| Message ID | e473dfee355991f6f266e9e1e483a5ec552fb683.1695368456.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | f1f975d216146030bfb9b20c7eac4af74f57fe84 |
| Delegated to: | Matthieu Baerts |
| Headers | show |
| Series | mptcp: misc improvement | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 12 lines checked |
| matttbe/build | success | Build and static analysis OK |
| matttbe/KVM_Validation__normal__except_selftest_mptcp_join_ | success | Success! ✅ |
| matttbe/KVM_Validation__debug__except_selftest_mptcp_join_ | warning | Unstable: 1 failed test(s): packetdrill_sockopts |
| matttbe/KVM_Validation__normal__only_selftest_mptcp_join_ | success | Success! ✅ |
| matttbe/KVM_Validation__debug__only_selftest_mptcp_join_ | success | Success! ✅ |
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index f44b364b0055..453d6c78c25c 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -1450,6 +1450,12 @@ void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk) msk_owned_by_me(msk); + /* subflows must ignore any latency-related settings: will not affect + * the user-space - only the msk is relevant - but will foul the + * mptcp scheduler + */ + tcp_sk(ssk)->notsent_lowat = UINT_MAX; + if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { sync_socket_options(msk, ssk);
Any latency related tuning taking action at the subflow level does not really affect the user-space, as only the main MPTCP socket is relevant. Anyway any limiting setting may foul the MPTCP scheduler, not being able to fully use the subflow-level cwin, leading to very poor b/w usage. Enforce notsent_lowat to be a no-op on every subflow. Note that TCP_NOTSENT_LOWAT is currently not supported, and properly dealing with that will require more invasive changes. Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/mptcp/sockopt.c | 6 ++++++ 1 file changed, 6 insertions(+)