Merge branch 'mptcp-receive-path-improvement'

Merge branch 'mptcp-receive-path-improvement'

Matthieu Baerts says:

====================
mptcp: receive path improvement

This series includes several changes to the MPTCP RX path. The main
goals are improving the RX performances, and increase the long term
maintainability.

Some changes reflects recent(ish) improvements introduced in the TCP
stack: patch 1, 2 and 3 are the MPTCP counter part of SKB deferral free
and auto-tuning improvements. Note that patch 3 could possibly fix
additional issues, and overall such patch should protect from similar
issues to arise in the future.

Patches 4-7 are aimed at introducing the socket backlog usage which will
be done in a later series to process the packets received by the
different subflows while the msk socket is owned.

Patch 8 is not related to the RX path, but it contains additional tests
for new features recently introduced in net-next.
====================

Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-0-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>