[CentOS] smp falls back to up mode on quad core

Tue May 27 20:02:44 UTC 2008
Julian Echave <julian.echave at gmail.com>

Sure, find below, I add other stuff as well. Note that there is some bug in
the Bios. This does not prevent Centos to boot, and, since Windows sees all
four processors, I reckon it shouldn't be the problem...?

uname -a

Linux localhost.localdomain 2.6.18-53.1.21.el5PAE #1 SMP Tue May 20 10:03:06
EDT 2008 i686 i686 i386 GNU/Linux

cat  /proc/cpuinfo

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 15
model name    : Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz
stepping    : 11
cpu MHz        : 2400.184
cache size    : 4096 KB
physical id    : 0
siblings    : 1
core id        : 0
cpu cores    : 1
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 10
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc
up pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips    : 4802.08

Linux version 2.6.18-53.1.21.el5PAE (mockbuild at builder6.centos.org) (gcc
version 4.1.2 20070626 (Red Hat 4.1.2-14)) #1 SMP Tue May 20 10:03:06 EDT
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 00000000cf213000 (usable)
 BIOS-e820: 00000000cf213000 - 00000000cf215000 (reserved)
 BIOS-e820: 00000000cf215000 - 00000000cf2c8000 (usable)
 BIOS-e820: 00000000cf2c8000 - 00000000cf3e5000 (ACPI NVS)
 BIOS-e820: 00000000cf3e5000 - 00000000cf3e8000 (usable)
 BIOS-e820: 00000000cf3e8000 - 00000000cf3f3000 (ACPI data)
 BIOS-e820: 00000000cf3f3000 - 00000000cf3f4000 (usable)
 BIOS-e820: 00000000cf3f4000 - 00000000cf3ff000 (ACPI data)
 BIOS-e820: 00000000cf3ff000 - 00000000cf400000 (usable)
 BIOS-e820: 00000000cf400000 - 00000000d0000000 (reserved)
 BIOS-e820: 00000000f0000000 - 00000000f8000000 (reserved)
 BIOS-e820: 00000000fff00000 - 0000000100000000 (reserved)
 BIOS-e820: 0000000100000000 - 000000012c000000 (usable)
3904MB HIGHMEM available.
896MB LOWMEM available.
found SMP MP-table at 000fe200
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
disabling kdump
NX (Execute Disable) protection: active
On node 0 totalpages: 1228800
  DMA zone: 4096 pages, LIFO batch:0
  Normal zone: 225280 pages, LIFO batch:31
  HighMem zone: 999424 pages, LIFO batch:31
DMI 2.4 present.
Using APIC driver default
Intel MultiProcessor Specification v1.4
    Virtual Wire compatibility mode.
OEM ID:  Product ID:  APIC at: 0xFEE00000
Processor #0 6:15 APIC version 20
Enabling APIC mode:  Flat.  Using 0 I/O APICs
BIOS bug, no explicit IRQ entries, using default mptable. (tell your hw
Processors: 1
Allocating PCI resources starting at d2000000 (gap: d0000000:20000000)
Detected 2400.184 MHz processor.
Built 1 zonelists.  Total pages: 1228800
Kernel command line: ro root=/dev/VolGroup00/LogVol00 acpi=off rhgb quiet
mapped APIC to ffffd000 (fee00000)
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Initializing CPU#0
CPU 0 irqstacks, hard=c0740000 soft=c0720000
PID hash table entries: 4096 (order: 12, 16384 bytes)
Console: colour VGA+ 80x25
Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
Memory: 4067796k/4915200k available (2078k kernel code, 46260k reserved,
859k data, 220k init, 3197740k highmem)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Calibrating delay using timer specific routine.. 4802.08 BogoMIPS
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: 512
CPU: After generic identify, caps: bfebfbff 20100000 00000000 00000000
0000e3bd 00000000 00000001
CPU: After vendor identify, caps: bfebfbff 20100000 00000000 00000000
0000e3bd 00000000 00000001
monitor/mwait feature present.
using mwait in idle threads.
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 4096K
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 0
CPU: After all inits, caps: bfebfbff 20100000 00000000 00000940 0000e3bd
00000000 00000001
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
Checking 'hlt' instruction... OK.
SMP alternatives: switching to UP code
Freeing SMP alternatives: 13k freed
CPU0: Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz stepping 0b
Total of 1 processors activated (4802.08 BogoMIPS).
Brought up 1 CPUs
sizeof(vma)=88 bytes
sizeof(page)=32 bytes
sizeof(inode)=340 bytes
sizeof(dentry)=136 bytes
sizeof(ext3inode)=492 bytes
sizeof(buffer_head)=52 bytes
sizeof(skbuff)=172 bytes
checking if image is initramfs... it is
Freeing initrd memory: 2986k freed
NET: Registered protocol family 16
ACPI Exception (utmutex-0262): AE_BAD_PARAMETER, Thread C3689AA0 could not
acquire Mutex [2] [20060707]
ACPI Exception (utmutex-0262): AE_BAD_PARAMETER, Thread C3689AA0 could not
acquire Mutex [2] [20060707]
PCI: Using configuration type 1
Setting up standard PCI resources
ACPI: Interpreter disabled.
Linux Plug and Play Support v0.97 (c) Adam Belay
pnp: PnP ACPI: disabled
usbcore: registered new driver usbfs
usbcore: registered new driver hub
PCI: Probing PCI hardware
PCI: Probing PCI hardware (bus 00)

On Tue, May 27, 2008 at 4:47 PM, John R Pierce <pierce at hogranch.com> wrote:

> Julian Echave wrote:
>> Hi,
>>  I'm running Centos 5.1 on an Intel Quad 2 Core with four Q6600
>> processors.
>> Despite Centos 5 supporting multiple cores (SPM), it doesn't seem to work
>> for me:
>> 1) a dmesg shows that only one processor is seen:
>>     "SPM alternatives: switching to UP code", etc.
>> 2) file /proc/cpuinfo shows only one processor
>> 3) top with option 1 (to toggle between seeing all processors or an
>> average) shows only 1 processor.
>>  I've googled this, and other people have found this kind of trouble, but
>> I was not able to find any solutions.
> it might help diagnose this if you paste the output of  'dmesg' at least up
> to that "SMP Alternatives" message and maybe a couple more lines after it...
> _______________________________________________
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> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
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