From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH v2 1/1] tcp: fixing TLP's FIN recovery Date: Thu, 12 Jun 2014 08:28:36 -0700 Message-ID: <1402586916.3645.485.camel@edumazet-glaptop2.roam.corp.google.com> References: <1402583577.3645.477.camel@edumazet-glaptop2.roam.corp.google.com> <1402585712-12103-1-git-send-email-per.hurtig@kau.se> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: panweiping3@gmail.com, nanditad@google.com, netdev@vger.kernel.org, anna.brunstrom@kau.se, mohammad.rajiullah@kau.se, ncardwell@google.com, sergei.shtylyov@cogentembedded.com To: Per Hurtig Return-path: Received: from mail-pa0-f41.google.com ([209.85.220.41]:38072 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756083AbaFLP2l (ORCPT ); Thu, 12 Jun 2014 11:28:41 -0400 Received: by mail-pa0-f41.google.com with SMTP id kq14so1134355pab.0 for ; Thu, 12 Jun 2014 08:28:40 -0700 (PDT) In-Reply-To: <1402585712-12103-1-git-send-email-per.hurtig@kau.se> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2014-06-12 at 17:08 +0200, Per Hurtig wrote: > Fix to a problem observed when losing a FIN segment that does not > contain data. In such situations, TLP is unable to recover from > *any* tail loss and instead adds at least PTO ms to the > retransmission process, i.e., RTO = RTO + PTO. > > Signed-off-by: Per Hurtig > --- > net/ipv4/tcp_output.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index ad7549f..819bf0c 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -2131,9 +2131,7 @@ void tcp_send_loss_probe(struct sock *sk) > if (WARN_ON(!skb || !tcp_skb_pcount(skb))) > goto rearm_timer; > > - /* Probe with zero data doesn't trigger fast recovery. */ > - if (skb->len > 0) > - err = __tcp_retransmit_skb(sk, skb); > + err = __tcp_retransmit_skb(sk, skb); > > /* Record snd_nxt for loss detection. */ > if (likely(!err)) Thanks a lot Per Signed-off-by: Eric Dumazet