From 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 19 Apr 2007 20:29:13 -0700 Subject: [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 Signed-off-by: David S. Miller --- net/ipv4/esp4.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/ipv4/esp4.c') diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index de019f9fbfe..5e5613930ff 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; ilen - 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) { -- cgit v1.2.3