NIC goes down upon Gnome logout

[Ryan Jacobs]

Hi Skoal,

Thanks very much for this! Very comprehensive! If my post was 
informative, your response we even more-so....

Hummmm, kinda scary to hear that this irqpoll feature is not documented 
as part of 2.6.10 kernel... cuz it appears to be having some effect.

Of course, all I did was change /etc/grub/menu.1st such that the main 
booting option looks like this:

------

title           Ubuntu, kernel 2.6.10-5-386
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.10-5-386 root=/dev/hda1 ro quiet 
splash irqpoll
initrd          /boot/initrd.img-2.6.10-5-386
savedefault
boot

------

Since I did this, I have not been able to duplicate the problem in 2 
days. Of course, this does not mean it's solved (the problem was no at 
all 100% consistent), but so far, everything I did before (that caused 
problems often) has not duplicated the issue.

What was scary was that something so simple (logging out of Gnome) could 
cause an irq conflict... it made me worry that other things could as 
well (we have experienced weird server disconnects over past months in 
the office).

It's also strange that the error message I got advised me to try the 
kernel "irqpoll" option... if it's such a new addition.

And to answer your question... I experience the problem only when 
logging out of the Gnome interface back to the Gnome welcome screen 
(either sitting directly at the server with a monitor, or headless via a 
GNome VNC link)... but it's always a graphical thing... logging in and 
out of text-based sessions (ssh) does not seems to cause any problems...

Ok, I'll keep any eye on this. Thanks very much for the information, 
I've learned a thing or two. It's great to connect with someone who can 
actually target things on a deeper-level (where I have no knowledge 
yet). I imagine that future kernel upgrades would also address this 
problem...

Best,
Ryan



skoal wrote:
>>But my question is this:
> 
> 
> 
> 
>>What is it that I just did??
> 
> 
> 
> 
>>What does irqpoll actually do?, and if it's an integral part is
> 
> 
>>preventing irq conflicts, why is it not active by default? Does it
> 
> take
> 
> 
>>up heaps of resources, or cause other problems that I should be aware
> 
> of?
> 
> 
> 
> Ryan, because of your informative post (and gracious reply) informing
> us of a sol'n, I did a little digging in some source and read some
> kernel mailing list threads...
> 
> 
> 
> Here's what I can try to piece together for ya...
> 
> 
> 
> First, I don't know what kernel version you are using, but that kernel
> boot time option was just a very recent patch to 2.6.12 (and not part
> of a release either, I believe).  I saw no mention of that option in
> the latest 2.6.12 release I'm currently using.  It may be part of the
> 2.6.13 release, but I sure couldn't find any documentation of 'irqpoll'
> in any version prior to 2.6.12.  So, assuming you are using the stock
> 5.04 kernel (2.6.10), I really don't know how this 'irqpoll' option is
> helping you.  It must be a well hidden secret in the code as well...
> 
> 
> 
> With that said, the irqpoll option basically toggles a handler in the
> kernel irq.c (I think) source which basically says, "hey! I just
> received an IRQ request out here on the bus, and I don't know who it's
> from and what I should do with it."  So, the kernel will poll all it's
> IRQ handling routines to find someone to service it.
> 
> 
> 
> Well, a little digging through gdm and gnome-session source, I think
> what's happening is that when you logoff (and since you are doing so
> from a remote SSH, right? or as a local admin with remote access to
> GDM), I think one of your network cards is throwing up an IRQ.  I don't
> know whether it's your ADSL NIC or your intranet NIC doing it though.
> 
> 
> 
> Ok, so what does that mean to you? Well, since you did _not_ experience
> these same problems with warty and only hoary, several things (quite
> possibly) could be causing this.  My first inclination is kernel IRQ
> handler changes.  Next, would be changes in HAL.  HAL is a beast, and I
> really don't understand all the places it sticks it's dirty little
> fingers into.  Anyways, it could even be a more recent NIC driver
> change.  Pure speculation...my specialty!
> 
> 
> 
> Apparently, that 'irqpoll' kernel option fixed it for you, but if it
> persists (or returns at random), the easiest sol'n might just be a $2
> 3Com NIC off eBay.  One of your NIC's could be causing it, and maybe it
> was just ignored somehow in prior (2.6.8?) wary kernel handlers.  I
> dunno.  The only other thing I could think of is if you recently added
> some other piece of hardware on your box when you upgraded to Hoary. 
> Wish I could provide you better information than my pure speculation
> here.  Either way, I found your original post informative and
> intriguing.
> 
> 
> 
> thanks..
> 
> 
> 
> \\//_
> 
>