[SK_BUFF]: Convert skb->tail to sk_buff_data_t
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 5eeebd2..9709f94 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -409,15 +409,14 @@
const struct nf_loginfo *li,
const char *prefix, unsigned int plen)
{
- unsigned char *old_tail;
struct nfulnl_msg_packet_hdr pmsg;
struct nlmsghdr *nlh;
struct nfgenmsg *nfmsg;
__be32 tmp_uint;
+ sk_buff_data_t old_tail = inst->skb->tail;
UDEBUG("entered\n");
- old_tail = inst->skb->tail;
nlh = NLMSG_PUT(inst->skb, 0, 0,
NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
sizeof(struct nfgenmsg));