[PATCH 5.12 428/700] RDMA/rtrs-srv: Set minimal max_send_wr and max_recv_wr

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 03:51:24 EST


From: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>

[ Upstream commit 5e91eabf66c854f16ca2e954e5c68939bc81601e ]

Currently rtrs when create_qp use a coarse numbers (bigger in general),
which leads to hardware create more resources which only waste memory with
no benefits.

For max_send_wr, we don't really need alway max_qp_wr size when creating
qp, reduce it to cq_size.

For max_recv_wr, cq_size is enough.

With the patch when sess_queue_depth=128, per session (2 paths) memory
consumption reduced from 188 MB to 65MB

When always_invalidate is enabled, we need send more wr, so treat it
special.

Fixes: 9cb837480424e ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20210614090337.29557-2-jinpu.wang@xxxxxxxxx
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
Reviewed-by: Md Haris Iqbal <haris.iqbal@xxxxxxxxxxxxxxx>
Signed-off-by: Gioh Kim <gi-oh.kim@xxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/infiniband/ulp/rtrs/rtrs-srv.c | 38 +++++++++++++++++---------
1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
index 8c0acfc48392..57a9d396ab75 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1601,7 +1601,7 @@ static int create_con(struct rtrs_srv_sess *sess,
struct rtrs_sess *s = &sess->s;
struct rtrs_srv_con *con;

- u32 cq_size, wr_queue_size;
+ u32 cq_size, max_send_wr, max_recv_wr, wr_limit;
int err, cq_vector;

con = kzalloc(sizeof(*con), GFP_KERNEL);
@@ -1622,30 +1622,42 @@ static int create_con(struct rtrs_srv_sess *sess,
* All receive and all send (each requiring invalidate)
* + 2 for drain and heartbeat
*/
- wr_queue_size = SERVICE_CON_QUEUE_DEPTH * 3 + 2;
- cq_size = wr_queue_size;
+ max_send_wr = SERVICE_CON_QUEUE_DEPTH * 2 + 2;
+ max_recv_wr = SERVICE_CON_QUEUE_DEPTH + 2;
+ cq_size = max_send_wr + max_recv_wr;
} else {
- /*
- * If we have all receive requests posted and
- * all write requests posted and each read request
- * requires an invalidate request + drain
- * and qp gets into error state.
- */
- cq_size = srv->queue_depth * 3 + 1;
/*
* In theory we might have queue_depth * 32
* outstanding requests if an unsafe global key is used
* and we have queue_depth read requests each consisting
* of 32 different addresses. div 3 for mlx5.
*/
- wr_queue_size = sess->s.dev->ib_dev->attrs.max_qp_wr / 3;
+ wr_limit = sess->s.dev->ib_dev->attrs.max_qp_wr / 3;
+ /* when always_invlaidate enalbed, we need linv+rinv+mr+imm */
+ if (always_invalidate)
+ max_send_wr =
+ min_t(int, wr_limit,
+ srv->queue_depth * (1 + 4) + 1);
+ else
+ max_send_wr =
+ min_t(int, wr_limit,
+ srv->queue_depth * (1 + 2) + 1);
+
+ max_recv_wr = srv->queue_depth + 1;
+ /*
+ * If we have all receive requests posted and
+ * all write requests posted and each read request
+ * requires an invalidate request + drain
+ * and qp gets into error state.
+ */
+ cq_size = max_send_wr + max_recv_wr;
}
- atomic_set(&con->sq_wr_avail, wr_queue_size);
+ atomic_set(&con->sq_wr_avail, max_send_wr);
cq_vector = rtrs_srv_get_next_cq_vector(sess);

/* TODO: SOFTIRQ can be faster, but be careful with softirq context */
err = rtrs_cq_qp_create(&sess->s, &con->c, 1, cq_vector, cq_size,
- wr_queue_size, wr_queue_size,
+ max_send_wr, max_recv_wr,
IB_POLL_WORKQUEUE);
if (err) {
rtrs_err(s, "rtrs_cq_qp_create(), err: %d\n", err);
--
2.30.2