From 745898eaf0eb7a04a56dec1188d9148259510863 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 May 2009 18:50:24 +0000 Subject: tcp: Optimise GRO port comparisons Instead of doing two 16-bit operations for the source/destination ports, we can do one 32-bit operation to take care both. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 7a0f0b27bf1f..ff6adecc54c6 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2544,7 +2544,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) th2 = tcp_hdr(p); - if ((th->source ^ th2->source) | (th->dest ^ th2->dest)) { + if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { NAPI_GRO_CB(p)->same_flow = 0; continue; } -- cgit v1.2.3 From 4a9a2968a17eae42ef5dffca8b37534c864e30cc Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 May 2009 18:50:25 +0000 Subject: tcp: Remove unnecessary window comparisons for GRO The window has already been checked as part of the flag word so there is no need to check it explicitly. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index ff6adecc54c6..313960e4cfdc 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2559,7 +2559,7 @@ found: flush |= flags & TCP_FLAG_CWR; flush |= (flags ^ tcp_flag_word(th2)) & ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH); - flush |= (th->ack_seq ^ th2->ack_seq) | (th->window ^ th2->window); + flush |= th->ack_seq ^ th2->ack_seq; for (i = sizeof(*th); !flush && i < thlen; i += 4) flush |= *(u32 *)((u8 *)th + i) ^ *(u32 *)((u8 *)th2 + i); -- cgit v1.2.3 From 30a3ae30c775e2723f86ef70746ad3cb4404a4c9 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 May 2009 18:50:26 +0000 Subject: tcp: Optimise len/mss comparison Instead of checking len > mss || len == 0, we can accomplish both by checking (len - 1) > mss using the unsigned wraparound. At nearly a million times a second, this might just help. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 313960e4cfdc..68342d431896 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2566,7 +2566,7 @@ found: mss = skb_shinfo(p)->gso_size; - flush |= (len > mss) | !len; + flush |= (len - 1) >= mss; flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); if (flush || skb_gro_receive(head, skb)) { -- cgit v1.2.3 From a5b1cf288d4200506ab62fbb86cc81ace948a306 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 May 2009 18:50:28 +0000 Subject: gro: Avoid unnecessary comparison after skb_gro_header For the overwhelming majority of cases, skb_gro_header's return value cannot be NULL. Yet we must check it because of its current form. This patch splits it up into multiple functions in order to avoid this. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 68342d431896..c3dcec5efea5 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2518,20 +2518,30 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) unsigned int thlen; unsigned int flags; unsigned int mss = 1; + unsigned int hlen; + unsigned int off; int flush = 1; int i; - th = skb_gro_header(skb, sizeof(*th)); - if (unlikely(!th)) - goto out; + off = skb_gro_offset(skb); + hlen = off + sizeof(*th); + th = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, hlen)) { + th = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!th)) + goto out; + } thlen = th->doff * 4; if (thlen < sizeof(*th)) goto out; - th = skb_gro_header(skb, thlen); - if (unlikely(!th)) - goto out; + hlen = off + thlen; + if (skb_gro_header_hard(skb, hlen)) { + th = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!th)) + goto out; + } skb_gro_pull(skb, thlen); -- cgit v1.2.3 From a2a804cddfe65f18f903985e8a8d04c7c9eec354 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 May 2009 18:50:34 +0000 Subject: tcp: Do not check flush when comparing options for GRO There is no need to repeatedly check flush when comparing TCP options for GRO as it will be false 99% of the time where it matters. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c3dcec5efea5..0fb8b441f1f9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2570,7 +2570,7 @@ found: flush |= (flags ^ tcp_flag_word(th2)) & ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH); flush |= th->ack_seq ^ th2->ack_seq; - for (i = sizeof(*th); !flush && i < thlen; i += 4) + for (i = sizeof(*th); i < thlen; i += 4) flush |= *(u32 *)((u8 *)th + i) ^ *(u32 *)((u8 *)th2 + i); -- cgit v1.2.3 From 915219441d566f1da0caa0e262be49b666159e17 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 28 May 2009 21:35:47 -0700 Subject: tcp: Use SKB queue and list helpers instead of doing it by-hand. Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 0fb8b441f1f9..17b89c523f9d 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -439,12 +439,14 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) !tp->urg_data || before(tp->urg_seq, tp->copied_seq) || !before(tp->urg_seq, tp->rcv_nxt)) { + struct sk_buff *skb; + answ = tp->rcv_nxt - tp->copied_seq; /* Subtract 1, if FIN is in queue. */ - if (answ && !skb_queue_empty(&sk->sk_receive_queue)) - answ -= - tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin; + skb = skb_peek_tail(&sk->sk_receive_queue); + if (answ && skb) + answ -= tcp_hdr(skb)->fin; } else answ = tp->urg_seq - tp->copied_seq; release_sock(sk); @@ -1382,11 +1384,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, /* Next get a buffer. */ - skb = skb_peek(&sk->sk_receive_queue); - do { - if (!skb) - break; - + skb_queue_walk(&sk->sk_receive_queue, skb) { /* Now that we have two receive queues this * shouldn't happen. */ @@ -1403,8 +1401,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (tcp_hdr(skb)->fin) goto found_fin_ok; WARN_ON(!(flags & MSG_PEEK)); - skb = skb->next; - } while (skb != (struct sk_buff *)&sk->sk_receive_queue); + } /* Well, if we have backlog, try to process it now yet. */ -- cgit v1.2.3