diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt
index 671cccf0dcd2..96f50694a748 100644
--- a/Documentation/networking/timestamping.txt
+++ b/Documentation/networking/timestamping.txt
@@ -182,6 +182,16 @@ SOF_TIMESTAMPING_OPT_TSONLY:
   the timestamp even if sysctl net.core.tstamp_allow_data is 0.
   This option disables SOF_TIMESTAMPING_OPT_CMSG.
 
+SOF_TIMESTAMPING_OPT_STATS:
+
+  Optional stats that are obtained along with the transmit timestamps.
+  It must be used together with SOF_TIMESTAMPING_OPT_TSONLY. When the
+  transmit timestamp is available, the stats are available in a
+  separate control message of type SCM_TIMESTAMPING_OPT_STATS, as a
+  list of TLVs (struct nlattr) of types. These stats allow the
+  application to associate various transport layer stats with
+  the transmit timestamps, such as how long a certain block of
+  data was limited by peer's receiver window.
 
 New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to
 disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 9e46d6e656d9..afc901b7a6f6 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -97,4 +97,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h
index afbc98f02d27..81e03530ed39 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -90,5 +90,7 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index 0018fad9039f..57feb0c1f7d7 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -99,4 +99,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 5fe42fc7b6c5..5853f8e92c20 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 2027240aafbb..566ecdcb5b4b 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -108,4 +108,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h
index 5129f23a9ee1..0e12527c4b0e 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 9c935d717df9..7a109b73ddf7 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -89,4 +89,6 @@
 
 #define SO_CNX_ADVICE		0x402E
 
+#define SCM_TIMESTAMPING_OPT_STATS	0x402F
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h
index 1672e3398270..44583a52f882 100644
--- a/arch/powerpc/include/uapi/asm/socket.h
+++ b/arch/powerpc/include/uapi/asm/socket.h
@@ -97,4 +97,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif	/* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index 41b51c2f4f1b..b24a64cbfeb1 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -96,4 +96,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 31aede3af088..a25dc32f5d6a 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -86,6 +86,8 @@
 
 #define SO_CNX_ADVICE		0x0037
 
+#define SCM_TIMESTAMPING_OPT_STATS	0x0038
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION		0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h
index 81435d995e11..9fdbe1fe0473 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -101,4 +101,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 32a7c7e35b71..00e0ee8f001f 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -211,8 +211,11 @@ struct tcp_sock {
 		u8 reord;    /* reordering detected */
 	} rack;
 	u16	advmss;		/* Advertised MSS			*/
-	u8	rate_app_limited:1,  /* rate_{delivered,interval_us} limited? */
-		unused:7;
+	u32	chrono_start;	/* Start time in jiffies of a TCP chrono */
+	u32	chrono_stat[3];	/* Time in jiffies for chrono_stat stats */
+	u8	chrono_type:2,	/* current chronograph type */
+		rate_app_limited:1,  /* rate_{delivered,interval_us} limited? */
+		unused:5;
 	u8	nonagle     : 4,/* Disable Nagle algorithm?             */
 		thin_lto    : 1,/* Use linear timeouts for thin streams */
 		thin_dupack : 1,/* Fast retransmit on first dupack      */
@@ -425,4 +428,6 @@ static inline void tcp_saved_syn_free(struct tcp_sock *tp)
 	tp->saved_syn = NULL;
 }
 
+struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk);
+
 #endif	/* _LINUX_TCP_H */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 7de80739adab..3e097e39d4d2 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1516,11 +1516,26 @@ struct tcp_fastopen_context {
 	struct rcu_head		rcu;
 };
 
+/* Latencies incurred by various limits for a sender. They are
+ * chronograph-like stats that are mutually exclusive.
+ */
+enum tcp_chrono {
+	TCP_CHRONO_UNSPEC,
+	TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */
+	TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */
+	TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */
+	__TCP_CHRONO_MAX,
+};
+
+void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type);
+void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type);
+
 /* write queue abstraction */
 static inline void tcp_write_queue_purge(struct sock *sk)
 {
 	struct sk_buff *skb;
 
