[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/drivers/net/ibm_emac/ibm_emac_core.c b/drivers/net/ibm_emac/ibm_emac_core.c
index b1ad62d89eb9..3d82d46f4998 100644
--- a/drivers/net/ibm_emac/ibm_emac_core.c
+++ b/drivers/net/ibm_emac/ibm_emac_core.c
@@ -1338,7 +1338,7 @@ static inline int emac_rx_sg_append(struct ocp_enet_private *dev, int slot)
                         dev_kfree_skb(dev->rx_sg_skb);
                         dev->rx_sg_skb = NULL;
                 } else {
-                        cacheable_memcpy(dev->rx_sg_skb->tail,
+                        cacheable_memcpy(skb_tail_pointer(dev->rx_sg_skb),
                                          dev->rx_skb[slot]->data, len);
                         skb_put(dev->rx_sg_skb, len);
                         emac_recycle_rx_skb(dev, slot, len);