diff options
| author | Breno Leitao <leitao@debian.org> | 2025-04-08 11:32:02 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-10 18:34:05 -0700 |
| commit | 0f08335ade71273f89d19412268b48b55f3e3726 (patch) | |
| tree | 5cd2ae7708d894c5823c0482c67db0be54ea697c | |
| parent | b1e904999542ad6764eafa54545f1c55776006d1 (diff) | |
trace: tcp: Add tracepoint for tcp_sendmsg_locked()
Add a tracepoint to monitor TCP send operations, enabling detailed
visibility into TCP message transmission.
Create a new tracepoint within the tcp_sendmsg_locked function,
capturing traditional fields along with size_goal, which indicates the
optimal data size for a single TCP segment. Additionally, a reference to
the struct sock sk is passed, allowing direct access for BPF programs.
The implementation is largely based on David's patch[1] and suggestions.
Link: https://lore.kernel.org/all/70168c8f-bf52-4279-b4c4-be64527aa1ac@kernel.org/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250408-tcpsendmsg-v3-2-208b87064c28@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/trace/events/tcp.h | 24 | ||||
| -rw-r--r-- | kernel/bpf/btf.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
3 files changed, 27 insertions, 0 deletions
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h index 1a40c41ff8c3..75d3d53a3832 100644 --- a/include/trace/events/tcp.h +++ b/include/trace/events/tcp.h @@ -259,6 +259,30 @@ TRACE_EVENT(tcp_retransmit_synack, __entry->saddr_v6, __entry->daddr_v6) ); +TRACE_EVENT(tcp_sendmsg_locked, + TP_PROTO(const struct sock *sk, const struct msghdr *msg, + const struct sk_buff *skb, int size_goal), + + TP_ARGS(sk, msg, skb, size_goal), + + TP_STRUCT__entry( + __field(const void *, skb_addr) + __field(int, skb_len) + __field(int, msg_left) + __field(int, size_goal) + ), + + TP_fast_assign( + __entry->skb_addr = skb; + __entry->skb_len = skb ? skb->len : 0; + __entry->msg_left = msg_data_left(msg); + __entry->size_goal = size_goal; + ), + + TP_printk("skb_addr %p skb_len %d msg_left %d size_goal %d", + __entry->skb_addr, __entry->skb_len, __entry->msg_left, + __entry->size_goal)); + DECLARE_TRACE(tcp_cwnd_reduction_tp, TP_PROTO(const struct sock *sk, int newly_acked_sacked, int newly_lost, int flag), diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 16ba36f34dfa..24a26b4bb0b8 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6541,6 +6541,7 @@ static const struct bpf_raw_tp_null_args raw_tp_null_args[] = { { "xprt_put_cong", 0x10 }, /* tcp */ { "tcp_send_reset", 0x11 }, + { "tcp_sendmsg_locked", 0x100 }, /* tegra_apb_dma */ { "tegra_dma_tx_status", 0x100 }, /* timer_migration */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 6edc441b3702..e0e96f8fd47c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1160,6 +1160,8 @@ restart: if (skb) copy = size_goal - skb->len; + trace_tcp_sendmsg_locked(sk, msg, skb, size_goal); + if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { bool first_skb; |