gro: Inline skb_gro_header and cache frag0 virtual address

The function skb_gro_header is called four times per packet which
quickly adds up at 10Gb/s.  This patch inlines it to allow better
optimisations.

Some architectures perform multiplication for page_address, which
is done by each skb_gro_header invocation.  This patch caches that
value in skb->cb to avoid the unnecessary multiplications.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu
2009-05-26 18:50:21 +00:00
committed by David S. Miller
parent 42da6994ca
commit 78a478d0ef
2 changed files with 27 additions and 22 deletions

View File

@@ -2390,21 +2390,6 @@ void napi_gro_flush(struct napi_struct *napi)
}
EXPORT_SYMBOL(napi_gro_flush);
void *skb_gro_header(struct sk_buff *skb, unsigned int hlen)
{
unsigned int offset = skb_gro_offset(skb);
hlen += offset;
if (unlikely(skb_headlen(skb) ||
skb_shinfo(skb)->frags[0].size < hlen ||
PageHighMem(skb_shinfo(skb)->frags[0].page)))
return pskb_may_pull(skb, hlen) ? skb->data + offset : NULL;
return page_address(skb_shinfo(skb)->frags[0].page) +
skb_shinfo(skb)->frags[0].page_offset + offset;
}
EXPORT_SYMBOL(skb_gro_header);
int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
struct sk_buff **pp = NULL;
@@ -2520,6 +2505,18 @@ int napi_skb_finish(int ret, struct sk_buff *skb)
}
EXPORT_SYMBOL(napi_skb_finish);
void skb_gro_reset_offset(struct sk_buff *skb)
{
NAPI_GRO_CB(skb)->data_offset = 0;
NAPI_GRO_CB(skb)->frag0 = NULL;
if (!skb_headlen(skb) && !PageHighMem(skb_shinfo(skb)->frags[0].page))
NAPI_GRO_CB(skb)->frag0 =
page_address(skb_shinfo(skb)->frags[0].page) +
skb_shinfo(skb)->frags[0].page_offset;
}
EXPORT_SYMBOL(skb_gro_reset_offset);
int napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
skb_gro_reset_offset(skb);