Dual Opteron system will not run SMP

[Jack Vogel]

On 6/5/06, Pete French <petefrench at ticketswitch.com> wrote:
> > You say you can boot 'safe', can you boot with just ACPI disabled?
>
> Not using an SMP kernel, no. I did another experiment though, I
> installed amd64 onto an IDe drive, and that will boot SMP with
> APCI disabled, but still only recognises a single processor.
>
> > One suggestion, boot in SAFE or non-ACPI, then do a pciconf -l and
> > look for pci devices that are unknown. At least that will give more
> > evidence.
>
> O.K, will give that a shot later this evening.
>
> > Hard to say if its ACPI or PCI related. Uh, you did make sure you
> > have the latest BIOS for your motherboard right?
>
> Yup - first thing I did. I also asked if other people are using this, and
> Soren apparently uses it (for amd64), so it preseumably does work!

We (Intel networking group) have seen issues with SMP and amd64
as well, although I dont know that its fully characterized (what works
and what doesnt) yet.

If just non-ACPI isnt sufficient, the other thing SAFE does is turn
off disk DMA. I have an as-yet unreleased system that has this
same type of issue, and the problem is that two PCI device ID's
are not recognized, so maybe that will be your problem.

Jack