[TCP]: remove unused argument to cong_avoid op

None of the existing TCP congestion controls use the rtt value pased
in the ca_ops->cong_avoid interface.  Which is lucky because seq_rtt
could have been -1 when handling a duplicate ack.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -652,8 +652,7 @@ struct tcp_congestion_ops {
 	/* lower bound for congestion window (optional) */
 	u32 (*min_cwnd)(const struct sock *sk);
 	/* do new cwnd calculation (required) */
-	void (*cong_avoid)(struct sock *sk, u32 ack,
-			   u32 rtt, u32 in_flight, int good_ack);
+	void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight, int good_ack);
 	/* call before changing ca_state (optional) */
 	void (*set_state)(struct sock *sk, u8 new_state);
 	/* call when cwnd event occurs (optional) */
@@ -684,8 +683,7 @@ extern void tcp_slow_start(struct tcp_sock *tp);
 
 extern struct tcp_congestion_ops tcp_init_congestion_ops;
 extern u32 tcp_reno_ssthresh(struct sock *sk);
-extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack,
-				u32 rtt, u32 in_flight, int flag);
+extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight, int flag);
 extern u32 tcp_reno_min_cwnd(const struct sock *sk);
 extern struct tcp_congestion_ops tcp_reno;
 

net/ipv4/tcp_bic.c

@@ -137,7 +137,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 }
 
 static void bictcp_cong_avoid(struct sock *sk, u32 ack,
-			      u32 seq_rtt, u32 in_flight, int data_acked)
+			      u32 in_flight, int data_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct bictcp *ca = inet_csk_ca(sk);

net/ipv4/tcp_cong.c

@@ -324,8 +324,7 @@ EXPORT_SYMBOL_GPL(tcp_slow_start);
 /* This is Jacobson's slow start and congestion avoidance.
  * SIGCOMM '88, p. 328.
  */
-void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 rtt, u32 in_flight,
-			 int flag)
+void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 

net/ipv4/tcp_cubic.c

@@ -270,7 +270,7 @@ static inline void measure_delay(struct sock *sk)
 }
 
 static void bictcp_cong_avoid(struct sock *sk, u32 ack,
-			      u32 seq_rtt, u32 in_flight, int data_acked)
+			      u32 in_flight, int data_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct bictcp *ca = inet_csk_ca(sk);

net/ipv4/tcp_highspeed.c

@@ -109,7 +109,7 @@ static void hstcp_init(struct sock *sk)
 	tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
 }
 
-static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
+static void hstcp_cong_avoid(struct sock *sk, u32 adk,
 			     u32 in_flight, int data_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);

net/ipv4/tcp_htcp.c

@@ -225,7 +225,7 @@ static u32 htcp_recalc_ssthresh(struct sock *sk)
 	return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
 }
 
-static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void htcp_cong_avoid(struct sock *sk, u32 ack, s32 rtt,
 			    u32 in_flight, int data_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);

net/ipv4/tcp_hybla.c

@@ -85,7 +85,7 @@ static inline u32 hybla_fraction(u32 odds)
  *     o Give cwnd a new value based on the model proposed
  *     o remember increments <1
  */
-static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void hybla_cong_avoid(struct sock *sk, u32 ack,
 			    u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -103,7 +103,7 @@ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
 		return;
 
 	if (!ca->hybla_en)
-		return tcp_reno_cong_avoid(sk, ack, rtt, in_flight, flag);
+		return tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 
 	if (ca->rho == 0)
 		hybla_recalc_param(sk);

net/ipv4/tcp_illinois.c

@@ -258,7 +258,7 @@ static void tcp_illinois_state(struct sock *sk, u8 new_state)
 /*
  * Increase window in response to successful acknowledgment.
  */
-static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack,
 				    u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);

net/ipv4/tcp_input.c

@@ -2323,11 +2323,11 @@ static inline void tcp_ack_update_rtt(struct sock *sk, const int flag,
 		tcp_ack_no_tstamp(sk, seq_rtt, flag);
 }
 
