выделить или освободить окно памяти (MW) (allocate or deallocate a memory window (MW))
Имя (Name)
ibv_alloc_mw, ibv_dealloc_mw - allocate or deallocate a memory
window (MW)
Синопсис (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);
Описание (Description)
ibv_alloc_mw() allocates a memory window (MW) associated with the
protection 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.
Возвращаемое значение (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 function.
ibv_dealloc_mw() returns 0 on success, or the value of errno on
failure (which indicates the failure reason).
Примечание (Note)
ibv_dereg_mr() fails if any memory window is still bound to this
MR.
Смотри также (See also)
ibv_alloc_pd(3), ibv_post_send(3), ibv_bind_mw(3), ibv_reg_mr(3),
