Re: [PATCH mptcp-net v2 0/6] selftests: mptcp: join: fix flaky tests

[Geliang Tang <geliang@kernel.org>]

On Wed, 2025-11-05 at 10:00 +0800, Geliang Tang wrote:
> Hi Matt,
> 
> On Tue, 2025-11-04 at 13:10 +0100, Matthieu Baerts wrote:
> > Hi Geliang,
> > 
> > On 02/11/2025 12:30, Matthieu Baerts (NGI0) wrote:
> > > When looking at the recent CI results on NIPA and MPTCP CIs, a
> > > few
> > > MPTCP
> > > Join tests are marked as unstable. Here are some fixes for that.
> > > 
> > > - Patch 1: a small fix for mptcp_connect.sh, printing a note as
> > >   initially intended. For >=v5.13.
> > > 
> > > - Patch 2: avoid unexpected reset when closing subflows. For >=
> > > 5.13.
> > > 
> > > - Patches 3-4: longer transfer when not waiting for the end. For
> > > > =5.18.
> > > 
> > > - Patch 5: drop noisy plain RST packets when looking for
> > > MP_FASTCLOSE.
> > >   For >= 5.18.
> > > 
> > > - Patch 6: read all received data when expecting a reset. For >=
> > > v6.1.
> > > 
> > > When reviewing patches 2-6, please double check that I'm not
> > > hiding
> > > real
> > > issues by tweaking the tests suite.
> > 
> > (More eyes are welcome, especially on patch 5/6!)
> 
> I tested patch 5/6 again and found that only dropping the plain RST
> from ns1 is sufficient to make it work. There is no need to

Oops, the test of only dropping ns1's plain RST failed after dozens of
loops.

> simultaneously drop the plain RST from ns2. What do you think?

So we do need to drop both ns1's and ns2's plain RST simultaneously, as
done in patch 5/6.

Thanks,
-Geliang

> 
> If you agree, I can send a squash-to patch to fix it.
> 
> Thanks,
> -Geliang
> 
> > 
> > Thank you for the review! Now in our tree:
> > 
> > New patches for t/upstream-net and t/upstream:
> > - a9a49f5a022a: selftests: mptcp: connect: fix fallback note due to
> > OoO
> > - 818251a0fc51: selftests: mptcp: join: rm: set backup flag
> > - f0864a03b80b: selftests: mptcp: join: endpoints: longer transfer
> > - a68bf9260dab: selftests: mptcp: join: userspace: longer transfer
> > - 69569761c0f6: selftests: mptcp: join: fastclose: drop plain RST
> > - e99b7db5862e: selftests: mptcp: connect: trunc: read all recv
> > data
> > - Results: 3cf18f92ab22..09c25f9f5ca3 (export-net)
> > - Results: b35f4b01c8d3..625ded86ead5 (export)
> > 
> > Tests are now in progress:
> > 
> > - export-net:
> > https://github.com/multipath-tcp/mptcp_net-next/commit/c8f9b6716c62042010e0e231a789467236c55625/checks
> > - export:
> > https://github.com/multipath-tcp/mptcp_net-next/commit/31b5d615cdeb4fd6ea58fcd577b48543dd3b0617/checks
> > 
> > Cheers,
> > Matt
> 
>