tcp: reset timer after any SYNACK retransmit
authorYuchung Cheng <ycheng@google.com>
Mon, 29 Apr 2013 08:44:51 +0000 (08:44 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 29 Apr 2013 19:14:03 +0000 (15:14 -0400)
commitcd75eff64dae8856afbf6ef0f0ca3c145465d8e0
tree2fc9c3079b60e4534935a4daaf6410485a477dd5
parent6a5dc9e598fe90160fee7de098fa319665f5253e
tcp: reset timer after any SYNACK retransmit

Linux immediately returns SYNACK on (spurious) SYN retransmits, but
keeps the SYNACK timer running independently. Thus the timer may
fire right after the SYNACK retransmit and causes a SYN-SYNACK
cross-fire burst.

Adopt the fast retransmit/recovery idea in established state by
re-arming the SYNACK timer after the fast (SYNACK) retransmit. The
timer may fire late up to 500ms due to the current SYNACK timer wheel,
but it's OK to be conservative when network is congested. Eric's new
listener design should address this issue.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_minisocks.c