lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

vlan: Don't store VLAN tag in cb

Browse Source 
Use a real skb member to store the skb to avoid clashes with qdiscs,
which are allowed to use the cb area themselves. As currently only real
devices that consume the skb set the NETIF_F_HW_VLAN_TX flag, no explicit
invalidation is neccessary.

The new member fills a hole on 64 bit, the skb layout changes from:

        __u32                      mark;                 /*   172     4 */
        sk_buff_data_t             transport_header;     /*   176     4 */
        sk_buff_data_t             network_header;       /*   180     4 */
        sk_buff_data_t             mac_header;           /*   184     4 */
        sk_buff_data_t             tail;                 /*   188     4 */
        /* --- cacheline 3 boundary (192 bytes) --- */
        sk_buff_data_t             end;                  /*   192     4 */

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

to

        __u32                      mark;                 /*   172     4 */
        __u16                      vlan_tci;             /*   176     2 */

        /* XXX 2 bytes hole, try to pack */

        sk_buff_data_t             transport_header;     /*   180     4 */
        sk_buff_data_t             network_header;       /*   184     4 */

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
2008-07-14 22:49:06 -07:00
committed by David S. Miller
parent 968edbe1c8
commit 6aa895b047
3 changed files with 13 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/skbuff.h
View File

@ -246,6 +246,7 @@ typedef unsigned char *sk_buff_data_t;
* @dma_cookie: a cookie to one of several possible DMA operations
* done by skb DMA functions
* @secmark: security marking
* @vlan_tci: vlan tag control information
*/
struct sk_buff {
@ -326,6 +327,8 @@ struct sk_buff {
__u32 mark;
__u16 vlan_tci;
sk_buff_data_t transport_header;
sk_buff_data_t network_header;
sk_buff_data_t mac_header;