From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Mon, 12 Feb 2018 09:50:25 -0800
Subject: IB/srp: Fix completion vector assignment algorithm
Patch-mainline: v4.17-rc1
Git-commit: 3a148896b24adf8688dc0c59af54531931677a40
References: bsc#1046306 FATE#322942
Ensure that cv_end is equal to ibdev->num_comp_vectors for the
NUMA node with the highest index. This patch improves spreading
of RDMA channels over completion vectors and thereby improves
performance, especially on systems with only a single NUMA node.
This patch drops support for the comp_vector login parameter by
ignoring the value of that parameter since I have not found a
good way to combine support for that parameter and automatic
spreading of RDMA channels over completion vectors.
Fixes: d92c0da71a35 ("IB/srp: Add multichannel support")
Reported-by: Alexander Schmid <alex@modula-shop-systems.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Alexander Schmid <alex@modula-shop-systems.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/ulp/srp/ib_srp.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -3428,12 +3428,10 @@ static ssize_t srp_create_target(struct
num_online_nodes());
const int ch_end = ((node_idx + 1) * target->ch_count /
num_online_nodes());
- const int cv_start = (node_idx * ibdev->num_comp_vectors /
- num_online_nodes() + target->comp_vector)
- % ibdev->num_comp_vectors;
- const int cv_end = ((node_idx + 1) * ibdev->num_comp_vectors /
- num_online_nodes() + target->comp_vector)
- % ibdev->num_comp_vectors;
+ const int cv_start = node_idx * ibdev->num_comp_vectors /
+ num_online_nodes();
+ const int cv_end = (node_idx + 1) * ibdev->num_comp_vectors /
+ num_online_nodes();
int cpu_idx = 0;
for_each_online_cpu(cpu) {