IB/core: add max_send_sge and max_recv_sge attributes

This patch replaces the ib_device_attr.max_sge with max_send_sge and
max_recv_sge. It allows ulps to take advantage of devices that have very
different send and recv sge depths.  For example cxgb4 has a max_recv_sge
of 4, yet a max_send_sge of 16.  Splitting out these attributes allows
much more efficient use of the SQ for cxgb4 with ulps that use the RDMA_RW
API. Consider a large RDMA WRITE that has 16 scattergather entries.
With max_sge of 4, the ulp would send 4 WRITE WRs, but with max_sge of
16, it can be done with 1 WRITE WR.

Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Steve Wise
2018-06-18 08:05:26 -07:00
committed by Jason Gunthorpe
parent b90575ce7b
commit 33023fb85a
28 changed files with 65 additions and 39 deletions

View File

@@ -1753,13 +1753,15 @@ retry:
*/
qp_init->cap.max_send_wr = min(sq_size / 2, attrs->max_qp_wr);
qp_init->cap.max_rdma_ctxs = sq_size / 2;
qp_init->cap.max_send_sge = min(attrs->max_sge, SRPT_MAX_SG_PER_WQE);
qp_init->cap.max_send_sge = min(attrs->max_send_sge,
SRPT_MAX_SG_PER_WQE);
qp_init->port_num = ch->sport->port;
if (sdev->use_srq) {
qp_init->srq = sdev->srq;
} else {
qp_init->cap.max_recv_wr = ch->rq_size;
qp_init->cap.max_recv_sge = qp_init->cap.max_send_sge;
qp_init->cap.max_recv_sge = min(attrs->max_recv_sge,
SRPT_MAX_SG_PER_WQE);
}
if (ch->using_rdma_cm) {