[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/drivers/net/wan/lmc/lmc_main.c b/drivers/net/wan/lmc/lmc_main.c
index d485146..b731f3a 100644
--- a/drivers/net/wan/lmc/lmc_main.c
+++ b/drivers/net/wan/lmc/lmc_main.c
@@ -1636,7 +1636,7 @@
if (nsb) {
sc->lmc_rxq[i] = nsb;
nsb->dev = dev;
- sc->lmc_rxring[i].buffer1 = virt_to_bus (nsb->tail);
+ sc->lmc_rxring[i].buffer1 = virt_to_bus(skb_tail_pointer(nsb));
}
sc->failed_recv_alloc = 1;
goto skip_packet;
@@ -1679,7 +1679,7 @@
if (nsb) {
sc->lmc_rxq[i] = nsb;
nsb->dev = dev;
- sc->lmc_rxring[i].buffer1 = virt_to_bus (nsb->tail);
+ sc->lmc_rxring[i].buffer1 = virt_to_bus(skb_tail_pointer(nsb));
/* Transferred to 21140 below */
}
else {