[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>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index dcb3a91f1364..4129df708079 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -337,7 +337,7 @@ static inline unsigned char * tcf_get_base_ptr(struct sk_buff *skb, int layer)
 static inline int tcf_valid_offset(const struct sk_buff *skb,
                                    const unsigned char *ptr, const int len)
 {
-        return unlikely((ptr + len) < skb->tail && ptr > skb->head);
+        return unlikely((ptr + len) < skb_tail_pointer(skb) && ptr > skb->head);
 }
 
 #ifdef CONFIG_NET_CLS_IND