From: Yuchung Cheng <ycheng@google.com>
To: davem@davemloft.net, ncardwell@google.com, edumazet@google.com,
nanditad@google.com
Cc: ilpo.jarvinen@cs.helsinki.fi, netdev@vger.kernel.org,
Yuchung Cheng <ycheng@google.com>
Subject: [PATCH v2 2/3 net-next] tcp: refactor CA_Loss state processing
Date: Wed, 20 Mar 2013 16:32:59 -0700 [thread overview]
Message-ID: <1363822380-16687-2-git-send-email-ycheng@google.com> (raw)
In-Reply-To: <1363822380-16687-1-git-send-email-ycheng@google.com>
Consolidate all of TCP CA_Loss state processing in
tcp_fastretrans_alert() into a new function called tcp_process_loss().
This is to prepare the new F-RTO implementation in the next patch.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
---
net/ipv4/tcp_input.c | 42 ++++++++++++++++++++++++++----------------
1 file changed, 26 insertions(+), 16 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 231c79f..8d821e4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2664,6 +2664,30 @@ static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
tcp_set_ca_state(sk, TCP_CA_Recovery);
}
+/* Process an ACK in CA_Loss state. Move to CA_Open if lost data are
+ * recovered or spurious. Otherwise retransmits more on partial ACKs.
+ */
+static void tcp_process_loss(struct sock *sk, int flag)
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!before(tp->snd_una, tp->high_seq)) {
+ icsk->icsk_retransmits = 0;
+ tcp_try_undo_recovery(sk);
+ return;
+ }
+
+ if (flag & FLAG_DATA_ACKED)
+ icsk->icsk_retransmits = 0;
+ if (tcp_is_reno(tp) && flag & FLAG_SND_UNA_ADVANCED)
+ tcp_reset_reno_sack(tp);
+ if (tcp_try_undo_loss(sk))
+ return;
+ tcp_moderate_cwnd(tp);
+ tcp_xmit_retransmit_queue(sk);
+}
+
/* Process an event, which can update packets-in-flight not trivially.
* Main goal of this function is to calculate new estimate for left_out,
* taking into account both packets sitting in receiver's buffer and
@@ -2710,12 +2734,6 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
tp->retrans_stamp = 0;
} else if (!before(tp->snd_una, tp->high_seq)) {
switch (icsk->icsk_ca_state) {
- case TCP_CA_Loss:
- icsk->icsk_retransmits = 0;
- if (tcp_try_undo_recovery(sk))
- return;
- break;
-
case TCP_CA_CWR:
/* CWR is to be held something *above* high_seq
* is ACKed for CWR bit to reach receiver. */
@@ -2746,18 +2764,10 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
newly_acked_sacked = pkts_acked + tp->sacked_out - prior_sacked;
break;
case TCP_CA_Loss:
- if (flag & FLAG_DATA_ACKED)
- icsk->icsk_retransmits = 0;
- if (tcp_is_reno(tp) && flag & FLAG_SND_UNA_ADVANCED)
- tcp_reset_reno_sack(tp);
- if (!tcp_try_undo_loss(sk)) {
- tcp_moderate_cwnd(tp);
- tcp_xmit_retransmit_queue(sk);
- return;
- }
+ tcp_process_loss(sk, flag);
if (icsk->icsk_ca_state != TCP_CA_Open)
return;
- /* Loss is undone; fall through to processing in Open state. */
+ /* Fall through to processing in Open state. */
default:
if (tcp_is_reno(tp)) {
if (flag & FLAG_SND_UNA_ADVANCED)
--
1.8.1.3
next prev parent reply other threads:[~2013-03-20 23:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-20 23:32 [PATCH v2 1/3 net-next] tcp: refactor F-RTO Yuchung Cheng
2013-03-20 23:32 ` Yuchung Cheng [this message]
2013-03-20 23:56 ` [PATCH v2 2/3 net-next] tcp: refactor CA_Loss state processing Eric Dumazet
2013-03-20 23:33 ` [PATCH v2 3/3 net-next] tcp: implement RFC5682 F-RTO Yuchung Cheng
2013-03-21 5:00 ` Eric Dumazet
2013-03-21 13:26 ` Neal Cardwell
2013-03-20 23:55 ` [PATCH v2 1/3 net-next] tcp: refactor F-RTO Eric Dumazet
2013-03-21 15:48 ` David Miller
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