rdma_create_qp(3) [debian man page]
RDMA_CREATE_QP(3) Librdmacm Programmer's Manual RDMA_CREATE_QP(3) NAME
rdma_create_qp - Allocate a QP. SYNOPSIS
#include <rdma/rdma_cma.h> int rdma_create_qp (struct rdma_cm_id *id, struct ibv_pd *pd, struct ibv_qp_init_attr *qp_init_attr); ARGUMENTS
id RDMA identifier. pd Optional protection domain for the QP. qp_init_attr Initial QP attributes. DESCRIPTION
Allocate a QP associated with the specified rdma_cm_id and transition it for sending and receiving. RETURN VALUE
Returns 0 on success, or -1 on error. If an error occurs, errno will be set to indicate the failure reason. NOTES
The rdma_cm_id must be bound to a local RDMA device before calling this function, and the protection domain must be for that same device. QPs allocated to an rdma_cm_id are automatically transitioned by the librdmacm through their states. After being allocated, the QP will be ready to handle posting of receives. If the QP is unconnected, it will be ready to post sends. If a protection domain is not given - pd parameter is NULL - then the rdma_cm_id will be created using a default protection domain. One default protection domain is allocated per RDMA device. The initial QP attributes are specified by the qp_init_attr parameter. The send_cq and recv_cq fields in the ibv_qp_init_attr are optional. If a send or receive completion queue is not specified, then a CQ will be allocated by the rdma_cm for the QP, along with corre- sponding completion channels. Completion channels and CQ data created by the rdma_cm are exposed to the user through the rdma_cm_id struc- ture. The actual capabilities and properties of the created QP will be returned to the user through the qp_init_attr parameter. An rdma_cm_id may only be associated with a single QP. SEE ALSO
rdma_bind_addr(3), rdma_resolve_addr(3), rdma_destroy_qp(3), ibv_create_qp(3), ibv_modify_qp(3) librdmacm 2007-05-15 RDMA_CREATE_QP(3)
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RDMA_POST_RECV(3) Librdmacm Programmer's Manual RDMA_POST_RECV(3) NAME
rdma_post_recv - post a work request to receive an incoming message. SYNOPSIS
#include <rdma/rdma_verbs.h> int rdma_post_recv (struct rdma_cm_id *id, void *context, void *addr, size_t length, struct ibv_mr *mr); ARGUMENTS
id A reference to a communication identifier where the message buffer will be posted. context User-defined context associated with the request. addr The address of the memory buffer to post. length The length of the memory buffer. mr A registered memory region associated with the posted buffer. DESCRIPTION
Posts a work request to the receive queue of the queue pair associated with the rdma_cm_id. The posted buffer will be queued to receive an incoming message sent by the remote peer. RETURN VALUE
Returns 0 on success, or -1 on error. If an error occurs, errno will be set to indicate the failure reason. NOTES
The user is responsible for ensuring that a receive buffer is posted and large enough to contain all sent data before the peer posts the corresponding send message. The message buffer must have been registered before being posted, with the mr parameter referencing the regis- tration. The buffer must remain registered until the receive completes. Messages may be posted to an rdma_cm_id only after a queue pair has been associated with it. A queue pair is bound to an rdma_cm_id after calling rdma_create_ep or rdma_create_qp, if the rdma_cm_id is allocated using rdma_create_id. The user-defined context associated with the receive request will be returned to the user through the work completion wr_id, work request identifier, field. SEE ALSO
rdma_cm(7), rdma_create_id(3), rdma_create_ep(3), rdma_create_qp(3), rdma_reg_read(3), ibv_reg_mr(3), ibv_dereg_mr(3), rdma_post_recvv(3), rdma_post_send(3) librdmacm 2010-07-19 RDMA_POST_RECV(3)