diff mbox series

[net,1/4] net/mlx5: DR, select MSIX vector 0 for completion queue creation

Message ID 20241220081505.1286093-2-tariqt@nvidia.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series mlx5 misc fixes 2024-12-20 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: linux-rdma@vger.kernel.org
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-12-20--09-00 (tests: 879)

Commit Message

Tariq Toukan Dec. 20, 2024, 8:15 a.m. UTC 
From: Shahar Shitrit <shshitrit@nvidia.com>

When creating a software steering completion queue (CQ), an arbitrary
MSIX vector n is selected. This results in the CQ sharing the same
Ethernet traffic channel n associated with the chosen vector. However,
the value of n is often unpredictable, which can introduce complications
for interrupt monitoring and verification tools.

Moreover, SW steering uses polling rather than event-driven interrupts.
Therefore, there is no need to select any MSIX vector other than the
existing vector 0 for CQ creation.

In light of these factors, and to enhance predictability, we modify the
code to consistently select MSIX vector 0 for CQ creation.

Fixes: 297cccebdc5a ("net/mlx5: DR, Expose an internal API to issue RDMA operations")
Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/steering/sws/dr_send.c    | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/sws/dr_send.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/sws/dr_send.c
index 6fa06ba2d346..f57c84e5128b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/sws/dr_send.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/sws/dr_send.c
@@ -1067,7 +1067,6 @@  static struct mlx5dr_cq *dr_create_cq(struct mlx5_core_dev *mdev,
 	int inlen, err, eqn;
 	void *cqc, *in;
 	__be64 *pas;
-	int vector;
 	u32 i;
 
 	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
@@ -1096,8 +1095,7 @@  static struct mlx5dr_cq *dr_create_cq(struct mlx5_core_dev *mdev,
 	if (!in)
 		goto err_cqwq;
 
-	vector = raw_smp_processor_id() % mlx5_comp_vectors_max(mdev);
-	err = mlx5_comp_eqn_get(mdev, vector, &eqn);
+	err = mlx5_comp_eqn_get(mdev, 0, &eqn);
 	if (err) {
 		kvfree(in);
 		goto err_cqwq;