Bufferbloat is baaaad, even in our selftests, let's kill it (or at least
reduce it). By doing that, the tests (seem to) have a more stable
transfer, and are then less unstable. But to be tested on CI sharing its
resources!

The last patch is for -next, safer.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Matthieu Baerts (NGI0) (3):
      selftests: mptcp: simult_flows: disable GSO
      selftests: mptcp: simult_flows: adapt limits
      selftests: mptcp: simult_flows: disable 'flaky' mark

 tools/testing/selftests/net/mptcp/simult_flows.sh | 34 ++++++++++++-----------
 1 file changed, 18 insertions(+), 16 deletions(-)
---
base-commit: 1b5f90649a5adc94f765b5dee7fbfec433a5a797
change-id: 20260508-mptcp-sft-sflows-bufferbloat-49122c97440e

Best regards,
--  
Matthieu Baerts (NGI0) <matttbe@kernel.org>

On Fri, 8 May 2026, Matthieu Baerts (NGI0) wrote:

> Bufferbloat is baaaad, even in our selftests, let's kill it (or at least
> reduce it). By doing that, the tests (seem to) have a more stable
> transfer, and are then less unstable. But to be tested on CI sharing its
> resources!
>
> The last patch is for -next, safer.
>
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> ---
> Matthieu Baerts (NGI0) (3):
>      selftests: mptcp: simult_flows: disable GSO
>      selftests: mptcp: simult_flows: adapt limits
>      selftests: mptcp: simult_flows: disable 'flaky' mark
>
> tools/testing/selftests/net/mptcp/simult_flows.sh | 34 ++++++++++++-----------
> 1 file changed, 18 insertions(+), 16 deletions(-)
> ---
> base-commit: 1b5f90649a5adc94f765b5dee7fbfec433a5a797
> change-id: 20260508-mptcp-sft-sflows-bufferbloat-49122c97440e

Hi Matthieu -

Series LGTM, thanks for stabilizing these tests.

Reviewed-by: Mat Martineau <martineau@kernel.org>

Hi Mat,

On 11/05/2026 22:16, Mat Martineau wrote:
> On Fri, 8 May 2026, Matthieu Baerts (NGI0) wrote:
> 
>> Bufferbloat is baaaad, even in our selftests, let's kill it (or at least
>> reduce it). By doing that, the tests (seem to) have a more stable
>> transfer, and are then less unstable. But to be tested on CI sharing its
>> resources!
>>
>> The last patch is for -next, safer.

(...)

> Series LGTM, thanks for stabilizing these tests.
Thank you for the review! Now in our tree:

New patches for t/upstream-net and t/upstream:
- c63cea58b84b: selftests: mptcp: simult_flows: disable GSO
- 4331d54635fb: selftests: mptcp: simult_flows: adapt limits
- Results: d517676f86ac..412c23275fba (export-net)
- Results: c4353991ae52..a3548004f9ed (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/d3218264037efc171c3a4f63b4602cb3407ad024/checks
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/f40e63356649b57b96b78acccc9d42c80220da16/checks

New patches for t/upstream:
- 4845dd70e328: selftests: mptcp: simult_flows: disable 'flaky' mark
- Results: a3548004f9ed..f02cf668b123 (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/bf92df36c693c71c7d20a42c39492c1e3ad7ea03/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/25571380159

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/2bbcbfb2925e
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1091768


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Unstable: 1 failed test(s): packetdrill_dss ⚠️ 
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/25571380159

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/2bbcbfb2925e
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1091768


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Unstable: 1 failed test(s): packetdrill_mp_capable ⚠️ 
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/25571380159

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/2bbcbfb2925e
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1091768


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)