| From 3a148896b24adf8688dc0c59af54531931677a40 Mon Sep 17 00:00:00 2001 |
| 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 |
| |
| From: Bart Van Assche <bart.vanassche@wdc.com> |
| |
| commit 3a148896b24adf8688dc0c59af54531931677a40 upstream. |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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 |
| @@ -3430,12 +3430,10 @@ 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) { |
