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


       #include <infiniband/verbs.h>

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


       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

       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 */


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


       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.


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


       Dotan Barak <>