# amd64 causing kernel panics on Core 2 Duo

## pseudorandom

I have been running Gentoo amd64 successfully on my Athlon-FX machine for years, and have never had any serious issues.  I got a new laptop with a Core2Duo chip in it in January, and naturally, I wanted to see what it could do with a slick Gentoo install.  I generally install from stage1 (using a stage 3 tarball as is now suggested), and I managed to bootstrap, emerge -e system, build a kernel and reboot into my system with no issues.  I noticed right away that the machine would periodically lock up, totally block me out, and just flash the CapsLock light at me.  I did some checking, and this is a sure sign of a kernel panic.  The errors I was getting were of the "could not handle kernel null pointer dereference" type, and happened in seemingly random different functions (I could usually read the backtraces in the dump).  I can't reproduce the output since it kills my machine, causing me to have to hard reboot.  I have tried to find an event that triggers this, but it is totally random, the only prerequisite is that the CPU is loaded at the time.  I thought heat might be the problem, but I instaled a 32-bit version of Gentoo in the exact same way (identical kernels configs as much as is possible between 64 and 32).  Since then, I have had no problems, none.  Not one panic, not one crash.  It works beautifully.  My only problem, I should be able to run 64-bit on this 64-bit machine.  I have tried all the other distros I could get my hands on (Ubuntu Edgy, Feisty 64-bit, Fedora 5, 6, 7, 64-bit to name a few significant ones) and they all kernel panic.  I smell a hardware issue, but I was wondering if anyone had any insight.

Thanks,

Kyle

----------

## l1q1d

Which are your CFLAGS?

----------

## pseudorandom

On amd64:

CFLAGS="-02 -msse3 -march=nocona -pipe"

and I've also tried

CFLAGS="-02 -march=nocona -pipe"

On x86:

CFLAGS="-02 -msse3 -march=prescott -pipe -fomit-frame-pointer"

----------

## l1q1d

 *pseudorandom wrote:*   

> 
> 
> CFLAGS="-02 -march=nocona -pipe"
> 
> 

 

Do you recompile all the system with these flags?

----------

## Genone

CFLAGS don't matter here as it's a) a kernel issue, and the kernel doesn't use CFLAGS from make.conf and b) it's reproducable across distributions.

----------

