Re: [PATCH net-next] trace: tcp: Add tracepoint for tcp_cwnd_reduction()

From: Eric Dumazet
Date: Tue Feb 11 2025 - 10:20:16 EST


On Fri, Feb 7, 2025 at 7:04 PM Breno Leitao <leitao@xxxxxxxxxx> wrote:
>
> Add a lightweight tracepoint to monitor TCP congestion window
> adjustments via tcp_cwnd_reduction(). This tracepoint enables tracking
> of:
> - TCP window size fluctuations
> - Active socket behavior
> - Congestion window reduction events
>
> Meta has been using BPF programs to monitor this function for years.
> Adding a proper tracepoint provides a stable API for all users who need
> to monitor TCP congestion window behavior.
>
> Use DECLARE_TRACE instead of TRACE_EVENT to avoid creating trace event
> infrastructure and exporting to tracefs, keeping the implementation
> minimal. (Thanks Steven Rostedt)
>
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> ---

I can give my +2 on this patch, although I have no way of testing it.

I will trust Steven on this :)

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>