+	tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
 	while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
 		sk_wmem_free_skb(sk, skb);
 	sk_mem_reclaim(sk);
@@ -1579,8 +1594,10 @@ static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *
 
 static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
 {
-	if (sk->sk_send_head == skb_unlinked)
+	if (sk->sk_send_head == skb_unlinked) {
 		sk->sk_send_head = NULL;
+		tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
+	}
 	if (tcp_sk(sk)->highest_sack == skb_unlinked)
 		tcp_sk(sk)->highest_sack = NULL;
 }
@@ -1602,6 +1619,7 @@ static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb
 	/* Queue it, remembering where we must start sending. */
 	if (sk->sk_send_head == NULL) {
 		sk->sk_send_head = skb;
+		tcp_chrono_start(sk, TCP_CHRONO_BUSY);
 
 		if (tcp_sk(sk)->highest_sack == NULL)
 			tcp_sk(sk)->highest_sack = skb;
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 67d632f1743d..2c748ddad5f8 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -92,4 +92,6 @@
 
 #define SO_CNX_ADVICE		53
 
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h
index 264e515de16f..464dcca5ed68 100644
--- a/include/uapi/linux/net_tstamp.h
+++ b/include/uapi/linux/net_tstamp.h
@@ -25,8 +25,9 @@ enum {
 	SOF_TIMESTAMPING_TX_ACK = (1<<9),
 	SOF_TIMESTAMPING_OPT_CMSG = (1<<10),
 	SOF_TIMESTAMPING_OPT_TSONLY = (1<<11),
+	SOF_TIMESTAMPING_OPT_STATS = (1<<12),
 
-	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TSONLY,
+	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_STATS,
 	SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
 				 SOF_TIMESTAMPING_LAST
 };
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 73ac0db487f8..c53de2691cec 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -214,6 +214,18 @@ struct tcp_info {
 	__u32	tcpi_data_segs_out;	/* RFC4898 tcpEStatsDataSegsOut */
 
 	__u64   tcpi_delivery_rate;
+
+	__u64	tcpi_busy_time;      /* Time (usec) busy sending data */
+	__u64	tcpi_rwnd_limited;   /* Time (usec) limited by receive window */
+	__u64	tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */
+};
+
+/* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
+enum {
+	TCP_NLA_PAD,
+	TCP_NLA_BUSY,		/* Time (usec) busy sending data */
+	TCP_NLA_RWND_LIMITED,	/* Time (usec) limited by receive window */
+	TCP_NLA_SNDBUF_LIMITED,	/* Time (usec) limited by send buffer */
 };
 
 /* for TCP_MD5SIG socket option */
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d1d1a5a5ad24..ea6fa954c7a0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3839,10 +3839,18 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
 	if (!skb_may_tx_timestamp(sk, tsonly))
 		return;
 
-	if (tsonly)
-		skb = alloc_skb(0, GFP_ATOMIC);
-	else
+	if (tsonly) {
+#ifdef CONFIG_INET
+		if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS) &&
+		    sk->sk_protocol == IPPROTO_TCP &&
+		    sk->sk_type == SOCK_STREAM)
+			skb = tcp_get_timestamping_opt_stats(sk);
+		else
+#endif
+			skb = alloc_skb(0, GFP_ATOMIC);
+	} else {
 		skb = skb_clone(orig_skb, GFP_ATOMIC);
+	}
 	if (!skb)
 		return;
 
diff --git a/net/core/sock.c b/net/core/sock.c
index 14e6145be33b..d8c7f8c877ca 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -854,6 +854,13 @@ set_rcvbuf:
 				sk->sk_tskey = 0;
 			}
 		}
+
+		if (val & SOF_TIMESTAMPING_OPT_STATS &&
+		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
+			ret = -EINVAL;
+			break;
+		}
+
 		sk->sk_tsflags = val;
 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
 			sock_enable_timestamp(sk,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 913f9bbfc030..1149b48700a1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -996,8 +996,11 @@ do_error:
 		goto out;
 out_err:
 	/* make sure we wake any epoll edge trigger waiter */
-	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
+	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
+		     err == -EAGAIN)) {
 		sk->sk_write_space(sk);
+		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
+	}
 	return sk_stream_error(sk, flags, err);
 }
 
