[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/sched/ematch.c b/net/sched/ematch.c
index 959c306..63146d3 100644
--- a/net/sched/ematch.c
+++ b/net/sched/ematch.c
@@ -418,17 +418,19 @@
int tcf_em_tree_dump(struct sk_buff *skb, struct tcf_ematch_tree *tree, int tlv)
{
int i;
- struct rtattr * top_start = (struct rtattr*) skb->tail;
- struct rtattr * list_start;
+ u8 *tail;
+ struct rtattr *top_start = (struct rtattr *)skb_tail_pointer(skb);
+ struct rtattr *list_start;
RTA_PUT(skb, tlv, 0, NULL);
RTA_PUT(skb, TCA_EMATCH_TREE_HDR, sizeof(tree->hdr), &tree->hdr);
- list_start = (struct rtattr *) skb->tail;
+ list_start = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_EMATCH_TREE_LIST, 0, NULL);
+ tail = skb_tail_pointer(skb);
for (i = 0; i < tree->hdr.nmatches; i++) {
- struct rtattr *match_start = (struct rtattr*) skb->tail;
+ struct rtattr *match_start = (struct rtattr *)tail;
struct tcf_ematch *em = tcf_em_get_match(tree, i);
struct tcf_ematch_hdr em_hdr = {
.kind = em->ops ? em->ops->kind : TCF_EM_CONTAINER,
@@ -447,11 +449,12 @@
} else if (em->datalen > 0)
RTA_PUT_NOHDR(skb, em->datalen, (void *) em->data);
- match_start->rta_len = skb->tail - (u8*) match_start;
+ tail = skb_tail_pointer(skb);
+ match_start->rta_len = tail - (u8 *)match_start;
}
- list_start->rta_len = skb->tail - (u8 *) list_start;
- top_start->rta_len = skb->tail - (u8 *) top_start;
+ list_start->rta_len = tail - (u8 *)list_start;
+ top_start->rta_len = tail - (u8 *)top_start;
return 0;
