From a5ad24be728d4352b71a81fba471aa41eb71f83a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 8 Feb 2009 18:00:39 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c79087719df0..627be4dc7fb0 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; } -- 2.20.1