Commit a2e2a59c authored by David S. Miller's avatar David S. Miller
Browse files

[TCP]: Fix redundant calculations of tcp_current_mss() 



tcp_write_xmit() uses tcp_current_mss(), but some of it's callers,
namely __tcp_push_pending_frames(), already has this value available
already.

While we're here, fix the "cur_mss" argument to be "unsigned int"
instead of plain "unsigned".

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 92df7b51

include/net/tcp.h

+1 −1
Original line number Diff line number Diff line
@@ -850,7 +850,7 @@ extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, 


extern void __tcp_data_snd_check(struct sock *sk, struct sk_buff *skb);

extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,

				      unsigned cur_mss, int nonagle);

				      unsigned int cur_mss, int nonagle);

extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp);

extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);

extern void tcp_xmit_retransmit_queue(struct sock *);

net/ipv4/tcp_output.c

+4 −12
Original line number Diff line number Diff line
@@ -839,11 +839,10 @@ static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp) 
 * Returns 1, if no segments are in flight and we have queued segments, but

 * cannot send anything now because of SWS or another problem.

 */

static int tcp_write_xmit(struct sock *sk, int nonagle)

static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)

{

	struct tcp_sock *tp = tcp_sk(sk);

	struct sk_buff *skb;

	unsigned int mss_now;

	int sent_pkts;



	/* If we are closed, the bytes will have to remain here.
@@ -853,13 +852,6 @@ static int tcp_write_xmit(struct sock *sk, int nonagle) 
	if (unlikely(sk->sk_state == TCP_CLOSE))

		return 0;





	/* Account for SACKS, we may need to fragment due to this.

	 * It is just like the real MSS changing on us midstream.

	 * We also handle things correctly when the user adds some

	 * IP options mid-stream.  Silly to do, but cover it.

	 */

	mss_now = tcp_current_mss(sk, 1);

	sent_pkts = 0;

	while ((skb = sk->sk_send_head) &&

	       tcp_snd_test(sk, skb, mss_now,
@@ -897,7 +889,7 @@ static int tcp_write_xmit(struct sock *sk, int nonagle) 
 * The socket must be locked by the caller.

 */

void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,

			       unsigned cur_mss, int nonagle)

			       unsigned int cur_mss, int nonagle)

{

	struct sk_buff *skb = sk->sk_send_head;
@@ -905,7 +897,7 @@ void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp, 
		if (!tcp_skb_is_last(sk, skb))

			nonagle = TCP_NAGLE_PUSH;

		if (!tcp_snd_test(sk, skb, cur_mss, nonagle) ||

		    tcp_write_xmit(sk, nonagle))

		    tcp_write_xmit(sk, cur_mss, nonagle))

			tcp_check_probe_timer(sk, tp);

	}

}
@@ -916,7 +908,7 @@ void __tcp_data_snd_check(struct sock *sk, struct sk_buff *skb) 


	if (after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd) ||

	    tcp_packets_in_flight(tp) >= tp->snd_cwnd ||

	    tcp_write_xmit(sk, tp->nonagle))

	    tcp_write_xmit(sk, tcp_current_mss(sk, 1), tp->nonagle))

		tcp_check_probe_timer(sk, tp);

}

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