ibv_post_recv(3) — Linux manual page

IBV_POST_RECV(3)     Libibverbs Programmer's Manual     IBV_POST_RECV(3)

NAME

       ibv_post_recv - post a list of work requests (WRs) to a receive
       queue

SYNOPSIS

       #include <infiniband/verbs.h>

       int ibv_post_recv(struct ibv_qp *qp, struct ibv_recv_wr *wr,
                         struct ibv_recv_wr **bad_wr);

DESCRIPTION

       ibv_post_recv() posts the linked list of work requests (WRs)
       starting with wr to the receive queue of the queue pair qp.  It
       stops processing WRs from this list at the first failure (that
       can be detected immediately while requests are being posted), and
       returns this failing WR through bad_wr.

       The argument wr is an ibv_recv_wr struct, as defined in
       <infiniband/verbs.h>.

       struct ibv_recv_wr {
               uint64_t                wr_id;     /* User defined WR ID */
               struct ibv_recv_wr     *next;      /* Pointer to next WR in list, NULL if last WR */
               struct ibv_sge         *sg_list;   /* Pointer to the s/g array */
               int                     num_sge;   /* Size of the s/g array */
       };

       struct ibv_sge {
               uint64_t                addr;      /* Start address of the local memory buffer */
               uint32_t                length;    /* Length of the buffer */
               uint32_t                lkey;      /* Key of the local Memory Region */
       };

RETURN VALUE

       ibv_post_recv() returns 0 on success, or the value of errno on
       failure (which indicates the failure reason).

NOTES

       The buffers used by a WR can only be safely reused after WR the
       request is fully executed and a work completion has been
       retrieved from the corresponding completion queue (CQ).

       If the QP qp is associated with a shared receive queue, you must
       use the function ibv_post_srq_recv(), and not ibv_post_recv(),
       since the QP's own receive queue will not be used.

       If a WR is being posted to a UD QP, the Global Routing Header
       (GRH) of the incoming message will be placed in the first 40
       bytes of the buffer(s) in the scatter list.  If no GRH is present
       in the incoming message, then the first bytes will be undefined.
       This means that in all cases, the actual data of the incoming
       message will start at an offset of 40 bytes into the buffer(s) in
       the scatter list.

SEE ALSO

       ibv_create_qp(3), ibv_post_send(3), ibv_post_srq_recv(3),
       ibv_poll_cq(3)

AUTHORS

       Dotan Barak <dotanba@gmail.com>

COLOPHON

       This page is part of the rdma-core (RDMA Core Userspace Libraries
       and Daemons) project.  Information about the project can be found
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       linux-rdma@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
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libibverbs                     2006-10-31               IBV_POST_RECV(3)

Pages that refer to this page: ibv_poll_cq(3), ibv_post_send(3), ibv_post_srq_recv(3), ibv_reg_mr(3)

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