tcp: do not pass timestamp to tcp_rate_gen()

No longer needed, since tp->tcp_mstamp holds the information.

This is needed to remove sack_state.ack_time in a following patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -1004,7 +1004,7 @@ void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb);
 void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb,
 			    struct rate_sample *rs);
 void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
-		  struct skb_mstamp *now, struct rate_sample *rs);
+		  struct rate_sample *rs);
 void tcp_rate_check_app_limited(struct sock *sk);
 
 /* These functions determine how the current flow behaves in respect of SACK

net/ipv4/tcp_input.c

@@ -3657,8 +3657,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 		tcp_schedule_loss_probe(sk);
 	delivered = tp->delivered - delivered;	/* freshly ACKed or SACKed */
 	lost = tp->lost - lost;			/* freshly marked lost */
-	tcp_rate_gen(sk, delivered, lost, &sack_state.ack_time,
-		     sack_state.rate);
+	tcp_rate_gen(sk, delivered, lost, sack_state.rate);
 	tcp_cong_control(sk, ack, delivered, flag, sack_state.rate);
 	tcp_xmit_recovery(sk, rexmit);
 	return 1;

net/ipv4/tcp_rate.c

@@ -106,7 +106,7 @@ void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb,
 
 /* Update the connection delivery information and generate a rate sample. */
 void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
-		  struct skb_mstamp *now, struct rate_sample *rs)
+		  struct rate_sample *rs)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	u32 snd_us, ack_us;
@@ -120,7 +120,7 @@ void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
 	 * to carry current time, flags, stats like "tcp_sacktag_state".
 	 */
 	if (delivered)
-		tp->delivered_mstamp = *now;
+		tp->delivered_mstamp = tp->tcp_mstamp;
 
 	rs->acked_sacked = delivered;	/* freshly ACKed or SACKed */
 	rs->losses = lost;		/* freshly marked lost */
@@ -138,7 +138,8 @@ void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
 	 * longer phase.
 	 */
 	snd_us = rs->interval_us;				/* send phase */
-	ack_us = skb_mstamp_us_delta(now, &rs->prior_mstamp);	/* ack phase */
+	ack_us = skb_mstamp_us_delta(&tp->tcp_mstamp,
+				     &rs->prior_mstamp); /* ack phase */
 	rs->interval_us = max(snd_us, ack_us);
 
 	/* Normally we expect interval_us >= min-rtt.