Processor type?
 

I have just installed Slk 12.0 and was configuring the Kernel when i noticed that the processor type Pentium Pro was checked. No biggie i will just change it to Athlon/K8. recompile, reboot, then BAM. i get a whole bunch of Error messages saying that it should be a M686 not a K8 and that it was Unloading all the Modules, etc. So i go back and recompile through the menuconfig and switch it back to the Pentium Pro and now everything works fine. Any sugestions on why it is doing this?
--specs--

Laptop Rig
AMD Semperon 3000+ 1.8ghz
768mb ram
ATI 200M
other things non-related.

Becourse your processor family name is Athlon64/Opteron (or something like that, I don't remember exactly).

Yeah, it's not that straightforward. The name your CPU "has" might not be the actual name of the thing used. Before changing vital things like that in your kernel, be sure to carefully find out what your processor exactly is, unless there's a choice which matches your (thought) cpu 100%. Shortly, if there is no "Sempron" choice, you can't just pick up some other AMD "close to that", unless you're begging for trouble :)

The fact is there were 2 flavours of Sempron. One was a stripped down K8 (Athlon 64/X2, Opteron) CPU while the other was based on a K7 architecture (Athlon, Athlon 4, Athlon XP,...). I think you choose the K8 architecture type while your CPU is actually a K7 which then mess up the kernel loading.
You should try to compile your kernel and tell him you've got an Athlon XP.

ok ill give it a try. this is a socket 754 processor (acording to CPUZ) and that was the socket right after the Athlon XPs so i will give the K7 option a try and see how it goes. Thanks for the replies.

Oh, if it is a socket 754 then it is a K8 based Sempron... Are you sure to have compiled the modules for your CPU architecture?

yeah i think so. after i save the kernel i went "make modules && make modules_install" if that is what you mean. if not what should i enable for the architecture?

ahhhhh. kernel panic. my kernel is panicing on shutdown and i have no clue on what to do. any ideas?

You have a K7! So you need to select K7.

There are actually three versions of the Sempron:
1) Socket A K7 Sempron.
2) Socket 754 based on the K8 but with 64-bit extensions disabled Sempron. It has all the capabilities of a K8 except 64-bit so you treat it as a K7.
3) Socket 754 K8 64-bit Sempron.

The reason I know of #2 is because I have a laptop with one :)

whoops.
just disassembled my laptop (upgrading reasons) and i have a socket 939 sempy which means its K8. but i will be upgrading it in the very near future to a athlon. *hops on newegg*

Well I didn't know there were any socket 939 Sempron. It's also strange, I thought there were a specific socket for the laptop CPU. To add to the confusion, I checked an online store and just discovered some Sempron are available on socket AM2...
Anyway, even if a K8 is a K7 which architectural ameliorations and an integrated memory controller, I think it is still important to try both options and be sure all the modules are compiled and installed in the same time as the kernel itself. Anyway, it's pretty strange; after all, they're all x86 CPU based on more or less the same architecture flavour, you might have misconfigured other options in the kernel which causes all theses problems and might have nothing to do with the target CPU chosen.

well i did try it with both versions. and upon boot up it would (depending on the option i chose) either say <module> Unloading /2.6.21.5-smp/unload-k7(k8) error, should be <module> unloading /2.6.21.5/ unload-686. or something along the lines of that.