Neal Cardwell cdbeb633ca tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
In some situations tcp_send_loss_probe() can realize that it's unable
to send a loss probe (TLP), and falls back to calling tcp_rearm_rto()
to schedule an RTO timer. In such cases, sometimes tcp_rearm_rto()
realizes that the RTO was eligible to fire immediately or at some
point in the past (delta_us <= 0). Previously in such cases
tcp_rearm_rto() was scheduling such "overdue" RTOs to happen at now +
icsk_rto, which caused needless delays of hundreds of milliseconds
(and non-linear behavior that made reproducible testing
difficult). This commit changes the logic to schedule "overdue" RTOs
ASAP, rather than at now + icsk_rto.

Fixes: 6ba8a3b19e76 ("tcp: Tail loss probe (TLP)")
Suggested-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18 16:07:43 -07:00
..
2016-10-20 14:32:22 -04:00
2017-01-13 22:37:16 -05:00
2017-06-15 12:12:40 -04:00
2017-06-15 12:12:40 -04:00
2017-05-21 13:42:36 -04:00
2017-02-15 11:04:11 +01:00
2017-01-10 10:57:12 +01:00
2013-05-31 17:19:05 -07:00