Re: problem on dell r610

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

On Tue, Nov 02, 2010 at 05:48:38PM +1300, Mark Davies wrote:
> I have a Dell PowerEdge r610 running 5.1_RC4/amd64 GENERIC happily 
> (initial part of dmesg included below) but if I try to boot XEN3_DOM0 
> (with the xen 3.3.2 xenkernel) it dies very quickly with the 
> following backtrace:
> 
> breakpoint()
> panic()
> cpu_attach()
> config_attach_loc()
> mpacacpi_config_cpu()
> acpi_madt_walk()
> mpacpi_scan_apics()
> mainbus_attach()
> config_attach_loc()
> cpu_configure()
> main()
> 
> a very similar machine tripped over the problem fixed in r1.11 of 
> src/sys/arch/x86/x86/intel_busclock.c when I first got that box so 
> maybe some similar but xen specific issue?

This is specific to ACPI -- or more specifically, configuration of the Intel
APIC system through ACPI. Can someone clarify how and why Xen tries to use
"mpacpi" (or ACPI at all) without LAPIC? In other words, I think we might
hit this #ifdef (mpacpi.c):

   312  #if defined(MULTIPROCESSOR) || defined(IOAPIC)
   313          if (mpacpi_ncpu > 1)
   314                  cpunum = lapic_cpu_number();
   315  #endif

- Jukka.