Merge branch 'next' into for-linus

Prepare first round of input updates for 3.20.

1 files changed, 32 insertions, 17 deletions

diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index a9bd8a4828a..6b6002416a7 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -82,12 +82,13 @@ MODULE_PARM_DESC(hystart_ack_delta, "spacing between ack's indicating train (mse
 /* BIC TCP Parameters */
 struct bictcp {
 	u32	cnt;		/* increase cwnd by 1 after ACKs */
-	u32 	last_max_cwnd;	/* last maximum snd_cwnd */
+	u32	last_max_cwnd;	/* last maximum snd_cwnd */
 	u32	loss_cwnd;	/* congestion window at last loss */
 	u32	last_cwnd;	/* the last snd_cwnd */
 	u32	last_time;	/* time when updated last_cwnd */
 	u32	bic_origin_point;/* origin point of bic function */
-	u32	bic_K;		/* time to origin point from the beginning of the current epoch */
+	u32	bic_K;		/* time to origin point
+				   from the beginning of the current epoch */
 	u32	delay_min;	/* min delay (msec << 3) */
 	u32	epoch_start;	/* beginning of an epoch */
 	u32	ack_cnt;	/* number of acks */
@@ -219,7 +220,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 	ca->last_time = tcp_time_stamp;
 
 	if (ca->epoch_start == 0) {
-		ca->epoch_start = tcp_time_stamp;	/* record the beginning of an epoch */
+		ca->epoch_start = tcp_time_stamp;	/* record beginning */
 		ca->ack_cnt = 1;			/* start counting */
 		ca->tcp_cwnd = cwnd;			/* syn with cubic */
 
@@ -263,9 +264,9 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 
 	/* c/rtt * (t-K)^3 */
 	delta = (cube_rtt_scale * offs * offs * offs) >> (10+3*BICTCP_HZ);
-	if (t < ca->bic_K)                                	/* below origin*/
+	if (t < ca->bic_K)                            /* below origin*/
 		bic_target = ca->bic_origin_point - delta;
-	else                                                	/* above origin*/
+	else                                          /* above origin*/
 		bic_target = ca->bic_origin_point + delta;
 
 	/* cubic function - calc bictcp_cnt*/
@@ -285,13 +286,14 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 	/* TCP Friendly */
 	if (tcp_friendliness) {
 		u32 scale = beta_scale;
+
 		delta = (cwnd * scale) >> 3;
 		while (ca->ack_cnt > delta) {		/* update tcp cwnd */
 			ca->ack_cnt -= delta;
 			ca->tcp_cwnd++;
 		}
 
-		if (ca->tcp_cwnd > cwnd){	/* if bic is slower than tcp */
+		if (ca->tcp_cwnd > cwnd) {	/* if bic is slower than tcp */
 			delta = ca->tcp_cwnd - cwnd;
 			max_cnt = cwnd / delta;
 			if (ca->cnt > max_cnt)
@@ -320,7 +322,6 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
 		bictcp_update(ca, tp->snd_cwnd);
 		tcp_cong_avoid_ai(tp, ca->cnt);
 	}
-
 }
 
 static u32 bictcp_recalc_ssthresh(struct sock *sk)
@@ -362,16 +363,28 @@ static void hystart_update(struct sock *sk, u32 delay)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct bictcp *ca = inet_csk_ca(sk);
 
-	if (!(ca->found & hystart_detect)) {
+	if (ca->found & hystart_detect)
+		return;
+
+	if (hystart_detect & HYSTART_ACK_TRAIN) {
 		u32 now = bictcp_clock();
 
 		/* first detection parameter - ack-train detection */
 		if ((s32)(now - ca->last_ack) <= hystart_ack_delta) {
 			ca->last_ack = now;
-			if ((s32)(now - ca->round_start) > ca->delay_min >> 4)
+			if ((s32)(now - ca->round_start) > ca->delay_min >> 4) {
 				ca->found |= HYSTART_ACK_TRAIN;
+				NET_INC_STATS_BH(sock_net(sk),
+						 LINUX_MIB_TCPHYSTARTTRAINDETECT);
+				NET_ADD_STATS_BH(sock_net(sk),
+						 LINUX_MIB_TCPHYSTARTTRAINCWND,
+						 tp->snd_cwnd);
+				tp->snd_ssthresh = tp->snd_cwnd;
+			}
 		}
+	}
 
+	if (hystart_detect & HYSTART_DELAY) {
 		/* obtain the minimum delay of more than sampling packets */
 		if (ca->sample_cnt < HYSTART_MIN_SAMPLES) {
 			if (ca->curr_rtt == 0 || ca->curr_rtt > delay)
@@ -380,15 +393,16 @@ static void hystart_update(struct sock *sk, u32 delay)
 			ca->sample_cnt++;
 		} else {
 			if (ca->curr_rtt > ca->delay_min +
-			    HYSTART_DELAY_THRESH(ca->delay_min>>4))
+			    HYSTART_DELAY_THRESH(ca->delay_min >> 3)) {
 				ca->found |= HYSTART_DELAY;
+				NET_INC_STATS_BH(sock_net(sk),
+						 LINUX_MIB_TCPHYSTARTDELAYDETECT);
+				NET_ADD_STATS_BH(sock_net(sk),
+						 LINUX_MIB_TCPHYSTARTDELAYCWND,
+						 tp->snd_cwnd);
+				tp->snd_ssthresh = tp->snd_cwnd;
+			}
 		}
-		/*
-		 * Either one of two conditions are met,
-		 * we exit from slow start immediately.
-		 */
-		if (ca->found & hystart_detect)
-			tp->snd_ssthresh = tp->snd_cwnd;
 	}
 }
 
@@ -452,7 +466,8 @@ static int __init cubictcp_register(void)
 	 * based on SRTT of 100ms
 	 */
 
-	beta_scale = 8*(BICTCP_BETA_SCALE+beta)/ 3 / (BICTCP_BETA_SCALE - beta);
+	beta_scale = 8*(BICTCP_BETA_SCALE+beta) / 3
+		/ (BICTCP_BETA_SCALE - beta);
 
 	cube_rtt_scale = (bic_scale * 10);	/* 1024*c/rtt */