netdev - [net 08/11] net/mlx5: Use 128B cacheline size for 128B or larger cachelines

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Date:   Tue, 20 Feb 2018 17:18:20 -0800
From:   Saeed Mahameed <saeedm@...lanox.com>
To:     "David S. Miller" <davem@...emloft.net>
Cc:     netdev@...r.kernel.org, Daniel Jurgens <danielj@...lanox.com>,
        Saeed Mahameed <saeedm@...lanox.com>
Subject: [net 08/11] net/mlx5: Use 128B cacheline size for 128B or larger cachelines

From: Daniel Jurgens <danielj@...lanox.com>

The adapter uses the cache_line_128byte setting to set the bounds for
end padding. On systems where the cacheline size is greater than 128B
use 128B instead of the default of 64B. This results in fewer partial
cacheline writes. There's a 50% chance it will pad to the end of a 256B
cache line vs only 25% when using 64B.

Fixes: f32f5bd2eb7e ("net/mlx5: Configure cache line size for start and end padding")
Signed-off-by: Daniel Jurgens <danielj@...lanox.com>
Signed-off-by: Saeed Mahameed <saeedm@...lanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
index 2ef641c91c26..ae391e4b7070 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -551,7 +551,7 @@ static int handle_hca_cap(struct mlx5_core_dev *dev)
 		MLX5_SET(cmd_hca_cap,
 			 set_hca_cap,
 			 cache_line_128byte,
-			 cache_line_size() == 128 ? 1 : 0);
+			 cache_line_size() >= 128 ? 1 : 0);
 
 	if (MLX5_CAP_GEN_MAX(dev, dct))
 		MLX5_SET(cmd_hca_cap, set_hca_cap, dct, 1);
-- 
2.14.3