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gro: __napi_gro_receive() optimizations

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compare_ether_header() can have a special implementation on 64 bit
arches if CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is defined.

__napi_gro_receive() and vlan_gro_common() can avoid a conditional
branch to perform device match.

On x86_64, __napi_gro_receive() has now 38 instructions instead of 53

As gcc-4.4.3 still choose to not inline it, add inline keyword to this
performance critical function.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2010-08-26 22:03:08 -07:00
committed by David S. Miller
parent 250ad8f55c
commit 40d0802b3e
3 changed files with 29 additions and 8 deletions
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9
net/8021q/vlan_core.c
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@@ -105,9 +105,12 @@ vlan_gro_common(struct napi_struct *napi, struct vlan_group *grp,
goto drop;
for (p = napi->gro_list; p; p = p->next) {
NAPI_GRO_CB(p)->same_flow =
p->dev == skb->dev && !compare_ether_header(
skb_mac_header(p), skb_gro_mac_header(skb));
unsigned long diffs;
diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
diffs |= compare_ether_header(skb_mac_header(p),
skb_gro_mac_header(skb));
NAPI_GRO_CB(p)->same_flow = !diffs;
NAPI_GRO_CB(p)->flush = 0;
}