diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-04-20 07:29:13 +0400 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 09:26:28 +0400 |
| commit | 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch) | |
| tree | 5a267e40f9b94014be38dad5de0a52b6628834e0 /net/ipv4/esp4.c | |
| parent | be8bd86321fa7f06359d866ef61fb4d2f3e9dce9 (diff) | |
| download | linux-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.xz | |
[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/ipv4/esp4.c')
| -rw-r--r-- | net/ipv4/esp4.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index de019f9fbfe1..5e5613930ffb 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -21,6 +21,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) struct blkcipher_desc desc; struct esp_data *esp; struct sk_buff *trailer; + u8 *tail; int blksize; int clen; int alen; @@ -49,12 +50,13 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) goto error; /* 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); __skb_push(skb, skb->data - skb_network_header(skb)); @@ -62,7 +64,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) esph = (struct ip_esp_hdr *)(skb_network_header(skb) + top_iph->ihl * 4); top_iph->tot_len = htons(skb->len + alen); - *(u8*)(trailer->tail - 1) = top_iph->protocol; + *(skb_tail_pointer(skb) - 1) = top_iph->protocol; /* this is non-NULL only with UDP Encapsulation */ if (x->encap) { |