@@ -1331,8 +1334,11 @@ do_error:
 out_err:
 	err = sk_stream_error(sk, flags, err);
 	/* make sure we wake any epoll edge trigger waiter */
-	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
+	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
+		     err == -EAGAIN)) {
 		sk->sk_write_space(sk);
+		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
+	}
 	release_sock(sk);
 	return err;
 }
@@ -2702,6 +2708,25 @@ int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
 EXPORT_SYMBOL(compat_tcp_setsockopt);
 #endif
 
+static void tcp_get_info_chrono_stats(const struct tcp_sock *tp,
+				      struct tcp_info *info)
+{
+	u64 stats[__TCP_CHRONO_MAX], total = 0;
+	enum tcp_chrono i;
+
+	for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) {
+		stats[i] = tp->chrono_stat[i - 1];
+		if (i == tp->chrono_type)
+			stats[i] += tcp_time_stamp - tp->chrono_start;
+		stats[i] *= USEC_PER_SEC / HZ;
+		total += stats[i];
+	}
+
+	info->tcpi_busy_time = total;
+	info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED];
+	info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED];
+}
+
 /* Return information about state of tcp endpoint in API format. */
 void tcp_get_info(struct sock *sk, struct tcp_info *info)
 {
@@ -2794,6 +2819,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 	info->tcpi_bytes_acked = tp->bytes_acked;
 	info->tcpi_bytes_received = tp->bytes_received;
 	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
+	tcp_get_info_chrono_stats(tp, info);
 
 	unlock_sock_fast(sk, slow);
 
@@ -2815,6 +2841,26 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);
 
+struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *stats;
+	struct tcp_info info;
+
+	stats = alloc_skb(3 * nla_total_size_64bit(sizeof(u64)), GFP_ATOMIC);
+	if (!stats)
+		return NULL;
+
+	tcp_get_info_chrono_stats(tp, &info);
+	nla_put_u64_64bit(stats, TCP_NLA_BUSY,
+			  info.tcpi_busy_time, TCP_NLA_PAD);
+	nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED,
+			  info.tcpi_rwnd_limited, TCP_NLA_PAD);
+	nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED,
+			  info.tcpi_sndbuf_limited, TCP_NLA_PAD);
+	return stats;
+}
+
 static int do_tcp_getsockopt(struct sock *sk, int level,
 		int optname, char __user *optval, int __user *optlen)
 {
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 22e6a2097ff6..56fe736fd64d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3178,6 +3178,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 			tp->lost_skb_hint = NULL;
 	}
 
+	if (!skb)
+		tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
+
 	if (likely(between(tp->snd_up, prior_snd_una, tp->snd_una)))
 		tp->snd_up = tp->snd_una;
 
@@ -5056,8 +5059,11 @@ static void tcp_check_space(struct sock *sk)
 		/* pairs with tcp_poll() */
 		smp_mb__after_atomic();
 		if (sk->sk_socket &&
-		    test_bit(SOCK_NOSPACE, &sk->sk_socket->flags))
+		    test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
 			tcp_new_space(sk);
+			if (!test_bit(SOCK_NOSPACE, &sk->sk_socket->flags))
+				tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
+		}
 	}
 }
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 19105b46a304..d3545d0cff75 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1514,6 +1514,18 @@ static void tcp_cwnd_validate(struct sock *sk, bool is_cwnd_limited)
 		if (sysctl_tcp_slow_start_after_idle &&
 		    (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
 			tcp_cwnd_application_limited(sk);
+
+		/* The following conditions together indicate the starvation
+		 * is caused by insufficient sender buffer:
+		 * 1) just sent some data (see tcp_write_xmit)
+		 * 2) not cwnd limited (this else condition)
+		 * 3) no more data to send (null tcp_send_head )
+		 * 4) application is hitting buffer limit (SOCK_NOSPACE)
+		 */
+		if (!tcp_send_head(sk) && sk->sk_socket &&
+		    test_bit(SOCK_NOSPACE, &sk->sk_socket->flags) &&
+		    (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
+			tcp_chrono_start(sk, TCP_CHRONO_SNDBUF_LIMITED);
 	}
 }
 
