Memory Controller Reservation of Retry Queue

A method, comprising:

• receiving, by an arbitration circuit within a memory controller circuit, a memory access request originating from a network of a computer system implemented on one or more co-packaged integrated circuit dies;
• reserving, by the arbitration circuit for the memory access request, an entry in a retry queue circuit of the memory controller circuit, the retry queue circuit being configured to store information relating to memory access requests that are not able to complete a given pass through the memory controller circuit and are to be rescheduled with the arbitration circuit for an additional pass, wherein the reserving guarantees that a lack of availability of the retry queue circuit will not cause the memory access request to be returned to the network for resubmission to the arbitration circuit;
• arbitrating, by the arbitration circuit, between a group of memory access requests to the memory controller circuit;
• selecting, by the arbitration circuit, the memory access request as a result of the arbitrating, wherein an entry in the retry queue circuit has been reserved for the selected memory access request;
• and
• initiating, by the arbitration circuit, a pass through the memory controller circuit for the memory access request.

A system, comprising:

• a computer system implemented on one or more co-packaged integrated circuit dies, the computer system including:
• a plurality of memory plane controller circuits, wherein a given memory plane controller circuit includes:
• an arbitration circuit configured to receive a memory access request originating from one of a plurality of networks of the computer system;
• memory circuitry;
• and
• a retry queue circuit having a plurality of entries configured to store information for memory access requests that, during a given pass through the memory circuitry, are determined to require an additional pass through the memory circuitry following resubmission to the arbitration circuit by the retry queue circuit;
• and
• wherein the arbitration circuit is configured to:
• reserve an entry in the retry queue circuit for the memory access request, wherein the reserved entry ensures that a lack of availability of the retry queue circuit will not cause the memory access request to be returned for resubmission to a particular one of the plurality of networks from which the memory access request originated;
• and
• select the memory access request for issuance to the memory circuitry as a result of an arbitration process between memory access requests having reserved entries in the retry queue circuit.