rdma_create_ep man page

rdma_create_ep — Allocate a communication identifier and optional QP.


#include <rdma/rdma_cma.h>

int rdma_create_ep (struct rdma_cm_id **id, struct rdma_addrinfo *res, struct ibv_pd  *pd, struct ibv_qp_init_attr *qp_init_attr);



A reference where the allocated communication identifier will be returned.


Address information associated with the rdma_cm_id returned from rdma_getaddrinfo.


Optional protection domain if a QP is associated with the rdma_cm_id.


Optional initial QP attributes.


Creates an identifier that is used to track communication information.

Return Value

Returns 0 on success, or -1 on error.  If an error occurs, errno will be set to indicate the failure reason.


After resolving address information using rdma_getaddrinfo, a user may use this call to allocate an rdma_cm_id based on the results.

If the rdma_cm_id will be used on the active side of a connection, meaning that res->ai_flag does not have RAI_PASSIVE set, rdma_create_ep will automatically create a QP on the rdma_cm_id if qp_init_attr is not NULL.  The QP will be associated with the specified protection domain, if provided, or a default protection domain if not.  Users should see rdma_create_qp for details on the use of the pd and qp_init_attr parameters.  After calling rdma_create_ep, the returned rdma_cm_id may be connected by calling rdma_connect.  The active side calls rdma_resolve_addr and rdma_resolve_route are not necessary.

If the rdma_cm_id will be used on the passive side of a connection, indicated by having res->ai_flag RAI_PASSIVE set, this call will save the provided pd and qp_init_attr parameters.  When a new connection request is retrieved by calling rdma_get_request, the rdma_cm_id associated with the new connection will automatically be associated with a QP using the pd and qp_init_attr parameters.  After calling rdma_create_ep, the returned rdma_cm_id may be placed into a listening state by immediately calling rdma_listen.  The passive side call rdma_bind_addr is not necessary.  Connection requests may then be retrieved by calling rdma_get_request.

The newly created rdma_cm_id will be set to use synchronous operation. Users that wish asynchronous operation must migrate the rdma_cm_id to a user created event channel using rdma_migrate_id.

Users must release the created rdma_cm_id by calling rdma_destroy_ep.

See Also

rdma_cm(7), rdma_getaddrinfo(3), rdma_create_event_channel(3), rdma_connect(3), rdma_listen(3), rdma_destroy_ep(3), rdma_migrate_id(3)

Referenced By

rdma_cm(7), rdma_create_srq(3), rdma_dereg_mr(3), rdma_destroy_ep(3), rdma_getaddrinfo(3), rdma_post_recv(3), rdma_post_recvv(3), rdma_reg_msgs(3), rdma_reg_read(3), rdma_reg_write(3).

2010-07-19 librdmacm Librdmacm Programmer's Manual