@@ -2081,6 +2093,47 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
 	return false;
 }
 
+static void tcp_chrono_set(struct tcp_sock *tp, const enum tcp_chrono new)
+{
+	const u32 now = tcp_time_stamp;
+
+	if (tp->chrono_type > TCP_CHRONO_UNSPEC)
+		tp->chrono_stat[tp->chrono_type - 1] += now - tp->chrono_start;
+	tp->chrono_start = now;
+	tp->chrono_type = new;
+}
+
+void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* If there are multiple conditions worthy of tracking in a
+	 * chronograph then the highest priority enum takes precedence
+	 * over the other conditions. So that if something "more interesting"
+	 * starts happening, stop the previous chrono and start a new one.
+	 */
+	if (type > tp->chrono_type)
+		tcp_chrono_set(tp, type);
+}
+
+void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+
+	/* There are multiple conditions worthy of tracking in a
+	 * chronograph, so that the highest priority enum takes
+	 * precedence over the other conditions (see tcp_chrono_start).
+	 * If a condition stops, we only stop chrono tracking if
+	 * it's the "most interesting" or current chrono we are
+	 * tracking and starts busy chrono if we have pending data.
+	 */
+	if (tcp_write_queue_empty(sk))
+		tcp_chrono_set(tp, TCP_CHRONO_UNSPEC);
+	else if (type == tp->chrono_type)
+		tcp_chrono_set(tp, TCP_CHRONO_BUSY);
+}
+
 /* This routine writes packets to the network.  It advances the
  * send_head.  This happens as incoming acks open up the remote
  * window for us.
@@ -2103,7 +2156,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 	unsigned int tso_segs, sent_pkts;
 	int cwnd_quota;
 	int result;
-	bool is_cwnd_limited = false;
+	bool is_cwnd_limited = false, is_rwnd_limited = false;
 	u32 max_segs;
 
 	sent_pkts = 0;
@@ -2140,8 +2193,10 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 				break;
 		}
 
-		if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now)))
+		if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) {
+			is_rwnd_limited = true;
 			break;
+		}
 
 		if (tso_segs == 1) {
 			if (unlikely(!tcp_nagle_test(tp, skb, mss_now,
@@ -2186,6 +2241,11 @@ repair:
 			break;
 	}
 
+	if (is_rwnd_limited)
+		tcp_chrono_start(sk, TCP_CHRONO_RWND_LIMITED);
+	else
+		tcp_chrono_stop(sk, TCP_CHRONO_RWND_LIMITED);
+
 	if (likely(sent_pkts)) {
 		if (tcp_in_cwnd_reduction(sk))
 			tp->prr_out += sent_pkts;
@@ -3298,6 +3358,8 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 	fo->copied = space;
 
 	tcp_connect_queue_skb(sk, syn_data);
+	if (syn_data->len)
+		tcp_chrono_start(sk, TCP_CHRONO_BUSY);
 
 	err = tcp_transmit_skb(sk, syn_data, 1, sk->sk_allocation);
 
diff --git a/net/socket.c b/net/socket.c
index e2584c51aa1f..e6318943ad07 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -693,9 +693,14 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 	    ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2))
 		empty = 0;
-	if (!empty)
+	if (!empty) {
 		put_cmsg(msg, SOL_SOCKET,
 			 SCM_TIMESTAMPING, sizeof(tss), &tss);
+
+		if (skb->len && (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS))
+			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
+				 skb->len, skb->data);
+	}
 }
 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);