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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: "Stephen Hemminger" <stephen@networkplumber.org>,
	"Pasi Kärkkäinen" <pasik@iki.fi>,
	netdev@vger.kernel.org
Subject: Re: Linux 3.6.x kernel crash in tcp_slow_start / bictcp_cong_avoid with wfica
Date: Wed, 23 Jan 2013 15:47:11 -0800	[thread overview]
Message-ID: <1358984831.12374.1227.camel@edumazet-glaptop> (raw)
In-Reply-To: <20130123234116.GC16641@order.stressinduktion.org>

On Thu, 2013-01-24 at 00:41 +0100, Hannes Frederic Sowa wrote:
> On Wed, Jan 23, 2013 at 03:26:42PM -0800, Stephen Hemminger wrote:
> > I see no problems when using Citrix.
> > This is a normal strace of the program wifca (in idle loop)
> 
> Thanks, could you also have a look at setsockopts while socket creation and
> connection establishment?

As I said, tp->snd_cwnd is set to 0 by a bug in TCP stack.

Probably a combination of changed sysctls, and a genuine bug.

Please give us /etc/sysctl.conf content.

Adding some BUG_ON(!tp->snd_cwnd) on every writes to tp->snd_cwnd should
catch the bug.

  reply	other threads:[~2013-01-23 23:47 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-23 16:12 Linux 3.6.x kernel crash in tcp_slow_start / bictcp_cong_avoid with wfica Pasi Kärkkäinen
2013-01-23 21:44 ` Hannes Frederic Sowa
2013-01-23 21:51   ` Pasi Kärkkäinen
2013-01-23 22:00     ` Hannes Frederic Sowa
2013-01-24  7:14       ` Pasi Kärkkäinen
2013-01-23 22:25     ` Eric Dumazet
2013-01-23 23:26     ` Stephen Hemminger
2013-01-23 23:41       ` Hannes Frederic Sowa
2013-01-23 23:47         ` Eric Dumazet [this message]
2013-01-24  6:59           ` Pasi Kärkkäinen
2013-01-24 13:51           ` Hannes Frederic Sowa
2013-02-02  3:51             ` Eric Dumazet
2013-02-02 14:28               ` Pasi Kärkkäinen
2013-02-02 15:14                 ` [PATCH] tcp: tcp_process_frto() should not set snd_cwnd to 0 Eric Dumazet
2013-02-02 15:57                   ` Neal Cardwell
2013-02-02 17:32                     ` Eric Dumazet
2013-02-03 19:13                       ` [PATCH] tcp: frto " Eric Dumazet
2013-02-03 21:01                         ` David Miller
2013-02-04 12:14                         ` Ilpo Järvinen
2013-02-04 15:07                           ` Eric Dumazet
2013-02-05 19:44                             ` Eric Dumazet
2013-02-05 19:49                           ` Neal Cardwell
2013-02-06 20:55                             ` David Miller
2013-02-06 21:13                               ` Pasi Kärkkäinen
2013-02-06 21:19                                 ` David Miller
2013-02-06 21:21                                   ` Pasi Kärkkäinen
2013-02-02 15:23                 ` [PATCH] tcp: fix an infinite loop in tcp_slow_start() Eric Dumazet
2013-02-03 21:01                   ` David Miller

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