diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2009-02-08 18:00:39 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-02-08 20:22:19 -0800 |
| commit | a5ad24be728d4352b71a81fba471aa41eb71f83a (patch) | |
| tree | cdba82286ec2ef470fc4ae9531f6ccb14b0f2970 | |
| parent | aa4b9f533ed5a22952e038b9fac2447ccc682124 (diff) | |
gro: Optimise IPv4 packet reception
As this function can be called more than half a million times for
10GbE, it's important to optimise it as much as we can.
This patch does some obvious changes to use 2-byte and 4-byte
operations instead of byte-oriented ones where possible. Bit
ops are also used to replace logical ops to reduce branching.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/af_inet.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c79087719df..627be4dc7fb 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1263,7 +1263,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head, if (!ops || !ops->gro_receive) goto out_unlock; - if (iph->version != 4 || iph->ihl != 5) + if (*(u8 *)iph != 0x45) goto out_unlock; if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) @@ -1281,17 +1281,18 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head, iph2 = ip_hdr(p); - if (iph->protocol != iph2->protocol || - iph->tos != iph2->tos || - memcmp(&iph->saddr, &iph2->saddr, 8)) { + if ((iph->protocol ^ iph2->protocol) | + (iph->tos ^ iph2->tos) | + (iph->saddr ^ iph2->saddr) | + (iph->daddr ^ iph2->daddr)) { NAPI_GRO_CB(p)->same_flow = 0; continue; } /* All fields must match except length and checksum. */ NAPI_GRO_CB(p)->flush |= - memcmp(&iph->frag_off, &iph2->frag_off, 4) || - (u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) != id; + (iph->ttl ^ iph2->ttl) | + ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id); NAPI_GRO_CB(p)->flush |= flush; } |