diff mbox series

[net-next,02/16] net/mlx5: E-Switch, cut down mlx5_vport_info structure size by 8 bytes

Message ID 20210404041954.146958-3-saeed@kernel.org
State New
Headers show
Series mlx5 updates 2021-04-02 | expand

Commit Message

Saeed Mahameed April 4, 2021, 4:19 a.m. UTC 
From: Parav Pandit <parav@nvidia.com>

Structure mlx5_vport_info consumes 40 bytes of space due to a hole
in it. After packing it reduces to 32 bytes.

Currently:
pahole -C mlx5_vport_info drivers/net/ethernet/mellanox/mlx5/core/eswitch.o
struct mlx5_vport_info {
        u8                         mac[6];               /*     0     6 */
        u16                        vlan;                 /*     6     2 */
        u8                         qos;                  /*     8     1 */

        /* XXX 7 bytes hole, try to pack */

        u64                        node_guid;            /*    16     8 */
        int                        link_state;           /*    24     4 */
        u32                        min_rate;             /*    28     4 */
        u32                        max_rate;             /*    32     4 */
        bool                       spoofchk;             /*    36     1 */
        bool                       trusted;              /*    37     1 */

        /* size: 40, cachelines: 1, members: 9 */
        /* sum members: 31, holes: 1, sum holes: 7 */
        /* padding: 2 */
        /* last cacheline: 40 bytes */
};

After packing:

$ pahole -C mlx5_vport_info drivers/net/ethernet/mellanox/mlx5/core/eswitch.o

struct mlx5_vport_info {
        u8                         mac[6];               /*     0     6 */
        u16                        vlan;                 /*     6     2 */
        u64                        node_guid;            /*     8     8 */
        int                        link_state;           /*    16     4 */
        u32                        min_rate;             /*    20     4 */
        u32                        max_rate;             /*    24     4 */
        u8                         qos;                  /*    28     1 */
        u8                         spoofchk:1;           /*    29: 0  1 */
        u8                         trusted:1;            /*    29: 1  1 */

        /* size: 32, cachelines: 1, members: 9 */
        /* padding: 2 */
        /* bit_padding: 6 bits */
        /* last cacheline: 32 bytes */
};

Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/eswitch.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index 56d85cedb9bd..0adffab20244 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -118,13 +118,13 @@  struct mlx5_vport_drop_stats {
 struct mlx5_vport_info {
 	u8                      mac[ETH_ALEN];
 	u16                     vlan;
-	u8                      qos;
 	u64                     node_guid;
 	int                     link_state;
 	u32                     min_rate;
 	u32                     max_rate;
-	bool                    spoofchk;
-	bool                    trusted;
+	u8                      qos;
+	u8                      spoofchk: 1;
+	u8                      trusted: 1;
 };
 
 /* Vport context events */