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authorArnaldo Carvalho de Melo <acme@redhat.com>2007-04-19 20:29:13 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-04-25 22:26:28 -0700
commit27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch)
tree5a267e40f9b94014be38dad5de0a52b6628834e0 /net/ipv6/esp6.c
parentbe8bd86321fa7f06359d866ef61fb4d2f3e9dce9 (diff)
downloadlinux-2.6.38-lt-ux500-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.gz
[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>
Diffstat (limited to 'net/ipv6/esp6.c')
-rw-r--r--net/ipv6/esp6.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 7fdf84dee73..b8e8914cc00 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -51,6 +51,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
int clen;
int alen;
int nfrags;
+ u8 *tail;
struct esp_data *esp = x->data;
int hdr_len = (skb_transport_offset(skb) +
sizeof(*esph) + esp->conf.ivlen);
@@ -78,18 +79,19 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
}
/* Fill padding... */
+ tail = skb_tail_pointer(trailer);
do {
int i;
for (i=0; i<clen-skb->len - 2; i++)
- *(u8*)(trailer->tail + i) = i+1;
+ tail[i] = i + 1;
} while (0);
- *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
+ tail[clen-skb->len - 2] = (clen - skb->len) - 2;
pskb_put(skb, trailer, clen - skb->len);
top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
esph = (struct ipv6_esp_hdr *)skb_transport_header(skb);
top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
- *(u8 *)(trailer->tail - 1) = *skb_network_header(skb);
+ *(skb_tail_pointer(skb) - 1) = *skb_network_header(skb);
*skb_network_header(skb) = IPPROTO_ESP;
esph->spi = x->id.spi;