Help my SMP is broken???

[Willem Jan Withagen]

> From: "John Baldwin" <jhb at FreeBSD.org>
> > On Tuesday 13 July 2004 09:22 am, Willem Jan Withagen wrote:
> > > > I'm trying to boot my dual opteron box with a recent kernel.
> > > > Without ACPI is boots single processor, with ACPI I get the stuff
> > > > downbelow.
> > > > ACPI APIC Table: <VIAK8  AWRDACPI>
> > > > panic: AP #1 (PHY# 1) failed!
> > > > cpuid = 0;
> > > > Stack backtrace:
> > > > backtrace() at backtrace+0x17
> > > > panic() at panic+0x1d2
> > > > start_all_aps() at start_all_aps+0x187
> > > > cpu_mp_start() at cpu_mp_start+0x199
> > > > mp_start() at mp_start+0x54
> > > > mi_startup() at mi_startup+0xb8
> > > > btext() at btext+0x2c
> > > > Debugger("panic")
> > > > Stopped at      Debugger+0x4d:  xchgl   %ebx,0x27d461
> > >
> > > I'm trying to figure this one out.....
> > > So I added a printf into init_secondary. This is namely the place where a
> > > variable (mp_naps) is incremented to make it out of the waiting loop in
> > > start_all_aps.
> > >
> > > BUT we never get to init_secondary, which I expected to be called from an
> > > interrupt routine. ini_secondary is called from an asm-sequence in
mpboot.S
> > > which suggest that it is the first thing to be called once we get into
> > > 64bit mode???
> > >
> > > Is there anywhere a description on how booting is done on UP or SMP (let
> > > alone SMP amd64??)
> >
> > Basically, when a CPU is started up, it starts up in 8086-style real mode
> > executing the code in mpboot.s.  That code brings the computer into
protected
> > mode and eventually into the same virtual addresses used by the kernel (the
> > mpboot code is dual-mapped to allow for this transition).  At that point the
> > AP can safely call into the kernel and it calls init_secondary().  If the AP
> > faults during the early boot code it will basically die and never get into
> > init_secondary().  Also, if the IPI is somehow lost then it will never get
> > into init_secondary().
>
> Some of this I sort figured from comments in mpboot.s
>
> So any suggestions on how to debug this...
> Or could this be broken hardware:
>     CPU
>     APIC
>     Motherboard
>     ????
>
> I'll try and boot
>  - the amd64 version of Windows XP, to see what happens.
>  - FreeBSD/amd64 in UP with APCI
> and see what goes??
>
> What exactly is the AP??? and what is an IPI??
> Perhaps stuppid questions, but I'm sort of 10 years out of processors and
stuff.

Well, booting Windows/64 XP seems to be a good "heilmeister" for the trouble:

real memory  = 2146304000 (2046 MB)
Physical memory chunk(s):
0x0000000000001000 - 0x000000000009bfff, 634880 bytes (155 pages)
0x000000000074c000 - 0x000000007c2b7fff, 2075574272 bytes (506732 pages)
avail memory = 2062815232 (1967 MB)
ACPI APIC Table: <VIAK8  AWRDACPI>
SMP: bootAP CPU #1 Trying to launch!
APIC ID: physical 0, logical 0:0
APIC ID: physical 1, logical 0:1
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1
APIC: CPU 0 has ACPI ID 0
APIC: CPU 1 has ACPI ID 1
MADT: Found IO APIC ID 2, Interrupt 0 at 0xfec00000

And now the box just boots fine???

Any suggestions what XP might have fixed???? Can't be that a firmware setting is
sticky and windows unglued it?!

--WjW