.\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
.TH "RDMA_DEREG_MR" 3 "2010-07-19" "librdmacm" "Librdmacm Programmer's Manual" librdmacm
.SH NAME
rdma_dereg_mr \- deregisters a registered memory region.
.SH SYNOPSIS
.B "#include <rdma/rdma_verbs.h>"
.P
.B "struct ibv_mr *" rdma_dereg_mr
.BI "(struct ibv_mr *" mr ");"
.SH ARGUMENTS
.IP "mr" 12
A reference to a registered memory buffer.
.SH "DESCRIPTION"
Deregisters a memory buffer that had been registered for RDMA
or message operations.  A user should call rdma_dereg_mr for all
registered memory associated with an rdma_cm_id before destroying
the rdma_cm_id.
.SH "RETURN VALUE"
Returns 0 on success, or -1 on error.  If an error occurs, errno will be
set to indicate the failure reason.
.SH "NOTES"
All memory registered with an rdma_cm_id is associated with the
protection domain associated with the id.  Users must deregister
all registered memory before the protection domain can be destroyed.
.SH "SEE ALSO"
rdma_cm(7), rdma_create_id(3), rdma_create_ep(3),
rdma_destroy_id(3), rdma_destroy_ep(3),
rdma_reg_msgs(3), rdma_reg_read(3), rdma_reg_write(3),
ibv_reg_mr(3), ibv_dereg_mr(3)