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/ipv6/esp6.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/ipv6/esp6.c') 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; 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); 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; -- cgit v1.2.3