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IBV_ALLOC_MW(3)		Libibverbs Programmer's	Manual	       IBV_ALLOC_MW(3)

NAME
       ibv_alloc_mw,  ibv_dealloc_mw  -	allocate or deallocate a memory	window
       (MW)

SYNOPSIS
       #include	<infiniband/verbs.h>

       struct ibv_mw *ibv_alloc_mw(struct ibv_pd *pd,
				   enum	ibv_mw_type type);

       int ibv_dealloc_mw(struct ibv_mw	*mw);

DESCRIPTION
       ibv_alloc_mw() allocates	a memory window	(MW) associated	with the  pro-
       tection domain pd.  The MW's type (1 or 2A/2B) is type.

       The MW is created not bound. For	it to be useful, the MW	must be	bound,
       through either ibv_bind_mw (type	1) or a	special	 WR  (type  2).	  Once
       bound, the memory window	allows RDMA (remote) access to a subset	of the
       MR to which it was bound, until invalidated by: ibv_bind_mw  verb  with
       zero length for type 1, IBV_WR_LOCAL_INV/IBV_WR_SEND_WITH_INV WR	opcode
       for type	2, deallocation.

       ibv_dealloc_mw()	Unbinds	in case	was previously bound  and  deallocates
       the MW mw.

RETURN VALUE
       ibv_alloc_mw()  returns	a  pointer to the allocated MW,	or NULL	if the
       request fails.  The remote key (R_Key) field rkey  is  used  by	remote
       processes  to  perform  Atomic  and  RDMA  operations. This key will be
       changed during bind operations. The remote process places this rkey  as
       the  rkey field of struct ibv_send_wr passed to the ibv_post_send func-
       tion.

       ibv_dealloc_mw()	returns	0 on success, or the value of errno on failure
       (which indicates	the failure reason).

NOTES
       ibv_dereg_mr() fails if any memory window is still bound	to this	MR.

SEE ALSO
       ibv_alloc_pd(3),	ibv_post_send(3), ibv_bind_mw(3), ibv_reg_mr(3),

AUTHORS
       Majd Dibbiny <majd@mellanox.com>

       Yishai Hadas <yishaih@mellanox.com>

libibverbs			  2016-02-02		       IBV_ALLOC_MW(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | AUTHORS

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