This series is a follow-up the discussion ongoing here:

https://github.com/multipath-tcp/mptcp_net-next/issues/437

Daire reported several sub-optimal MPTCP behaviour on high-latency
links.

At least 3 different items stands off:

* notsent_lowat setting fooling the scheduler
* sub-optimal send buffer autotuning
* delayed acks being de-facto disabled due to subflow rcvlowat

This series is an attempt to address the first 2 points above.

v3 -> v4:
 - added patch 1/4, fixing a pre-existing issue related. That patch
   shoud likely go via -net, included here because the issue can not
   manifest itself until patch 4/4.
   Despite by best attempt to test this, I thing it would be easier
   to just lest syzkaller crunch it more than a bit.

v2 -> v3:
 - avoid ingremental updates, always recompute sum(ssk->sndbuf) to avoid
   drift on memory pressure/decrease
 - add some needed comments

v1 -> v2:
 - fixed compiler warning in patch 3/3 && more local testing
 

Paolo Abeni (4):
  mptcp: fix delegated action races.
  mptcp: consolidate sockopt synchronization
  mptcp: ignore notsent_lowat setting at the subflow level.
  mptcp: refactor sndbuf auto-tuning.

 net/mptcp/protocol.c | 48 +++++++++++++++---------
 net/mptcp/protocol.h | 89 ++++++++++++++++++++++++++++++--------------
 net/mptcp/sockopt.c  | 28 +++-----------
 net/mptcp/subflow.c  | 27 +++++++-------
 4 files changed, 111 insertions(+), 81 deletions(-)

-- 
2.41.0