Commit 3a148896 authored Feb 12, 2018 by Bart Van Assche Committed by Jason Gunthorpe Feb 15, 2018

IB/srp: Fix completion vector assignment algorithm



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: d92c0da7 ("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>

parent 71591d12

drivers/infiniband/ulp/srp/ib_srp.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -3871,12 +3871,10 @@ static ssize_t srp_create_target(struct device *dev,
		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) {

Admin message