Missing 7 of 8 cores on Host.

[Joe Baker]

I'm running a Dell 1950 III - It has two Xenon 5450 quad core cpus.
Because of another bug that makes proxmox not run on Dell 1950's I have had to set a kernel parameter as such:

nolapic

When I run top on a linux machine I press "1" and it shows the utilization statistics for each of the cores.
Only it doesn't on this proxmox build.

I'm logged into the server as root (not a container nor in a VM).

When I type "1" into top... it only shows one core.

I've done so much with efficient LXC containers that honestly I haven't noticed the slowness untill now.


I'm running Proxmox 7.3.6.

I have another installation of proxmox on a laptop with a single quad core cpu. On that installation I get the correct enumeration of cpu cores.

Might this have to do with recently installing two pci card adaptors so I could employ NVMe memory modules?

root@pve9:~# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 2992.570
cache size : 6144 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5985.13
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:



CPUINfO SHOULD show a stanza for each core (each having a unique "processor" id number.

 

[Joe Baker]

cat /sys/devices/cpu/type
4

I have several Dell 1950 III units... So I'll try checking another one.
There was a similar issue on reddit titled "dude where are my cores ?"
https://www.reddit.com/r/debian/comments/smg8uj/dude_where_are_my_cores/

So in that thread they suggested trying a debian live distribution on the server. I'm going to make a bootable memory stick to try this.

 

[Joe Baker]

I tried the pve-kernel-6.0.19-edge still with nolapic option ...
Still get just one core responding.

 

[Joe Baker]

I just tried on another dell 1950 III server.

kernel 5.15.74-1-pve
Also sees only one core.

Oh, by the way it's a bitch to install proxmox on these boxes as the video isn't detected properly. I've seen the problem reported elsewhere in this forum. I managed to work around it by figuring out how to artfully hit the keyboard commands to navigate the inputs during the install questions.

 

[Joe Baker]

OK... problem remediated.
I used the PVE-Edge-Kernel

Verified that I did not need to use

nolapic

when booting from the pve-kernel-6.0.17-edge kernel.

and ...

I see all 8 cores now with top!

And when I inspect /proc/cpuinfo I now see all 8 cores (0-7)


So I've confirmed this on my test server. Now I'm going to verify that it works on the production machine.

 

[Joe Baker]

It's running good so far on 6.0.19-1 on the pve-kernel-edge.

I thought I might have an instability issue but that seemed to be a holdover from the nolapic setting when shutting down a vm.
Now that nolapic is NOT being used I was able to shutdown cleanly the vm and things seem stable.

 

[Joe Baker]

I'm happy to mark this issue closed.

 

[Joe Baker]

here is /proc/cpuinfo now, after running the new kernel:

root@pve9:~# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1994.843
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.53
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1995.011
cache size : 6144 KB
physical id : 1
siblings : 4
core id : 0
cpu cores : 4
apicid : 4
initial apicid : 4
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.61
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 2
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 2534.942
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 2
cpu cores : 4
apicid : 2
initial apicid : 2
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.53
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 3
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1995.439
cache size : 6144 KB
physical id : 1
siblings : 4
core id : 2
cpu cores : 4
apicid : 6
initial apicid : 6
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.61
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 4
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1993.846
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 1
cpu cores : 4
apicid : 1
initial apicid : 1
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.53
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 5
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 2037.269
cache size : 6144 KB
physical id : 1
siblings : 4
core id : 1
cpu cores : 4
apicid : 5
initial apicid : 5
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.61
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 6
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1994.843
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 3
cpu cores : 4
apicid : 3
initial apicid : 3
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.53
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management:

processor : 7
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
stepping : 10
microcode : 0xa07
cpu MHz : 1995.314
cache size : 6144 KB
physical id : 1
siblings : 4
core id : 3
cpu cores : 4
apicid : 7
initial apicid : 7
fpu : yes
fpu_exception : yes
cpuid level : 13
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 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm pti tpr_shadow vnmi flexpriority vpid dtherm
vmx flags : vnmi flexpriority tsc_offset vtpr vapic
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
bogomips : 5984.61
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
power management: