The amount of payload per MR depends on device capabilities and
the memory registration mode in use. The new rdma_rw API hides both,
making it difficult for ULPs to determine how large their transport
send queues need to be.
Expose the MR payload information via a new API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This supports both manual mapping of lots of SGEs, as well as using MRs
from the QP's MR pool, for iWarp or other cases where it's more optimal.
For now, MRs are only used for iWARP transports. The user of the RDMA-RW
API must allocate the QP MR pool as well as size the SQ accordingly.
Thanks to Steve Wise for testing, fixing and rewriting the iWarp support,
and to Sagi Grimberg for ideas, reviews and fixes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Chuck Lever