# Kernel Panic - not syncing: Fatal exception in interrupt

## Cyker

Hi,

I've recently been getting kernel panics with the above message; Unfortunately the info dumped to the screen doesn't seem to make it to the messages/kern.log file and because the console is only 80x25 I'm missing a lot of info.

About the only interesting data that is saved is the kernel panic thing 

```
Kernel Panic - not syncing: Fatal exception in interrupt

Pid: 22114, comm: ktorrent Tainted: G
```

 and the Call Trace:

```
panic

oops_end

no_context

__bad_area_nosemaphore

check_preempt_wakeup

try_to_wake_up

do_page_fault

bad_area_nosemaphore

error_code

dev_kfree_skb_irq

nv_tx_done_optimized

nv_napi_poll

__qdisc_run

net_rx_action

__do_softirq

do_softirq

irq_exit

do_IRQ

common_interrupt
```

The kernel is the latest stable for x86; gentoo-sources-2.6.30-r8

I'm trying to figure out why it happens; Seems to only happen when the network is under heavy load (This system has a bridge, br0, which is made up of a 3com 3c905b on coaxial and the two onboard gigabit ethernet controllers).

There have been a lot of changes since when I started getting this problem, but the two main ones I can think of are the upgrade of the kernel to this version, and the changing of the motherboard to an A8N-SLI Premium.

Changing the motherboard is a lot of work; Does it seem like it is the likely cause? I am trying to avoid changing it and then finding I still have the same problem!  :Sad: 

Any suggestions of other stuff that I can try?

----------

## Arthanis

Have you rebuilt your kernel since the motherboard upgrade? Its worth a shot, since much of your hardware must have changed.

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## Cyker

Yes I did; Changed the Sil SATA driver to the older one, and the sky2 NIC driver to the skge one.

Also had to rejig a couple of other things (e.g. lm_sensors) to make it work, but tbh the two motherboards were very similar...

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## Arthanis

Well, it seems to have something to do with your network, try bo blacklist your NIC modules to see if it boots, or building a kernel without it, just to isolate the problem.

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## Cyker

Welp, since it keeps happening on the nvidia NIC, which is also the most heavily loaded one, it's been suggested that I swap the cables over so I've done that to see if it's any more stable...

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## Vieri

I'm experiencing similar kernel panics but with telephony cards.

I would like to ask a different question, though (I don't want to hijack this thread but I thought that my question could be of common interest).

How can one "dump" a kernel panic to disk so it can be analyzed later on?

Better yet, how can one dump the data and have the system auto-reboot? (useful if a production system kernel panics at 03:00 am)

Gentoo portage does have tools such as http://www.kerneloops.org/ but I don't think that they can dump a kernel panic that doesn't write anything to /var/log/messages.

I've been pointed to http://lse.sourceforge.net/kdump/ as an alternative but I don't know yet how to effectively use it.

Is there a Gentoo-oriented guide to "kernel disasters"?

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## Hu

If the system is in such a bad shape that the kernel panics, do you really want to trust it to write to your filesystem?

You can enable automatic reboot on panic, but then you will lose the opportunity to read the screen before it reboots.  You might be able to save the panic text using a serial console or using netconsole, but I have not tried that.

----------

