SMP only detects one CPU - help?

Adam J Richardson at
Fri Apr 20 16:42:02 UTC 2007

Hi all,

Firstly, apologies for the length of this. It's my first mailing list 
posting, so I hope I'm not breaching any etiquette codes. Also I've only 
been using FreeBSD for a couple of years, so I'm still very new to the 

I have recently become the proud owner of a second-hand HP NetServer 
e800, which has two Pentium-III class [686] CPUs in it. I've installed 
6.2-RELEASE-p3 [which is also referred to as 6.2-STABLE, is that 
correct?] and built myself a SMP kernel. I'm sure it's a SMP kernel, 
because the config file has "options SMP" in it and while running it 
"sysctl kern.smp.maxcpus" returns 16. The BIOS says there are two CPUs, 
so I guess the second CPU is in fine condition and ready to go.

I've done a little Googling and digging around in the system. First, the 
obligatory "uname -a" output:

"FreeBSD 6.2-RELEASE-p3 FreeBSD 6.2-RELEASE-p3 #0: 
Tue Apr 17 15:01:06 BST 2007 
fatman at  i386"

There's nothing in /var/log/messages about CPUs, as far as I can tell.

The output of "dmesg" provides a possible clue:

"real memory  = 268369920 (255 MB)
avail memory = 257167360 (245 MB)
MADT: Forcing active-low polarity and level trigger for SCI
ioapic0 <Version 1.1> irqs 0-15 on motherboard
ioapic1 <Version 1.1> irqs 16-31 on motherboard
kbd1 at kbdmux0
acpi0: <HP HWPC20F> on motherboard
acpi0: Power Button (fixed)
unknown: I/O range not supported
can't fetch resources for \\_SB_.PCI0.ISA_.SIO_.LPT_ - 
Timecounter "ACPI-safe" frequency 3579545 Hz quality 1000
acpi_timer0: <32-bit timer at 3.579545MHz> port 0x1208-0x120b on acpi0
cpu0: <ACPI CPU> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci_link0: BIOS IRQ 10 for 0.15.INTA is invalid"

Several possible clues in that snippet, now that I look at it. The 
"MADT" line is suspicious but I think the real culprit might be revealed 
in the "can't fetch resources" line. On the other hand it might be a 
completely unrelated problem. Google is silent on the subject of 
"AE_AML_INVALID_RESOURCE_TYPE", and I don't see it in the Lehey or Lucas 

Finally, mptable shows what's really going on:
"MP Config Base Table Entries:
Processors: APIC ID Version State        Family Model Step Flags
              3       0x11    BSP, usable  6      8     3    0x387fbff
              0       0x11    AP, unusable 6      8     3    0x387fbff"

Apparently the "application processor" is "unusable", whatever that 
means. I am now stuck.

Is there a software fix for this, or do I have a broken CPU, unlikely as 
it seems? Any help is appreciated.

Does it seem likely that upgrading both CPUs to the highest Pentium-IIIs 
I can find, which I was thinking about doing anyway, would fix the problem?

Adam J Richardson

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