rdma: Enable ib_alloc_cq to spread work over a device's comp_vectors

Send and Receive completion is handled on a single CPU selected at
the time each Completion Queue is allocated. Typically this is when
an initiator instantiates an RDMA transport, or when a target
accepts an RDMA connection.

Some ULPs cannot open a connection per CPU to spread completion
workload across available CPUs and MSI vectors. For such ULPs,
provide an API that allows the RDMA core to select a completion
vector based on the device's complement of available comp_vecs.

ULPs that invoke ib_alloc_cq() with only comp_vector 0 are converted
to use the new API so that their completion workloads interfere less
with each other.

Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Cc: <linux-cifs@vger.kernel.org>
Cc: <v9fs-developer@lists.sourceforge.net>
Link: https://lore.kernel.org/r/20190729171923.13428.52555.stgit@manet.1015granger.net
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index bac8dad5dd69..b21c3c209815 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -685,9 +685,9 @@ rdma_create_trans(struct p9_client *client, const char *addr, char *args)
 		goto error;
 
 	/* Create the Completion Queue */
-	rdma->cq = ib_alloc_cq(rdma->cm_id->device, client,
-			opts.sq_depth + opts.rq_depth + 1,
-			0, IB_POLL_SOFTIRQ);
+	rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
+				   opts.sq_depth + opts.rq_depth + 1,
+				   IB_POLL_SOFTIRQ);
 	if (IS_ERR(rdma->cq))
 		goto error;