Re: [PATCH] tracepoint: add new `tcp:tcp_ca_event_set` trace event
From: Neal Cardwell <ncardwell@google.com>
Date: 2023-08-07 20:00:41
Also in:
bpf, linux-trace-kernel, lkml
On Mon, Aug 7, 2023 at 2:33 PM Manjusaka [off-list ref] wrote:
quoted hunk ↗ jump to hunk
In normal use case, the tcp_ca_event would be changed in high frequency. It's a good indicator to represent the network quanlity. So I propose to add a `tcp:tcp_ca_event_set` trace event like `tcp:tcp_cong_state_set` to help the people to trace the TCP connection status Signed-off-by: Manjusaka <redacted> --- include/net/tcp.h | 9 ++------ include/trace/events/tcp.h | 45 ++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_cong.c | 10 +++++++++ 3 files changed, 57 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 bf06db8d2046..38415c5f1d52 100644 --- a/include/trace/events/tcp.h +++ b/include/trace/events/tcp.h@@ -416,6 +416,51 @@ TRACE_EVENT(tcp_cong_state_set, __entry->cong_state) ); +TRACE_EVENT(tcp_ca_event_set,
Regarding the proposed name, "tcp_ca_event_set"... including "set" in the name is confusing, since the tcp_ca_event() function is not really setting anything. :-) The trace_tcp_cong_state_set() call you are using as a model has "set" in the name because the function it is tracing, tcp_set_ca_state(), has "set" in the name. :-) Would it work to use something like: TRACE_EVENT(tcp_ca_event, thanks, neal