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

@@ -136,7 +136,7 @@ isert_create_qp(struct isert_conn *isert_conn,
attr.cap.max_send_wr = ISERT_QP_MAX_REQ_DTOS + 1;
attr.cap.max_recv_wr = ISERT_QP_MAX_RECV_DTOS + 1;
attr.cap.max_rdma_ctxs = ISCSI_DEF_XMIT_CMDS_MAX;
attr.cap.max_send_sge = device->ib_device->attrs.max_sge;
attr.cap.max_send_sge = device->ib_device->attrs.max_send_sge;
attr.cap.max_recv_sge = 1;
attr.sq_sig_type = IB_SIGNAL_REQ_WR;
attr.qp_type = IB_QPT_RC;
@@ -299,7 +299,8 @@ isert_create_device_ib_res(struct isert_device *device)
struct ib_device *ib_dev = device->ib_device;
int ret;
isert_dbg("devattr->max_sge: %d\n", ib_dev->attrs.max_sge);
isert_dbg("devattr->max_send_sge: %d devattr->max_recv_sge %d\n",
ib_dev->attrs.max_send_sge, ib_dev->attrs.max_recv_sge);
isert_dbg("devattr->max_sge_rd: %d\n", ib_dev->attrs.max_sge_rd);
ret = isert_alloc_comps(device);