Abstract: A computing or controlling apparatus includes a remote direct memory access (RDMA) adapter device. Responsive to an initialized state, a create queue pair adapter device command is provided by a host processing unit. The adapter device processes the command to create a queue pair in the initialized state. Responsive to a ready to send (RTS) state, a queue pair state transition command is provided by the host processing unit. The adapter device processes the queue pair state transition command to transition the queue pair from the initialized state to the ready to send (RTS) state skipping over the ready to receive (RTR) state. However, if the adapter device processes a ready to receive (RTR) in-band RDMA WQE received from the host processing unit, the state of the queue pair transitions from the initialized state to the RTR state.

Abstract: Tunneling packets of one or more remote direct memory access (RDMA) unreliable queue pairs of a first adapter device through an RDMA reliable connection (RC) by using RDMA reliable queue context and RDMA unreliable queue context stored in the first adapter device. The RDMA reliable connection is initiated between a first RDMA RC queue pair of the first adapter device and a second RDMA RC queue pair of a second adapter device. The RDMA reliable queue context is for the first RDMA RC queue pair, and the RDMA unreliable queue context is for the one or more RDMA unreliable queue pairs of the first adapter device.

Abstract: A remote direct memory access (RDMA) host device having a host operating system and an RDMA network communication adapter device. Responsive to determination of an RDMA on-load event for an RDMA queue used in an RDMA connection, at least one of a user-mode module and the operating system of the host device is used to provide an RDMA on-load notification to the RDMA network communication adapter device. The on-load notification notifies the adapter device of the determination of the on-load event for the RDMA queue, and the determination is performed by at least one of the user-mode module and the operating system. During processing of an RDMA transaction of the RDMA queue in a case where the RDMA on-load event is determined, the operating system is used to perform at least one RDMA sub-process of the RDMA transaction.

Abstract: An RDMA transceiving system in which an operating system of the RDMA transceiving system performs a first sub-process of an RDMA transmission, and an RDMA network communication adapter device of the RDMA transceiving system performs a second sub-process of the RDMA transmission responsive to RDMA transmission information provided by the operating system. The operating system performs the first sub-process responsive to a request that includes a virtual address corresponding to a buffer to be used for the RDMA transmission, and the operating system translates the virtual address into a physical address. The RDMA network communication adapter device performs an RDMA access responsive to the physical address.