9.1-RC3 IGB dropping connections.

[Barney Cordoba]

--- On Tue, 11/27/12, Zaphod Beeblebrox <zbeeble at gmail.com> wrote:

> From: Zaphod Beeblebrox <zbeeble at gmail.com>
> Subject: Re: 9.1-RC3 IGB dropping connections.
> To: "Andre Oppermann" <andre at freebsd.org>
> Cc: "FreeBSD Hackers" <freebsd-hackers at freebsd.org>, "FreeBSD Stable" <freebsd-stable at freebsd.org>, "FreeBSD Net" <freebsd-net at freebsd.org>
> Date: Tuesday, November 27, 2012, 7:04 PM
> To Jack Vogel's comment, this problem
> only seems to occur on systems
> that are exceedingly lightly loaded (in this case, not yet
> in
> production and I'm the only one using it).
> 
> On Tue, Nov 27, 2012 at 6:21 PM, Andre Oppermann <andre at freebsd.org>
> wrote:
> 
> > r243570 in CURRENT should likely fix this issue. 
> It's only 27 hours old
> > and hasn't been MFC'd yet.
> 
> I'm not sure this addresses what I'm seeing.  It's a
> pause the the
> traffic in the shell that is "fixed" by causing some traffic
> on the
> return channel (watching for the pause --- and then hitting
> enter a
> few times seems to fix it).  I'd expect that TCP
> retransmission should
> take care of this regularly  ... but in this case, it
> doesn't... for
> whatever reason ...

The symptoms point to something having to do with kicking
the start/xmit queue. You might want to check the if_snd queues in
the timer routine.