Re: [PATCH v5 mptcp-next 00/10] mptcp: introduce backlog processing

[Paolo Abeni <pabeni@redhat.com>]

On 10/9/25 3:58 PM, Paolo Abeni wrote:
> @Geliang: if you reproduce the issue multiple times, are there any
> common patterns ? i.e. sender files considerably larger than the client
> one, or only a specific subsets of all the test-cases failing, or ...

Other questions:
- Can you please share your setup details (VM vs baremetal, debug config
vs non debug, vmg vs plain qemu, number of [v]cores...)? I can't repro
the issue locally.
- Can you please share a pcap capture _and_ the selftest text output for
the same failing  test?

In the log shared previously the sender had data queued at the
mptcp-level, but not at TCP-level. In the shared pcap capture the
receiver sends a couple of acks opening the tcp-level and mptcp-level
window, but the sender never replies.

In such scenario the incoming ack should reach ack_update_msk() ->
__mptcp_check_push() -> __mptcp_subflow_push_pending() (or
mptcp_release_cb -> __mptcp_push_pending() ) -> mptcp_sendmsg_frag() but
such chain is apparently broken somewhere in the failing scenario. Could
you please add probe points the the mentioned funtions and perf record
the test, to try to see where the mentioned chain is interrupted?

Thanks,

Paolo