[SOLVED] CentOS 7 does not detect new CPU on motherboard

[rajatkmitra]

Hello,
I have a dual socket ASUS Z8PE-D18 motherboard. Initially it had just a single Xeon 5690 CPU and 24GB of memory. This morning I added a second Xeon 5690 CPU on the second socket and an additional 24GB of memory . On booting with the additional CPU and extra 24GB of memory, I am unable to see the new CPU. Here is what /proc/cpuinfo looks like -
==========================================================
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 44
model name : Intel(R) Xeon(R) CPU X5690 @ 3.47GHz
stepping : 2
microcode : 0x13
cpu MHz : 3466.806
cache size : 12288 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
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 syscall nx pdpe1gb rdtscp lm consta
nt_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1
sse4_2 popcnt aes lahf_lm epb tpr_shadow vnmi flexpriority ept vpid dtherm ida arat
bogomips : 6933.61
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
=========================================================================

When I run dmidecode (relevant info only), I most certainly see the new CPU ---

Handle 0x0004, DMI type 4, 40 bytes
Processor Information
Socket Designation: CPU 1
Type: Central Processor
Family: Xeon
Manufacturer: Intel
ID: C2 06 02 00 FF FB EB BF
Signature: Type 0, Family 6, Model 44, Stepping 2
Flags:

Handle 0x0008, DMI type 4, 40 bytes
Processor Information
Socket Designation: CPU 2
Type: Central Processor
Family: Xeon
Manufacturer: Intel
ID: C2 06 02 00 FF FB EB BF
Signature: Type 0, Family 6, Model 44, Stepping 2
Flags:


Is there something else that I have to do for CentOS to use both processors?? Do I have to reinstall the OS??
uname -a dumps the following info -

[rajatkmitra@butterfly proc]$ uname -a
Linux butterfly 3.10.0-862.11.6.el7.x86_64 #1 SMP Tue Aug 14 21:49:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


Any help would be highly appreciated...
Thanks,
Raj

[TrevorH]

Is that all of /proc/cpuinfo or are the other 5 cores in the detected socket seen as well?

Do you have the latest BIOS (appears to be 2001 dated 2012/08/17)? What's the content of /proc/cmdline?

[hunter86_bg]

Have you checked thoroughly the 'dmesg'?
Also you can check it with:

Code: Select all

journalctl -k

[rajatkmitra]

Is that all of /proc/cpuinfo or are the other 5 cores in the detected socket seen as well?

Do you have the latest BIOS (appears to be 2001 dated 2012/08/17)? What's the content of /proc/cmdline?

Hi Trevor,
1. Yes that's all that /proc/cpuinfo has.
2. This is what /proc/cmdline announces -

[rajatkmitra@butterfly ~]$ cd /proc/
[rajatkmitra@butterfly proc]$ more cmdline
BOOT_IMAGE=/vmlinuz-3.10.0-862.11.6.el7.x86_64 root=/dev/mapper/centos-root ro crashkernel=auto rd.lvm.lv=centos/root
rd.lvm.lv=centos/swap nomodeset rhgb quiet LANG=en_US.UTF-8
[rajatkmitra@butterfly proc]$

[rajatkmitra]

Have you checked thoroughly the 'dmesg'?
Also you can check it with:

Code: Select all

journalctl -k

Hi Hunter86,
I checked the output of dmesg and journalctl. While there is advisory that 1 CPUis brought up there does not seem to be any error messages indicating the other CPU was not able to boot. Perhaps you can find something I missed. I am attaching dmesg.out, journalctl.out and dmidecode.out for your perusal. Many thanks for your help!!!

--Raj

[TrevorH]

[ 0.000000] ACPI: No APIC-table, disabling MPS
[ 0.000000] ACPI: HPET id: 0x8086a301 base: 0xfed00000
[ 0.082922] smpboot: SMP motherboard not detected
[ 0.183960] smpboot: SMP disabled
[ 0.185158] Brought up 1 CPUs
[ 0.185160] smpboot: Max logical packages: 1
[ 0.185162] smpboot: Total of 1 processors activated (6933.07 BogoMIPS)

Do you have an options in your BIOS settings for APIC and/or x2apic. Try tweaking those one at a time if so. If those don't help try apending acpi=off to the kernel command line at the grub menu and see if that helps.

[rajatkmitra]

[ 0.000000] ACPI: No APIC-table, disabling MPS
[ 0.000000] ACPI: HPET id: 0x8086a301 base: 0xfed00000
[ 0.082922] smpboot: SMP motherboard not detected
[ 0.183960] smpboot: SMP disabled
[ 0.185158] Brought up 1 CPUs
[ 0.185160] smpboot: Max logical packages: 1
[ 0.185162] smpboot: Total of 1 processors activated (6933.07 BogoMIPS)

Do you have an options in your BIOS settings for APIC and/or x2apic. Try tweaking those one at a time if so. If those don't help try apending acpi=off to the kernel command line at the grub menu and see if that helps.

Hi Trevor and Hunter_86,
Many thanks for the pointers!! I realized ACPI was by default disabled! I turned on ACPI and got all the CPUS to come up -
Best wishes,
Raj

[ 0.000000] Using ACPI (MADT) for SMP configuration information
[ 0.000000] ACPI: HPET id: 0x8086a301 base: 0xfed00000
[ 0.000000] smpboot: Allowing 24 CPUs, 0 hotplug CPUs
[ 0.000000] PM: Registered nosave memory: [mem 0x0009e000-0x0009efff]
[ 0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000e3fff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000e4000-0x000fffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf780000-0xbf78dfff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf78e000-0xbf78ffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf790000-0xbf79dfff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf79e000-0xbf7cffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf7d0000-0xbf7dffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf7e0000-0xbf7ebfff]
[ 0.000000] PM: Registered nosave memory: [mem 0xbf7ec000-0xbfffffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xc0000000-0xdfffffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xe0000000-0xefffffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xf0000000-0xfedfffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xfee00000-0xfee00fff]
[ 0.000000] PM: Registered nosave memory: [mem 0xfee01000-0xffdfffff]
[ 0.000000] PM: Registered nosave memory: [mem 0xffe00000-0xffffffff]