rdma_reg_read
Registers the data buffer for remote direct memory access (RDMA) read access.
Syntax
Description
Registers a memory buffer that
is accessed by a remote direct memory access (RDMA) read operation.
Memory buffers that are registered by using the rdma_reg_read operation
can be targeted in an RDMA read request. The memory buffer is specified
on the remote side of an RDMA connection as the remote_addr parameter
of rdma_post_read operation, or a similar operation.
Notes:
The rdma_reg_read operation registers a data buffer that is
the target of an RDMA read operation on a queue pair that is associated
with an rdma_cm_id identifier. The memory buffer is registered
with the protection domain that is associated with the identifier.
The start of the data buffer array is specified by using the addr parameter,
and the total size of the array is specified by the length parameter.
All data buffers must be registered before being posted as a work
request. You must unregister all the registered memory by using the rdma_dereg_mr operation.
Parameters
| Item | Description |
|---|---|
| addr | Specifies the address of the memory buffer to register. |
| id | Specifies a reference to a communication identifier where the message buffer must be used. |
| length | Specifies the total length of the memory to register. |
Return Values
Returns a reference to the registered memory region on success, or NULL on error. If an error occurs, the errno is set to indicate the reason for failure.