In normal use case, the tcp_ca_event would be changed in high frequency.
The developer can monitor the network quality more easier by tracing
TCP stack with this TP event.
So I propose to add a `tcp:tcp_ca_event` trace event
like `tcp:tcp_cong_state_set` to help the people to
trace the TCP connection status
Signed-off-by: Zheao Li <me@xxxxxxxxxxxx>
---
include/net/tcp.h | 9 ++----
include/trace/events/tcp.h | 60 ++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_cong.c | 10 +++++++
3 files changed, 72 insertions(+), 7 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0ca972ebd3dd..a68c5b61889c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1154,13 +1154,8 @@ static inline bool tcp_ca_needs_ecn(const struct sock *sk)
return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN;
}
-static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
-{
- const struct inet_connection_sock *icsk = inet_csk(sk);
-
- if (icsk->icsk_ca_ops->cwnd_event)
- icsk->icsk_ca_ops->cwnd_event(sk, event);
-}
+/* from tcp_cong.c */
+void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event);
/* From tcp_cong.c */
void tcp_set_ca_state(struct sock *sk, const u8 ca_state);
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 7b1ddffa3dfc..993eb00403ea 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -41,6 +41,18 @@
TP_STORE_V4MAPPED(__entry, saddr, daddr)
#endif
+/* The TCP CA event traced by tcp_ca_event*/
+#define tcp_ca_event_names \
+ EM(CA_EVENT_TX_START) \
+ EM(CA_EVENT_CWND_RESTART) \
+ EM(CA_EVENT_COMPLETE_CWR) \
+ EM(CA_EVENT_LOSS) \
+ EM(CA_EVENT_ECN_NO_CE) \
+ EMe(CA_EVENT_ECN_IS_CE)
+
+#define show_tcp_ca_event_names(val) \
+ __print_symbolic(val, tcp_ca_event_names)
+
/*
* tcp event with arguments sk and skb
*
@@ -419,6 +431,54 @@ TRACE_EVENT(tcp_cong_state_set,
__entry->cong_state)
);
+TRACE_EVENT(tcp_ca_event,
+
+ TP_PROTO(struct sock *sk, const u8 ca_event),
+
+ TP_ARGS(sk, ca_event),
+
+ TP_STRUCT__entry(
+ __field(const void *, skaddr)
+ __field(__u16, sport)
+ __field(__u16, dport)
+ __field(__u16, family)
+ __array(__u8, saddr, 4)
+ __array(__u8, daddr, 4)
+ __array(__u8, saddr_v6, 16)
+ __array(__u8, daddr_v6, 16)
+ __field(__u8, ca_event)
+ ),
+
+ TP_fast_assign(
+ struct inet_sock *inet = inet_sk(sk);
+ __be32 *p32;
+
+ __entry->skaddr = sk;
+
+ __entry->sport = ntohs(inet->inet_sport);
+ __entry->dport = ntohs(inet->inet_dport);
+ __entry->family = sk->sk_family;
+
+ p32 = (__be32 *) __entry->saddr;
+ *p32 = inet->inet_saddr;
+
+ p32 = (__be32 *) __entry->daddr;
+ *p32 = inet->inet_daddr;
+
+ TP_STORE_ADDRS(__entry, inet->inet_saddr, inet->inet_daddr,
+ sk->sk_v6_rcv_saddr, sk->sk_v6_daddr);
+
+ __entry->ca_event = ca_event;
+ ),
+
+ TP_printk("family=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c ca_event=%s",
+ show_family_name(__entry->family),
+ __entry->sport, __entry->dport,
+ __entry->saddr, __entry->daddr,
+ __entry->saddr_v6, __entry->daddr_v6,
+ show_tcp_ca_event_names(__entry->ca_event))
+);
+
#endif /* _TRACE_TCP_H */
/* This part must be outside protection */
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 1b34050a7538..fb7ec6ebbbd0 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -34,6 +34,16 @@ struct tcp_congestion_ops *tcp_ca_find(const char *name)
return NULL;
}
+void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
+{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
+
+ trace_tcp_ca_event(sk, (u8)event);
+
+ if (icsk->icsk_ca_ops->cwnd_event)
+ icsk->icsk_ca_ops->cwnd_event(sk, event);
+}
+
void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
{
struct inet_connection_sock *icsk = inet_csk(sk);
--
2.34.1
