System and method for transferring data over a remote direct memory access (RDMA) network
View Patent ↗Systems and methods that provide one-shot remote direct memory access (RDMA) are provided. In one embodiment, a system that transfers data over an RDMA network may include, for example, a host. The host may include, for example, a driver and a network interface card (NIC), the driver being coupled to the NIC. The driver and the NIC may perform a one-shot initiation process and/or a one-shot completion process of an RDMA operation.
1. A system for transferring data over a remote direct memory access (RDMA) network, comprising:
a host comprising a driver and a network interface card (NIC), the driver being coupled to the NIC,
wherein a one-shot initiation process of an RDMA operation is performed between the driver and the NIC of the host, the one-shot initiation process comprising communicating a single command message comprising:
buffer command information, and
a write command to write a send command.
2. The system according to claim 1 , wherein the driver posts the single command message to perform the one-shot initiation process.
3. The system according to claim 1 , wherein the buffer command information comprises a command to describe pinned-down memory buffers of the host.
4. The system according to claim 3 , wherein the buffer command information comprises a command to bind a portion of the pinned-down memory buffers of the host to a steering tag (STag).
5. The system according to claim 1 , wherein the send command is an RDMA send message.
6. The system according to claim 4 , wherein the NIC places the STag value in an optional field in a direct data placement DDP or RDMA header.
7. The system according to claim 6 , wherein the NIC encodes a value into a field in the DDP or RDMA header indicating that the STag value in the optional field is valid.
8. The system according to claim 6 , wherein the NIC sets one or more bits in a field in the DDP or RDMA header indicating that the STag value in the optional field is valid.
9. The system according to claim 6 , wherein the NIC sets one or more bits or encodes a value into a second field in the DDP or RDMA header to advertise the portion of the pinned memory buffers of the host associated with the STag.
10. The system according to claim 1 , wherein the buffer command information provides a description of a section of memory.
11. The system according to claim 1 , wherein the single command message is posted to a command ring of the host.
12. The system according to claim 11 , wherein the driver allocates an STag value.
13. The system according to claim 12 , wherein the STag value is returned synchronously from a command call.
14. The system according to claim 12 , wherein the STag value is saved in a driver command table of the host.
15. The system according to claim 14 , wherein the STag value saved in a driver command table is associated with an application reference number.
16. The system according to claim 1 , wherein the NIC comprises an RDMA-enabled NIC.
17. A system for transferring data over a remote direct memory access (RDMA) network, comprising:
a host comprising a driver and a network interface card (NIC), the driver being coupled to the NIC,
wherein a one-shot completion process of an RDMA operation is performed between the driver and the NIC of the host, the one-shot completion process comprising communicating a single completion message comprising:
a send complete indication, and
buffer freeing status information.
18. The system according to claim 17 , wherein the NIC receives a message comprising an optional field carrying a STag value, the STag value being associated with pinned memory in a remote host.
19. The system according to claim 18 , wherein a header of the message indicates the validity of the optional field with a bit flag or specified value in an encoded field.
20. The system according to claim 18 , wherein the NIC de-associates the STag value with the pinned memory in the host, thereby preventing further access to the pinned memory using the de-associated STag value.
21. The system according to claim 18 ,
wherein the single completion message comprises the optional field carrying the STag value received by the NIC;
wherein the NIC delivers the single completion message to the driver, and
wherein the driver compares the STag value received with a STag value previously sent.
22. The system according to claim 18 , wherein the NIC de-associates the STag value with previously associated SGL information.
23. The system according to claim 20 , wherein the NIC frees any resources dedicated to information regarding the pinned memory.
24. A method for transferring data over an RDMA network, comprising:
initiating an RDMA write operation using a one-shot initiation process between a driver and a NIC of a host, wherein the one-shot initiation process comprises communicating a single command message comprising:
buffer command information comprising commands to insert and validate an STag value, and
a write command to write an RDMA send message;
inserting the STag value in a first field of a DDP or RDMA header of the RDMA send message; and
validating the STag value in the first field with a bit flag or other specified value in a second field of the DDP or RDMA header.
25. A method for transferring data over an RDMA network, comprising:
completing an RDMA write operation using a one-shot completion process between a NIC and a driver of a host, wherein the one-shot completion process comprises communicating a single completion message comprising:
a send complete indication,
buffer freeing status information, and
an STag value;
receiving the single completion message;
identifying the STag value in a first field of a header of the single completion message; and
validating the STag value in the first field of the header by identifying a bit flag or other specified value in a second field of the header.