lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 18 Feb 2019 19:33:02 +0100
From:   Håkon Bugge <>
To:     Yishai Hadas <>,
        Doug Ledford <>,
        Jason Gunthorpe <>,,
Subject: [PATCH] RDMA/mlx4: Spread completion vectors for proxy CQs

MAD packet sending/receiving is not properly virtualized in
CX-3. Hence, these are proxied through the PF driver. The proxying
uses UD QPs. The associated CQs are created with completion vector

This leads to great imbalance in CPU processing, in particular during
heavy RDMA CM traffic.

Solved by selecting the completion vector on a round-robin base.

The imbalance can be demonstrated in a bare-metal environment, where
two nodes have instantiated 8 VFs each. This using dual ported HCAs,
so we have 16 vPorts per physical server.

64 processes are associated with each vPort and creates and destroys
one QP for each of the remote 64 processes. That is, 1024 QPs per
vPort, all in all 16K QPs. The QPs are created/destroyed using the

Before this commit, we have (excluding all completion IRQs with zero

396: mlx4-1@...0:94:00.0 199126
397: mlx4-2@...0:94:00.0 1

With this commit:

396: mlx4-1@...0:94:00.0 12568
397: mlx4-2@...0:94:00.0 50772
398: mlx4-3@...0:94:00.0 10063
399: mlx4-4@...0:94:00.0 50753
400: mlx4-5@...0:94:00.0 6127
401: mlx4-6@...0:94:00.0 6114
414: mlx4-19@...0:94:00.0 6122
415: mlx4-20@...0:94:00.0 6117

The added pr_info shows:

create_pv_resources: slave:0 port:1, vector:0, num_comp_vectors:62
create_pv_resources: slave:0 port:1, vector:1, num_comp_vectors:62
create_pv_resources: slave:0 port:2, vector:2, num_comp_vectors:62
create_pv_resources: slave:0 port:2, vector:3, num_comp_vectors:62
create_pv_resources: slave:1 port:1, vector:4, num_comp_vectors:62
create_pv_resources: slave:1 port:2, vector:5, num_comp_vectors:62
create_pv_resources: slave:8 port:2, vector:18, num_comp_vectors:62
create_pv_resources: slave:8 port:1, vector:19, num_comp_vectors:62

Signed-off-by: Håkon Bugge <>
 drivers/infiniband/hw/mlx4/mad.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 936ee1314bcd..300839e7f519 100644
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -1973,6 +1973,7 @@ static int create_pv_resources(struct ib_device *ibdev, int slave, int port,
 	int ret, cq_size;
 	struct ib_cq_init_attr cq_attr = {};
+	static atomic_t comp_vect = ATOMIC_INIT(-1);
 	if (ctx->state != DEMUX_PV_STATE_DOWN)
 		return -EEXIST;
@@ -2002,6 +2003,9 @@ static int create_pv_resources(struct ib_device *ibdev, int slave, int port,
 		cq_size *= 2;
 	cq_attr.cqe = cq_size;
+	cq_attr.comp_vector = atomic_inc_return(&comp_vect) % ibdev->num_comp_vectors;
+	pr_info("slave:%d port:%d, vector:%d, num_comp_vectors:%d\n",
+		slave, port, cq_attr.comp_vector, ibdev->num_comp_vectors);
 	ctx->cq = ib_create_cq(ctx->ib_dev, mlx4_ib_tunnel_comp_handler,
 			       NULL, ctx, &cq_attr);
 	if (IS_ERR(ctx->cq)) {

Powered by blists - more mailing lists