[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/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 5197b6c..80e6f81 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1363,7 +1363,7 @@
struct tcmsg *tcm)
{
struct hfsc_class *cl = (struct hfsc_class *)arg;
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct rtattr *rta = (struct rtattr *)b;
tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->classid : TC_H_ROOT;
@@ -1374,7 +1374,7 @@
RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
if (hfsc_dump_curves(skb, cl) < 0)
goto rtattr_failure;
- rta->rta_len = skb->tail - b;
+ rta->rta_len = skb_tail_pointer(skb) - b;
return skb->len;
rtattr_failure:
@@ -1576,7 +1576,7 @@
hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
{
struct hfsc_sched *q = qdisc_priv(sch);
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct tc_hfsc_qopt qopt;
qopt.defcls = q->defcls;