SMP Kernel and ACPI=OFF
 

Hi all, i have an intel core 2 duo processor in a machine with fedora core 7 with a SMP kernel build. The fact is that if i dont pass de acpi=off parameter to the kernel, the system wont boot. Does anyone know why or if there is a way to boot without this parameter, because with the acpi=off the system recognizes only one core of the processor.

Thanks all

Instead of acpi=off, try using :

noapic nolapic

You may also want to try fedora 8 and see if the problem has been corrected.

kilgoretrout what u say about BIOS upgrade if applicable?

If the upgrade addresses problems with acpi, then it's worth a shot. The problem is with the motherboard bios and it's acpi implementation after all. See this for a description of the problem:

http://gentoo-wiki.com/HOWTO_Fix_Com...of_the_Problem

thanks all, ill give it a shot but one thing i can say is that CentOS 5.1 works fine without the acpi=off

It all depends on the kernel. acpi will work just fine on linux with any standards compliant implementation. How the kernel will react to a non-standard implementation of acpi seems to be a crap shoot: sometimes it works; sometimes it doesn't; sometimes it partially works; sometimes it will stop the booting process cold. And the precise behavior varies from kernel to kernel.

indeed, but the thing is that the machine i am trying to get fedora 7 with 2 cores is a DELL optiplex 320 that has reported some issues in order to install any distro. Fedora 7 i can get installed but it only boots with acpi=off and pci=nomsi kernel parameters. In the other hand CentOS 5.1 only needs pci=nomsi, so i can use both cores with it. And to get things uglier i am trying to get rtai installed on this machine, whitch isnt working as well.

Thanks for the attention