-static void tcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void tcp_cong_avoid(struct sock *sk, u32 ack,
 			   u32 in_flight, int good)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
-	icsk->icsk_ca_ops->cong_avoid(sk, ack, rtt, in_flight, good);
+	icsk->icsk_ca_ops->cong_avoid(sk, ack, in_flight, good);
 	tcp_sk(sk)->snd_cwnd_stamp = tcp_time_stamp;
 }
 
@@ -2826,11 +2826,11 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
 		/* Advance CWND, if state allows this. */
 		if ((flag & FLAG_DATA_ACKED) && !frto_cwnd &&
 		    tcp_may_raise_cwnd(sk, flag))
-			tcp_cong_avoid(sk, ack,  seq_rtt, prior_in_flight, 0);
+			tcp_cong_avoid(sk, ack, prior_in_flight, 0);
 		tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag);
 	} else {
 		if ((flag & FLAG_DATA_ACKED) && !frto_cwnd)
-			tcp_cong_avoid(sk, ack, seq_rtt, prior_in_flight, 1);
+			tcp_cong_avoid(sk, ack, prior_in_flight, 1);
 	}
 
 	if ((flag & FLAG_FORWARD_PROGRESS) || !(flag&FLAG_NOT_DUP))

net/ipv4/tcp_lp.c

@@ -115,13 +115,12 @@ static void tcp_lp_init(struct sock *sk)
  * Will only call newReno CA when away from inference.
  * From TCP-LP's paper, this will be handled in additive increasement.
  */
-static void tcp_lp_cong_avoid(struct sock *sk, u32 ack, u32 rtt, u32 in_flight,
-			      int flag)
+static void tcp_lp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight, int flag)
 {
 	struct lp *lp = inet_csk_ca(sk);
 
 	if (!(lp->flag & LP_WITHIN_INF))
-		tcp_reno_cong_avoid(sk, ack, rtt, in_flight, flag);
+		tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 }
 
 /**

net/ipv4/tcp_scalable.c

@@ -15,7 +15,7 @@
 #define TCP_SCALABLE_AI_CNT	50U
 #define TCP_SCALABLE_MD_SCALE	3
 
-static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack,
 				    u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);

net/ipv4/tcp_vegas.c

@@ -163,13 +163,13 @@ void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event)
 EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event);
 
 static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
-				 u32 seq_rtt, u32 in_flight, int flag)
+				 u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct vegas *vegas = inet_csk_ca(sk);
 
 	if (!vegas->doing_vegas_now)
-		return tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+		return tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 
 	/* The key players are v_beg_snd_una and v_beg_snd_nxt.
 	 *
@@ -228,7 +228,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
 			/* We don't have enough RTT samples to do the Vegas
 			 * calculation, so we'll behave like Reno.
 			 */
-			tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+			tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 		} else {
 			u32 rtt, target_cwnd, diff;
 

net/ipv4/tcp_veno.c

@@ -115,13 +115,13 @@ static void tcp_veno_cwnd_event(struct sock *sk, enum tcp_ca_event event)
 }
 
 static void tcp_veno_cong_avoid(struct sock *sk, u32 ack,
-				u32 seq_rtt, u32 in_flight, int flag)
+				u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct veno *veno = inet_csk_ca(sk);
 
 	if (!veno->doing_veno_now)
-		return tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+		return tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 
 	/* limited by applications */
 	if (!tcp_is_cwnd_limited(sk, in_flight))
@@ -132,7 +132,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack,
 		/* We don't have enough rtt samples to do the Veno
 		 * calculation, so we'll behave like Reno.
 		 */
-		tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+		tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 	} else {
 		u32 rtt, target_cwnd;
 

net/ipv4/tcp_yeah.c

@@ -70,7 +70,7 @@ static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked, ktime_t last)
 }
 
 static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack,
-				u32 seq_rtt, u32 in_flight, int flag)
+				u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct yeah *yeah = inet_csk_ca(sk);