[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>
This commit is contained in:
Arnaldo Carvalho de Melo
2007-04-19 20:29:13 -07:00
committed by David S. Miller
parent be8bd86321
commit 27a884dc3c
110 changed files with 396 additions and 329 deletions

View File

@@ -2357,7 +2357,7 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
*vlan_encapsulated_proto = htons(ETH_P_IP);
}
skb_set_network_header(skb, skb->tail - skb->data);
skb->network_header = skb->tail;
skb->transport_header = skb->network_header + sizeof(struct iphdr);
skb_put(skb, sizeof(struct iphdr) + sizeof(struct udphdr));
@@ -2696,7 +2696,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
*vlan_encapsulated_proto = htons(ETH_P_IPV6);
}
skb_set_network_header(skb, skb->tail - skb->data);
skb->network_header = skb->tail;
skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
skb_put(skb, sizeof(struct ipv6hdr) + sizeof(struct udphdr));