[PATCH net-next v2 0/2] mptcp: autotune related improvement

Matthieu Baerts (NGI0)
2026-04-07T08:45:30Z

Here are two patches from Paolo that have been crafted a couple of
months ago, but needed more validation because they were indirectly
causing instabilities in the sefltests. The root cause has been fixed in
'net' recently in commit 8c09412e584d ("selftests: mptcp: more stable
simult_flows tests").

These patches refactor the receive space and RTT estimator, overall
making DRS more correct while avoiding receive buffer drifting to
tcp_rmem[2], which in turn makes the throughput more stable and less
bursty, especially with high bandwidth and low delay environments.

Note that the first patch addresses a very old issue. 'net-next' is
targeted because the change is quite invasive and based on a recent
backlog refactor. The 'Fixes' tag is then there more as a FYI, because
backporting this patch will quickly be blocked due to large conflicts.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changes in v2:
- Patch 1: add missing READ_ONCE() and remove unused entry. (AI)
- Link to v1: https://patch.msgid.link/20260309-net-next-mptcp-reduce-rbuf-v1-0-8f471206f9c5@kernel.org

---
Paolo Abeni (2):
mptcp: better mptcp-level RTT estimator
mptcp: add receive queue awareness in tcp_rcv_space_adjust()

include/trace/events/mptcp.h | 2 +-
net/mptcp/protocol.c | 71 +++++++++++++++++++++++++-------------------
net/mptcp/protocol.h | 37 ++++++++++++++++++++++-
3 files changed, 77 insertions(+), 33 deletions(-)
---
base-commit: c149d90e260ca1b6b9175468955a15c4d95a9f3b
change-id: 20260306-net-next-mptcp-reduce-rbuf-4166ba6fb763

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