Centos 5.3 - 2 CPUs are missing on AMD Phenom II X4

[bzzik]

Hi guys!

Not so long time ago I have installed Centos 5.3 on my AMD Phenom II X4 server (I am hosting game servers on it). Only today I noticed, that cpuinfo shows me only two CPUs. I watched for the info in the dmesg and found there that the system boots up only 2CPUs.

Here is some info from the dmesg:

Linux version 2.6.18-164.11.1.el5 (gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)) #1 SMP Wed Jan 20 07:32:21 EST 2010

ACPI: Local APIC address 0xfee00000
ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
Processor #0 0:4 APIC version 16
ACPI: LAPIC (acpi_id[0x01] lapic_id[0x01] enabled)
Processor #1 0:4 APIC version 16
ACPI: LAPIC (acpi_id[0x02] lapic_id[0x02] disabled)
ACPI: LAPIC (acpi_id[0x03] lapic_id[0x03] disabled)
ACPI: LAPIC_NMI (acpi_id[0x00] dfl dfl lint[0x1])
ACPI: LAPIC_NMI (acpi_id[0x01] dfl dfl lint[0x1])
ACPI: LAPIC_NMI (acpi_id[0x02] dfl dfl lint[0x1])
ACPI: LAPIC_NMI (acpi_id[0x03] dfl dfl lint[0x1])

SMP: Allowing 4 CPUs, 2 hotplug CPUs
Built 1 zonelists. Total pages: 1030756
Kernel command line: ro root=/dev/VolGroup00/LogVol00
Initializing CPU#0
PID hash table entries: 4096 (order: 12, 32768 bytes)
Console: colour VGA+ 80x25
Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes)
Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes)
Checking aperture...
CPU 0: aperture 4000000 size 32 MB
Aperture too small (32 MB)
No AGP bridge found
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Mapping aperture over 65536 KB of RAM 4000000
Nosave address range: 0000000004000000 - 0000000008000000
ACPI: DMAR not present
Memory: 4047512k/4718592k available (2551k kernel code, 145188k reserved, 1290k data, 208k init)
Calibrating delay loop (skipped), value calculated using timer frequency.. 6830.84 BogoMIPS (lpj=3415424)
Security Framework v1.0.0 initialized
SELinux: Initializing.
SELinux: Starting in permissive mode
selinux_register_security: Registering secondary module capability
Capability LSM initialized as secondary
Mount-cache hash table entries: 256
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 512K (64 bytes/line)
CPU 0/0 -> Node 0
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 0
SMP alternatives: switching to UP code
ACPI: Core revision 20060707
Using local APIC timer interrupts.
Detected 12.556 MHz APIC timer.
SMP alternatives: switching to SMP code
Booting processor 1/2 APIC 0x1
Initializing CPU#1
Calibrating delay using timer specific routine.. 6830.83 BogoMIPS (lpj=3415415)
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 512K (64 bytes/line)
CPU 1/1 -> Node 0
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 1
AMD Phenom(tm) II X4 965 Processor stepping 03
Brought up 2 CPUs

Am I correctly understand that something wrong in BIOS? Or it is something else?


Thanks in advance for your support!

UPDATE:
The problem in fact was in BIOS settings. 2 CPUs was disabled in it

[Rubberman]

Sounds like you found what I (and probably others) was going to suggest, that the other CPU's were disabled in the BIOS. This is not uncommon on multi-processor/multi-core systems that are running commercial software that are priced on the number of CPUs/cores that the system is running. Oracle is a good example of this practice.