Commits
Chuck Lever committed 5e9fc6a06bb
xprtrdma: Support for SG_GAP devices Some devices (such as the Mellanox CX-4) can register, under a single R_key, a set of memory regions that are not contiguous. When this is done, all the segments in a Reply list, say, can then be invalidated in a single LocalInv Work Request (or via Remote Invalidation, which can invalidate exactly one R_key when completing a Receive). This means a single FastReg WR is used to register, and one or zero LocalInv WRs can invalidate, the memory involved with RDMA transfers on behalf of an RPC. In addition, xprtrdma constructs some Reply chunks from three or more segments. By registering them with SG_GAP, only one segment is needed for the Reply chunk, allowing the whole chunk to be invalidated remotely. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>