diff mbox

[net-next,v2,1/2] tcp: don't extend RTO on failed loss probe attempts

Message ID 1439403499-24774-2-git-send-email-ycheng@google.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Yuchung Cheng Aug. 12, 2015, 6:18 p.m. UTC 
If TLP was unable to send a probe, it extended the RTO to
now + icsk_rto. But extending the RTO makes little sense
if no TLP probe went out. With this commit, instead of
extending the RTO we re-arm it relative to the transmit time
of the write queue head.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
---
 net/ipv4/tcp_output.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

Comments

Eric Dumazet Aug. 13, 2015, 6:07 p.m. UTC | #1 
On Wed, 2015-08-12 at 11:18 -0700, Yuchung Cheng wrote:
> If TLP was unable to send a probe, it extended the RTO to
> now + icsk_rto. But extending the RTO makes little sense
> if no TLP probe went out. With this commit, instead of
> extending the RTO we re-arm it relative to the transmit time
> of the write queue head.
> 
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
> Signed-off-by: Neal Cardwell <ncardwell@google.com>
> Signed-off-by: Nandita Dukkipati <nanditad@google.com>
> ---

Acked-by: Eric Dumazet <edumazet@google.com>


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diff mbox

Patch

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 7d1efa7..78fc89c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2275,13 +2275,12 @@  void tcp_send_loss_probe(struct sock *sk)
 		tp->tlp_high_seq = tp->snd_nxt;
 
 rearm_timer:
-	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
-				  inet_csk(sk)->icsk_rto,
-				  TCP_RTO_MAX);
-
-	if (likely(!err))
-		NET_INC_STATS_BH(sock_net(sk),
-				 LINUX_MIB_TCPLOSSPROBES);
+	if (likely(!err)) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSSPROBES);
+		/* Reset s.t. tcp_rearm_rto will restart timer from now */
+		inet_csk(sk)->icsk_pending = 0;
+	}
+	tcp_rearm_rto(sk);
 }
 
 /* Push out any pending frames which were held back due to