Commit 3d97d88e authored by Yafang Shao's avatar Yafang Shao Committed by David S. Miller
Browse files

tcp: minor optimization around tcp_hdr() usage in receive path 



This is additional to the
commit ea1627c2 ("tcp: minor optimizations around tcp_hdr() usage").
At this point, skb->data is same with tcp_hdr() as tcp header has not
been pulled yet. So use the less expensive one to get the tcp header.

Remove the third parameter of tcp_rcv_established() and put it into
the function body.

Furthermore, the local variables are listed as a reverse christmas tree :)

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0c3a4cf8

include/net/tcp.h

+1 −2
Original line number Diff line number Diff line
@@ -334,8 +334,7 @@ void tcp_write_timer_handler(struct sock *sk); 
void tcp_delack_timer_handler(struct sock *sk);

int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);

int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb);

void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,

			 const struct tcphdr *th);

void tcp_rcv_established(struct sock *sk, struct sk_buff *skb);

void tcp_rcv_space_adjust(struct sock *sk);

int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp);

void tcp_twsk_destructor(struct sock *sk);

include/trace/events/tcp.h

+3 −2
Original line number Diff line number Diff line
@@ -248,8 +248,9 @@ TRACE_EVENT(tcp_probe, 
	),



	TP_fast_assign(

		const struct tcp_sock *tp = tcp_sk(sk);

		const struct tcphdr *th = (const struct tcphdr *)skb->data;

		const struct inet_sock *inet = inet_sk(sk);

		const struct tcp_sock *tp = tcp_sk(sk);



		memset(__entry->saddr, 0, sizeof(struct sockaddr_in6));

		memset(__entry->daddr, 0, sizeof(struct sockaddr_in6));
@@ -261,7 +262,7 @@ TRACE_EVENT(tcp_probe, 
		__entry->dport = ntohs(inet->inet_dport);

		__entry->mark = skb->mark;



		__entry->data_len = skb->len - tcp_hdrlen(skb);

		__entry->data_len = skb->len - __tcp_hdrlen(th);

		__entry->snd_nxt = tp->snd_nxt;

		__entry->snd_una = tp->snd_una;

		__entry->snd_cwnd = tp->snd_cwnd;

net/ipv4/tcp_input.c

+3 −3
Original line number Diff line number Diff line
@@ -5390,11 +5390,11 @@ discard: 
 *	the rest is checked inline. Fast processing is turned on in

 *	tcp_data_queue when everything is OK.

 */

void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,

			 const struct tcphdr *th)

void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)

{

	unsigned int len = skb->len;

	const struct tcphdr *th = (const struct tcphdr *)skb->data;

	struct tcp_sock *tp = tcp_sk(sk);

	unsigned int len = skb->len;



	/* TCP congestion window tracking */

	trace_tcp_probe(sk, skb);

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -1486,7 +1486,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) 
				sk->sk_rx_dst = NULL;

			}

		}

		tcp_rcv_established(sk, skb, tcp_hdr(skb));

		tcp_rcv_established(sk, skb);

		return 0;

	}

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -1322,7 +1322,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 
			}

		}



		tcp_rcv_established(sk, skb, tcp_hdr(skb));

		tcp_rcv_established(sk, skb);

		if (opt_skb)

			goto ipv6_pktoptions;

		return 0;

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