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| author | Paolo Abeni <pabeni@redhat.com> | 2021-08-14 00:15:45 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-08-14 12:37:25 +0200 |
| commit | ff5a0b421cb23bf6b2898939ffef5b683045d9d3 (patch) | |
| tree | c5601da51b264d08d1ce35d14d7a6b051d6786a5 /Documentation | |
| parent | mptcp: cleanup sysctl data and helpers (diff) | |
| download | linux-ff5a0b421cb23bf6b2898939ffef5b683045d9d3.tar.xz linux-ff5a0b421cb23bf6b2898939ffef5b683045d9d3.zip | |
mptcp: faster active backup recovery
The msk can use backup subflows to transmit in-sequence data
only if there are no other active subflow. On active backup
scenario, the MPTCP connection can do forward progress only
due to MPTCP retransmissions - rtx can pick backup subflows.
This patch introduces a new flag flow MPTCP subflows: if the
underlying TCP connection made no progresses for long time,
and there are other less problematic subflows available, the
given subflow become stale.
Stale subflows are not considered active: if all non backup
subflows become stale, the MPTCP scheduler can pick backup
subflows for plain transmissions.
Stale subflows can return in active state, as soon as any reply
from the peer is observed.
Active backup scenarios can now leverage the available b/w
with no restrinction.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/mptcp-sysctl.rst | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst index 76d939e688b8..b0d4da71e68e 100644 --- a/Documentation/networking/mptcp-sysctl.rst +++ b/Documentation/networking/mptcp-sysctl.rst @@ -45,3 +45,15 @@ allow_join_initial_addr_port - BOOLEAN This is a per-namespace sysctl. Default: 1 + +stale_loss_cnt - INTEGER + The number of MPTCP-level retransmission intervals with no traffic and + pending outstanding data on a given subflow required to declare it stale. + The packet scheduler ignores stale subflows. + A low stale_loss_cnt value allows for fast active-backup switch-over, + an high value maximize links utilization on edge scenarios e.g. lossy + link with high BER or peer pausing the data processing. + + This is a per-namespace sysctl. + + Default: 4 |