tcp: use DSACKs that arrive when packets_out is 0
authorNeal Cardwell <ncardwell@google.com>
Wed, 16 Nov 2011 08:58:02 +0000 (08:58 +0000)
committerDavid S. Miller <davem@davemloft.net>
Sun, 27 Nov 2011 23:54:09 +0000 (18:54 -0500)
commit5628adf1a0ff39b9e76e1a8e1c94dadabfd46914
tree99f817c26d6405ea23a7e10e34736e38d199b256
parent7d2b55f80d62b6b4b72d9ef4318a2a49df3e2830
tcp: use DSACKs that arrive when packets_out is 0

The bug: Senders ignored DSACKs after recovery when there were no
outstanding packets (a common scenario for HTTP servers).

The change: when there are no outstanding packets (the "no_queue" goto
label), call tcp_fastretrans_alert() in order to use DSACKs to undo
congestion window reductions.

Other patches in this series will provide other changes that are
necessary to fully fix this problem.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_input.c