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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-04-20 05:29:13 +0200 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 07:26:28 +0200 |
| commit | 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch) | |
| tree | 5a267e40f9b94014be38dad5de0a52b6628834e0 /net/ipv6/esp6.c | |
| parent | [VLAN] vlan_dev: Use skb_reset_network_header(). (diff) | |
| download | linux-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.xz linux-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.zip | |
[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.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 7fdf84dee73f..b8e8914cc002 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; |