocol for highly configurable multi-node processing system

An apparatus for transferring data from a first node in a multi-processor system comprising a plurality of nodes coupled to an interconnect fabric, the nodes comprising a plurality of compute nodes and a plurality of I/O nodes, each I/O node coupled to a plurality of data storage devices, the apparatus comprising:

• means for generating an I/O request packet in a first node in response to an I/O request from an application executing in the first node, the I/O packet having
• a data transfer request;
• an interconnect destination channel program;
• a first debit ID designating a second node buffer where the data request will be transmitted;
• a first credit ID designating a first node buffer where data responsive to the I/O request will be transmitted;
• means for transmitting the data request packet to a second node via the interconnect fabric;
• and
• means for executing the destination interconnect channel program to extract the debit ID to transfer the data request to the second node buffer.

A program storage device, readable by a computer, tangibly embodying one or more programs of instructions executable by the computer to perform method steps of transferring data from a first node to a second node in a multi-processor system comprising a plurality of nodes coupled to an interconnect fabric, the nodes comprising a plurality of compute nodes and a plurality of I/O nodes, each I/O node coupled to a plurality of data storage devices, the method comprising the steps of:

• generating a I/O request packet in a first node in response to an I/O request from an application executing in the first node, the I/O packet having
• a data transfer request;
• an interconnect destination-side channel program;
• a first debit ID designating a second node buffer where the data request will be transmitted;
• and
• a first credit ID designating a first node buffer where the data responsive to the I/O request will be transmitted;
• transmitting the data request packet to a second node via the interconnect fabric;
• and
• executing the destination-side interconnect channel program to extract the debit ID to transfer the data request to the second node buffer.

A data structure for transceiving payload data from a first node to a second node in a multiprocessor system, comprising:

• a payload portion, having payload data;
• a header portion, having
• an interconnect channel program for processing the data packet at a second node interface having a second node buffer;
• a debit field for storing a first ID designating a location in the second node buffer where an I/O request will be transmitted;
• and
• a credit field for storing a second ID designating a location in a first node buffer where data responsive to the I/O request will be transmitted.

A method of transferring data from a first node to a second node in a multi-processor system comprising a plurality of nodes coupled to an interconnect fabric, the nodes comprising a plurality of compute nodes and a plurality of I/O nodes, each I/O node coupled to a plurality of data storage devices, the method comprising the steps of:

• generating a I/O request packet in a first node in response to an I/O request from an application executing in the first node, the I/O packet having
• a data transfer request;
• an interconnect destination-side channel program;
• a first debit ID designating a second node buffer where the data request will be transmitted;
• and
• a first credit ID designating a first node buffer where the data responsive to the I/O request will be transmitted;
• and
• transmitting the data request packet to a second node via the interconnect fabric.