net: mscc: ocelot: minimize holes in struct ocelot_port
authorVladimir Oltean <vladimir.oltean@nxp.com>
Wed, 11 May 2022 10:06:36 +0000 (13:06 +0300)
committerJakub Kicinski <kuba@kernel.org>
Thu, 12 May 2022 23:39:17 +0000 (16:39 -0700)
commit6d0be600477089026c76fe529bd96fad4cf69c3b
tree29622a5baac7ccc0ee444bf97930c682a53ae95d
parent15f6d01e4829cd2a2dc4f02a00c51d7cec1c736d
net: mscc: ocelot: minimize holes in struct ocelot_port

Reorder members of struct ocelot_port to eliminate holes and reduce
structure size. Pahole says:

Before:

struct ocelot_port {
        struct ocelot *            ocelot;               /*     0     8 */
        struct regmap *            target;               /*     8     8 */
        bool                       vlan_aware;           /*    16     1 */

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

        const struct ocelot_bridge_vlan  * pvid_vlan;    /*    24     8 */
        unsigned int               ptp_skbs_in_flight;   /*    32     4 */
        u8                         ptp_cmd;              /*    36     1 */

        /* XXX 3 bytes hole, try to pack */

        struct sk_buff_head        tx_skbs;              /*    40    96 */
        /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
        u8                         ts_id;                /*   136     1 */

        /* XXX 3 bytes hole, try to pack */

        phy_interface_t            phy_mode;             /*   140     4 */
        bool                       is_dsa_8021q_cpu;     /*   144     1 */
        bool                       learn_ena;            /*   145     1 */

        /* XXX 6 bytes hole, try to pack */

        struct net_device *        bond;                 /*   152     8 */
        bool                       lag_tx_active;        /*   160     1 */

        /* XXX 1 byte hole, try to pack */

        u16                        mrp_ring_id;          /*   162     2 */

        /* XXX 4 bytes hole, try to pack */

        struct net_device *        bridge;               /*   168     8 */
        int                        bridge_num;           /*   176     4 */
        u8                         stp_state;            /*   180     1 */

        /* XXX 3 bytes hole, try to pack */

        int                        speed;                /*   184     4 */

        /* size: 192, cachelines: 3, members: 18 */
        /* sum members: 161, holes: 7, sum holes: 27 */
        /* padding: 4 */
};

After:

struct ocelot_port {
        struct ocelot *            ocelot;               /*     0     8 */
        struct regmap *            target;               /*     8     8 */
        struct net_device *        bond;                 /*    16     8 */
        struct net_device *        bridge;               /*    24     8 */
        const struct ocelot_bridge_vlan  * pvid_vlan;    /*    32     8 */
        phy_interface_t            phy_mode;             /*    40     4 */
        unsigned int               ptp_skbs_in_flight;   /*    44     4 */
        struct sk_buff_head        tx_skbs;              /*    48    96 */
        /* --- cacheline 2 boundary (128 bytes) was 16 bytes ago --- */
        u16                        mrp_ring_id;          /*   144     2 */
        u8                         ptp_cmd;              /*   146     1 */
        u8                         ts_id;                /*   147     1 */
        u8                         stp_state;            /*   148     1 */
        bool                       vlan_aware;           /*   149     1 */
        bool                       is_dsa_8021q_cpu;     /*   150     1 */
        bool                       learn_ena;            /*   151     1 */
        bool                       lag_tx_active;        /*   152     1 */

        /* XXX 3 bytes hole, try to pack */

        int                        bridge_num;           /*   156     4 */
        int                        speed;                /*   160     4 */

        /* size: 168, cachelines: 3, members: 18 */
        /* sum members: 161, holes: 1, sum holes: 3 */
        /* padding: 4 */
        /* last cacheline: 40 bytes */
};

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
include/soc/mscc/ocelot.h