Re: 2.6.16rc5 'found' an extra CPU.

From: Ashok Raj
Date: Thu Mar 02 2006 - 11:28:35 EST


On Wed, Mar 01, 2006 at 09:49:53PM -0800, Brown, Len wrote:
>
> >sysfs gets it right.
> >
> >(23:11:01:davej@nemesis:~)$ ls /sys/devices/system/cpu/
> >cpu0/ cpu1/
> >(23:11:07:davej@nemesis:~)$ ls /proc/acpi/processor/
> >CPU1/ CPU2/ CPU3/
>
> This is because the BIOS has three "Processor" objects in the DSDT.
>

I have a dual core + HT platform. I disabled HT to have the same situation
as Dave.

ACPI DSDT dump shows 4 objects in \_PR scope as below.

Scope (\_PR)
{
Processor (CPU0, 0x01, 0x00000410, 0x06) {}
Processor (CPU1, 0x02, 0x00000410, 0x06) {}
Processor (CPU2, 0x03, 0x00000410, 0x06) {}
Processor (CPU3, 0x04, 0x00000410, 0x06) {}
}

Only 2 are marked enabled in the ACPI MADT..

>From boot log

ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled)
Processor #0 15:4 APIC version 20
ACPI: LAPIC (acpi_id[0x03] lapic_id[0x02] enabled)
Processor #2 15:4 APIC version 20
ACPI: LAPIC (acpi_id[0x02] lapic_id[0x01] disabled)
ACPI: LAPIC (acpi_id[0x04] lapic_id[0x03] disabled)

But proc/acpi/processor also lists just 2 entries.

[root@araj-sfield-2 tmp]# ls /proc/acpi/processor/
CPU0 CPU2

I suspect that the BIOS is goofy and sending a valid acpiid when we try
to evaluate the processor object.

Could you see what comes out of the /proc/acpi/processor/CPUx/info for all the
3 listed in your system?

Also if you can send DSDT dump just to look over.

Cheers,
ashok
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