[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/core/gen_stats.c b/net/core/gen_stats.c
index 259473d..bcc2559 100644
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -61,7 +61,7 @@
spin_lock_bh(lock);
d->lock = lock;
if (type)
- d->tail = (struct rtattr *) skb->tail;
+ d->tail = (struct rtattr *)skb_tail_pointer(skb);
d->skb = skb;
d->compat_tc_stats = tc_stats_type;
d->compat_xstats = xstats_type;
@@ -212,7 +212,7 @@
gnet_stats_finish_copy(struct gnet_dump *d)
{
if (d->tail)
- d->tail->rta_len = d->skb->tail - (u8 *) d->tail;
+ d->tail->rta_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
if (d->compat_tc_stats)
if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,