ibv_post_send
Posts a list of work requests (WR) to a send queue.
Syntax
Description
The ibv_post_recv() function posts the linked list of work requests (WR) starting with the wr parameter to the receive queue of the queue pair qp. The function stops processing the WRs from the list after detecting the first failure while requests are being posted, and returns the failing WR by using the bad_wr parameter.
The wr argument is an ibv_send_wr struct
that is defined in the <rdma/verbs.h> file.
The
transport service types for the operation codes that RC supports,
follow:
| OPCODE | IBV_QPT_RC |
|---|---|
| IBV_WR_SEND | Supported |
| IBV_WR_SEND_WITH_IMM | Supported |
| IBV_WR_RDMA_WRITE | Supported |
| IBV_WR_RDMA_WRITE_WITH_IMM | Supported |
| IBV_WR_RDMA_READ | Supported |
| IBV_WR_ATOMIC_CMP_AND_SWP | Not supported |
| IBV_WR_ATOMIC_FETCH_AND_ADD | Not supported |
The attribute
send_flags describes
the properties of the WR. It is either 0 or the bitwise OR of one
or more of the following flags:- IBV_SEND_FENCE
- Sets the fence indicator. The IBV_SEND_FENCE flag is valid only for QPs with the transport service type IBV_QPT_RC.
- IBV_SEND_SIGNALED
- Sets the completion notification indicator. The IBV_SEND_SIGNALED
flag is relevant only if QP is created with the
sq_sig_allparameter equal to 0. - IBV_SEND_SOLICITED
- Sets the solicited event indicator. The IBV_SEND_SOLICITED flag is valid only for send and remote device memory access (RDMA) write functions with immediate effect.
- IBV_SEND_INLINE
- Sends data in given gather list as inline data in a send WQE.
The IBV_SEND_INLINE flag is valid only for send and RDMA write functions.
The
L_Keyparameter is not verified.
Note: The buffers used by a WR can be safely reused
after the request is complete. A work completion is retrieved from
the corresponding completion queue (CQ).
Input Parameters
| Item | Descriptor |
|---|---|
| qp | Specifies the ibv_qp struct
for the ibv_create_qp function. |
| wr | Specifies the first work request (WR). |
Output Parameter
| Item | Descriptor |
|---|---|
| bad_wr | Specifies the pointer to the first rejected WR. |
Return Values
| Item | Descriptor |
|---|---|
| 0 | On success. |
| errno | On failure. |