From: Daniel Jurgens <danielj@xxxxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 16b0e0695a73b68d8ca40288c8f9614ef208917b upstream. When creating kernel CQs use 128B CQE stride if the cache line size is 128B, 64B otherwise. This prevents multiple CQEs from residing in a 128B cache line, which can cause retries when there are concurrent read and writes in one cache line. Tested with IPoIB on PPC64, saw ~5% throughput improvement. Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters') Signed-off-by: Daniel Jurgens <danielj@xxxxxxxxxxxx> Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx> Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx> Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/infiniband/hw/mlx5/cq.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/cq.c b/drivers/infiniband/hw/mlx5/cq.c index 706833ab7e7e..e5a6d839f1d1 100644 --- a/drivers/infiniband/hw/mlx5/cq.c +++ b/drivers/infiniband/hw/mlx5/cq.c @@ -684,8 +684,7 @@ struct ib_cq *mlx5_ib_create_cq(struct ib_device *ibdev, int entries, if (err) goto err_create; } else { - /* for now choose 64 bytes till we have a proper interface */ - cqe_size = 64; + cqe_size = cache_line_size() == 128 ? 128 : 64; err = create_cq_kernel(dev, cq, entries, cqe_size, &cqb, &index, &inlen); if (err) -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html