[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/include/net/inet_ecn.h b/include/net/inet_ecn.h
index 06a2c69..de8399a 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -114,14 +114,12 @@
{
switch (skb->protocol) {
case __constant_htons(ETH_P_IP):
- if (skb_network_header(skb) + sizeof(struct iphdr) <=
- skb->tail)
+ if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
return IP_ECN_set_ce(ip_hdr(skb));
break;
case __constant_htons(ETH_P_IPV6):
- if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
- skb->tail)
+ if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
return IP6_ECN_set_ce(ipv6_hdr(skb));
break;
}
diff --git a/include/net/netlink.h b/include/net/netlink.h
index bcaf67b..2c7ab10 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -525,7 +525,7 @@
*/
static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
{
- nlh->nlmsg_len = skb->tail - (unsigned char *) nlh;
+ nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
return skb->len;
}
@@ -538,7 +538,7 @@
*/
static inline void *nlmsg_get_pos(struct sk_buff *skb)
{
- return skb->tail;
+ return skb_tail_pointer(skb);
}
/**
@@ -940,7 +940,7 @@
*/
static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
{
- struct nlattr *start = (struct nlattr *) skb->tail;
+ struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
if (nla_put(skb, attrtype, 0, NULL) < 0)
return NULL;
@@ -960,7 +960,7 @@
*/
static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
{
- start->nla_len = skb->tail - (unsigned char *) start;
+ start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
return skb->len;
}
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index dcb3a91..4129df7 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -337,7 +337,7 @@
static inline int tcf_valid_offset(const struct sk_buff *skb,
const unsigned char *ptr, const int len)
{
- return unlikely((ptr + len) < skb->tail && ptr > skb->head);
+ return unlikely((ptr + len) < skb_tail_pointer(skb) && ptr > skb->head);
}
#ifdef CONFIG_NET_CLS_IND