diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 32a7c7e35b715debc9c8df324c9393381f2ae900..d5d3bd814338744f0414063e033c769651418451 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      */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 7de80739adabace8c4d6250cb30021c5dace1b9b..e5ff4083870d29a07c99e817fa8041b841e9e91d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1516,6 +1516,20 @@ 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)
 {
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 19105b46a30436ebb85fe97ee43089e77aa028bb..34f751776a0138e1af45d387ca53632a20e3f426 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2081,6 +2081,36 @@ 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);
+
+	tcp_chrono_set(tp, TCP_CHRONO_UNSPEC);
+}
+
 /* This routine writes packets to the network.  It advances the
  * send_head.  This happens as incoming acks open up the remote
  * window for us.