[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/act_api.c b/net/sched/act_api.c
index cb21617..28326fb 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -93,7 +93,7 @@
continue;
a->priv = p;
a->order = n_i;
- r = (struct rtattr*) skb->tail;
+ r = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, a->order, 0, NULL);
err = tcf_action_dump_1(skb, a, 0, 0);
if (err < 0) {
@@ -101,7 +101,7 @@
skb_trim(skb, (u8*)r - skb->data);
goto done;
}
- r->rta_len = skb->tail - (u8*)r;
+ r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
n_i++;
if (n_i >= TCA_ACT_MAX_PRIO)
goto done;
@@ -125,7 +125,7 @@
struct rtattr *r ;
int i= 0, n_i = 0;
- r = (struct rtattr*) skb->tail;
+ r = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, a->order, 0, NULL);
RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
for (i = 0; i < (hinfo->hmask + 1); i++) {
@@ -140,7 +140,7 @@
}
}
RTA_PUT(skb, TCA_FCNT, 4, &n_i);
- r->rta_len = skb->tail - (u8*)r;
+ r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
return n_i;
rtattr_failure:
@@ -423,7 +423,7 @@
tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
int err = -EINVAL;
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct rtattr *r;
if (a->ops == NULL || a->ops->dump == NULL)
@@ -432,10 +432,10 @@
RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
if (tcf_action_copy_stats(skb, a, 0))
goto rtattr_failure;
- r = (struct rtattr*) skb->tail;
+ r = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
- r->rta_len = skb->tail - (u8*)r;
+ r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
return err;
}
@@ -449,17 +449,17 @@
{
struct tc_action *a;
int err = -EINVAL;
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct rtattr *r ;
while ((a = act) != NULL) {
- r = (struct rtattr*) skb->tail;
+ r = (struct rtattr *)skb_tail_pointer(skb);
act = a->next;
RTA_PUT(skb, a->order, 0, NULL);
err = tcf_action_dump_1(skb, a, bind, ref);
if (err < 0)
goto errout;
- r->rta_len = skb->tail - (u8*)r;
+ r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
}
return 0;
@@ -635,7 +635,7 @@
{
struct tcamsg *t;
struct nlmsghdr *nlh;
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct rtattr *x;
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
@@ -645,15 +645,15 @@
t->tca__pad1 = 0;
t->tca__pad2 = 0;
- x = (struct rtattr*) skb->tail;
+ x = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
if (tcf_action_dump(skb, a, bind, ref) < 0)
goto rtattr_failure;
- x->rta_len = skb->tail - (u8*)x;
+ x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
- nlh->nlmsg_len = skb->tail - b;
+ nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
rtattr_failure:
@@ -767,7 +767,7 @@
return -ENOBUFS;
}
- b = (unsigned char *)skb->tail;
+ b = skb_tail_pointer(skb);
if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
goto err_out;
@@ -783,16 +783,16 @@
t->tca__pad1 = 0;
t->tca__pad2 = 0;
- x = (struct rtattr *) skb->tail;
+ x = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
if (err < 0)
goto rtattr_failure;
- x->rta_len = skb->tail - (u8 *) x;
+ x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
- nlh->nlmsg_len = skb->tail - b;
+ nlh->nlmsg_len = skb_tail_pointer(skb) - b;
nlh->nlmsg_flags |= NLM_F_ROOT;
module_put(a->ops->owner);
kfree(a);
@@ -884,7 +884,7 @@
if (!skb)
return -ENOBUFS;
- b = (unsigned char *)skb->tail;
+ b = skb_tail_pointer(skb);
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
t = NLMSG_DATA(nlh);
@@ -892,15 +892,15 @@
t->tca__pad1 = 0;
t->tca__pad2 = 0;
- x = (struct rtattr*) skb->tail;
+ x = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
if (tcf_action_dump(skb, a, 0, 0) < 0)
goto rtattr_failure;
- x->rta_len = skb->tail - (u8*)x;
+ x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
- nlh->nlmsg_len = skb->tail - b;
+ nlh->nlmsg_len = skb_tail_pointer(skb) - b;
NETLINK_CB(skb).dst_group = RTNLGRP_TC;
err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
@@ -1015,7 +1015,7 @@
tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
{
struct nlmsghdr *nlh;
- unsigned char *b = skb->tail;
+ unsigned char *b = skb_tail_pointer(skb);
struct rtattr *x;
struct tc_action_ops *a_o;
struct tc_action a;
@@ -1048,7 +1048,7 @@
t->tca__pad1 = 0;
t->tca__pad2 = 0;
- x = (struct rtattr *) skb->tail;
+ x = (struct rtattr *)skb_tail_pointer(skb);
RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
@@ -1056,12 +1056,12 @@
goto rtattr_failure;
if (ret > 0) {
- x->rta_len = skb->tail - (u8 *) x;
+ x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
ret = skb->len;
} else
skb_trim(skb, (u8*)x - skb->data);
- nlh->nlmsg_len = skb->tail - b;
+ nlh->nlmsg_len = skb_tail_pointer(skb) - b;
if (NETLINK_CB(cb->skb).pid && ret)
nlh->nlmsg_flags |= NLM_F_MULTI;
module_put(a_o->owner);