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Date: Fri, 06 Jun 2014 12:07:08 -0700
From: Eric Dumazet <eric.dumazet@...il.com>
To: Per Hurtig <per.hurtig@....se>
Cc: netdev@...r.kernel.org, anna.brunstrom@....se,
mohammad.rajiullah@....se, Neal Cardwell <ncardwell@...gle.com>,
Nandita Dukkipati <nanditad@...gle.com>
Subject: Re: tcp: fixing TLP's FIN recovery
On Fri, 2014-06-06 at 20:46 +0200, Per Hurtig wrote:
> From ab1b16ef8aba4300b1a6e965c3ab7d0cb269bb2a Mon Sep 17 00:00:00 2001
> From: Per Hurtig <per.hurtig@....se>
> Date: Fri, 6 Jun 2014 18:36:19 +0200
> Subject: [PATCH 1/1] tcp: fixing TLP's FIN recovery
>
> 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 <per.hurtig@....se>
> ---
> net/ipv4/tcp_output.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
> index d463c35..2c29926 100644
> --- a/net/ipv4/tcp_output.c
> +++ b/net/ipv4/tcp_output.c
> @@ -2130,8 +2130,9 @@ 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)
> + /* Probe with zero data doesn't trigger fast
> recovery, unless
> + * FIN flag is set. */
> + if ((skb->len > 0) ||
> (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
> err = __tcp_retransmit_skb(sk, skb);
>
> /* Record snd_nxt for loss detection. */
> --
> 1.9.1
>
Patch was mangled. Please fix and resend.
Please CC Nandita & Neal,
Thanks
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