rdma_create

Allocates a communication identifier.

Syntax

#include <rdma/rdma_cma.h>
int rdma_create_id(struct rdma_event_channel *channel, struct rdma_cm_id **id, void *context, enum rdma_port_space ps);

The rdma_create_id function creates an identifier that is used to track communication information.

Notes:

The rdma_cm_ids are conceptually equivalent to a socket for RDMA communication. The difference is that the RDMA communication requires explicit binding to a specified RDMA device before communicating, and most operations are asynchronous in nature.
You must release the rdma_cm_id by calling the rdma_destroy_id function.

Port Spaces: RDMA_PS_TCP provides reliable, connection-oriented QP. Unlike TCP, the RDMA port space provides stream based communication.

channel	Specifies the communication channel that the events associated with the allocated rdma_cm_id are reported on.
id	Specifies a reference where the allocated communication identifier will be returned.
context	Indicates the user specified context associated with the rdma_cm_id.
ps	Specifies the RDMA port space.

The rdma_create_id function returns the following values:

0	On success.
-1	Error, see errno.
-EINVAL	If the channel or id parameter is NULL or unable to query RDMA device.
-EPROTONOSUPPORT	ps is not RDMA_PS_TCP.
-ENOMEM	There is not enough memory to allocate the id by malloc.
-ENODATA	The write operation on channel->fd failed.
-ENODEV	Unable to get the RDMA device .