Hi,
On 2/14/25 6:07 PM, Breno Leitao 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)
>
> Given that this patch creates a rawtracepoint, you could hook into it
> using regular tooling, like bpftrace, using regular rawtracepoint
> infrastructure, such as:
>
> rawtracepoint:tcp_cwnd_reduction_tp {
> ....
> }
>
> Signed-off-by: Breno Leitao <[email protected]>
> ---
> ---
> Changes in v2:
> - Close the parenthesis in a new line to honor the tcp.h format (Jakub).
> - Add the bpftrace example in the commit message (Jakub)
> - Link to v1:
> https://lore.kernel.org/r/[email protected]
For future similar situations, note that it's expected to carry-on the
tag already collected in the previous versions, since the delta is only
cosmetic.
No further actions required on your side.
Cheers,
Paolo
