Commit a5ad24be authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller

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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aa4b9f53
......@@ -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;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment