linux

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John Fastabend e014860e31 net: pack tc_cls_u32_knode struct slighter better

By packing the structure we can remove a few holes as Jamal
suggests.

before:

struct tc_cls_u32_knode {
	struct tcf_exts *          exts;                 /*     0     8 */
	u8                         fshift;               /*     8     1 */

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

	u32                        handle;               /*    12     4 */
	u32                        val;                  /*    16     4 */
	u32                        mask;                 /*    20     4 */
	u32                        link_handle;          /*    24     4 */

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

	struct tc_u32_sel *        sel;                  /*    32     8 */

	/* size: 40, cachelines: 1, members: 7 */
	/* sum members: 33, holes: 2, sum holes: 7 */
	/* last cacheline: 40 bytes */
};

after:

struct tc_cls_u32_knode {
	struct tcf_exts *          exts;                 /*     0     8 */
	struct tc_u32_sel *        sel;                  /*     8     8 */
	u32                        handle;               /*    16     4 */
	u32                        val;                  /*    20     4 */
	u32                        mask;                 /*    24     4 */
	u32                        link_handle;          /*    28     4 */
	u8                         fshift;               /*    32     1 */

	/* size: 40, cachelines: 1, members: 7 */
	/* padding: 7 */
	/* last cacheline: 40 bytes */
};

Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2016-02-17 21:44:12 -05:00