NIC goes down upon Gnome logout

[skoal]

> 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..



\\//_


-- 
skoal