From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuchung Cheng Subject: [PATCH 2/3 net-next] tcp: refactor CA_Loss state processing Date: Wed, 6 Mar 2013 12:52:09 -0800 Message-ID: <1362603130-16501-2-git-send-email-ycheng@google.com> References: <1362603130-16501-1-git-send-email-ycheng@google.com> Cc: ilpo.jarvinen@cs.helsinki.fi, netdev@vger.kernel.org, Yuchung Cheng To: davem@davemloft.net, ncardwell@google.com, edumazet@google.com, nanditad@google.com Return-path: Received: from mail-ye0-f201.google.com ([209.85.213.201]:61782 "EHLO mail-ye0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551Ab3CFUwV (ORCPT ); Wed, 6 Mar 2013 15:52:21 -0500 Received: by mail-ye0-f201.google.com with SMTP id m12so914126yen.2 for ; Wed, 06 Mar 2013 12:52:21 -0800 (PST) In-Reply-To: <1362603130-16501-1-git-send-email-ycheng@google.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 9933b6b..07a05e0 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2662,6 +2662,30 @@ 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 @@ -2708,12 +2732,6 @@ 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. */ @@ -2744,18 +2762,10 @@ 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