From 618d9f25548ba6fc3a9cd2ce5cd56f4f015b0635 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Sat, 20 Sep 2008 21:26:22 -0700 Subject: [PATCH] tcp: back retransmit_high when it over-estimated MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If lost skb is sacked, we might have nothing to retransmit as high as the retransmit_high is pointing to, so place it lower to avoid unnecessary walking. This is mainly for the case where high L'ed skbs gets sacked. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 239cea7b6c0..8f9793a37b6 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2035,16 +2035,22 @@ void tcp_xmit_retransmit_queue(struct sock *sk) struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; struct sk_buff *hole = NULL; + u32 last_lost; int mib_idx; int fwd_rexmitting = 0; if (!tp->lost_out) tp->retransmit_high = tp->snd_una; - if (tp->retransmit_skb_hint) + if (tp->retransmit_skb_hint) { skb = tp->retransmit_skb_hint; - else + last_lost = TCP_SKB_CB(skb)->end_seq; + if (after(last_lost, tp->retransmit_high)) + last_lost = tp->retransmit_high; + } else { skb = tcp_write_queue_head(sk); + last_lost = tp->snd_una; + } /* First pass: retransmit lost packets. */ tcp_for_write_queue_from(skb, sk) { @@ -2073,6 +2079,7 @@ begin_fwd: mib_idx = LINUX_MIB_TCPFORWARDRETRANS; } else if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high)) { + tp->retransmit_high = last_lost; if (!tcp_can_forward_retransmit(sk)) break; /* Backtrack if necessary to non-L'ed skb */ @@ -2089,6 +2096,7 @@ begin_fwd: continue; } else { + last_lost = TCP_SKB_CB(skb)->end_seq; if (icsk->icsk_ca_state != TCP_CA_Loss) mib_idx = LINUX_MIB_TCPFASTRETRANS; else -- 2.41.1