[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, 2 insertions, 2 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 46ebf141ee5a..600d3ff347fc 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -2195,7 +2195,7 @@ static int fill_rxd_3buf(struct s2io_nic *nic, struct RxD_t *rxdp, struct \
         frag_list->next = NULL;
         tmp = (void *)ALIGN((long)frag_list->data, ALIGN_SIZE + 1);
         frag_list->data = tmp;
-        frag_list->tail = tmp;
+        skb_reset_tail_pointer(frag_list);
 
         /* Buffer-2 receives L4 data payload */
         ((struct RxD3*)rxdp)->Buffer2_ptr = pci_map_single(nic->pdev,
@@ -2349,7 +2349,7 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
                         tmp += ALIGN_SIZE;
                         tmp &= ~ALIGN_SIZE;
                         skb->data = (void *) (unsigned long)tmp;
-                        skb->tail = (void *) (unsigned long)tmp;
+                        skb_reset_tail_pointer(skb);
 
                         if (!(((struct RxD3*)rxdp)->Buffer0_ptr))
                                 ((struct RxD3*)rxdp)->Buffer0_ptr =