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opnickc 08-11-2020 11:46 AM

Netrunner 20 (debian 10) only sees one CPU core on 4-core system
 
Heya,

I'm trying to get Netrunner set up on an old server (craigslist find). I was able to get it installed and running, but the OS only sees one CPU core.

The system has two 771 sockets with a Xeon 5140 in each, so a total of 4 cores (I have a pair of E5472's on the way so I can up that to 8 cores). Both CPUs show up in the BIOS so no issues there. As I said before though, only one core is detected by the OS.

Some googling suggested that maybe ACPI wasn't enabled, so I added 'acpi=on' to my grub config. Is there something else I need to do? I'm at a little bit of a loss since I'd expect SMT to be enabled by default on any modern kernel, and it seems like most posts describing similar issues are from the early 2000s.

I'm running kernel 4.19.0-8-amd64. Any help is appreciated!

Ser Olmy 08-11-2020 11:16 PM

How did you determine that the kernel only sees one CPU core? What does cat /proc/cpuinfo return? And what does dmidecode report?

Have you tried booting a live distribution with a more recent kernel, like System Rescue CD?

opnickc 08-12-2020 08:24 AM

dmidecode shows the correct info (two dual-core CPUs), while /proc/cpuinfo shows a single CPU with a single core:

Code:

[root@sysresccd ~]# cat /proc/cpuinfo
processor        : 0
vendor_id        : GenuineIntel
cpu family        : 6
model                : 15
model name        : Intel(R) Xeon(R) CPU            5140  @ 2.33GHz
stepping        : 6
microcode        : 0xd2
cpu MHz                : 2000.080
cache size        : 4096 KB
physical id        : 0
siblings        : 1
core id                : 0
cpu cores        : 1
apicid                : 0
initial apicid        : 0
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 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 lahf_lm pti tpr_shadow dtherm
bugs                : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips        : 4666.85
clflush size        : 64
cache_alignment        : 64
address sizes        : 36 bits physical, 48 bits virtual
power management:

[root@sysresccd ~]#


[root@sysresccd ~]# dmidecode -t processor
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.4 present.

Handle 0x0400, DMI type 4, 40 bytes
Processor Information
        Socket Designation: Proc 1
        Type: Central Processor
        Family: Xeon
        Manufacturer: Intel
        ID: F6 06 00 00 FF FB EB BF
        Signature: Type 0, Family 6, Model 15, Stepping 6
        Flags:
                FPU (Floating-point unit on-chip)
                VME (Virtual mode extension)
                DE (Debugging extension)
                PSE (Page size extension)
                TSC (Time stamp counter)
                MSR (Model specific registers)
                PAE (Physical address extension)
                MCE (Machine check exception)
                CX8 (CMPXCHG8 instruction supported)
                APIC (On-chip APIC hardware supported)
                SEP (Fast system call)
                MTRR (Memory type range registers)
                PGE (Page global enable)
                MCA (Machine check architecture)
                CMOV (Conditional move instruction supported)
                PAT (Page attribute table)
                PSE-36 (36-bit page size extension)
                CLFSH (CLFLUSH instruction supported)
                DS (Debug store)
                ACPI (ACPI supported)
                MMX (MMX technology supported)
                FXSR (FXSAVE and FXSTOR instructions supported)
                SSE (Streaming SIMD extensions)
                SSE2 (Streaming SIMD extensions 2)
                SS (Self-snoop)
                HTT (Multi-threading)
                TM (Thermal monitor supported)
                PBE (Pending break enabled)
        Version: Not Specified
        Voltage: 1.4 V
        External Clock: 1333 MHz
        Max Speed: 4800 MHz
        Current Speed: 2333 MHz
        Status: Populated, Enabled
        Upgrade: Socket LGA771
        L1 Cache Handle: 0x0710
        L2 Cache Handle: 0x0720
        L3 Cache Handle: 0x0730
        Serial Number: Not Specified
        Asset Tag: Not Specified
        Part Number: Not Specified
        Core Count: 2
        Core Enabled: 2
        Thread Count: 2
        Characteristics:
                64-bit capable

Handle 0x0406, DMI type 4, 40 bytes
Processor Information
        Socket Designation: Proc 2
        Type: Central Processor
        Family: Xeon
        Manufacturer: Intel
        ID: F6 06 00 00 FF FB EB BF
        Signature: Type 0, Family 6, Model 15, Stepping 6
        Flags:
                FPU (Floating-point unit on-chip)
                VME (Virtual mode extension)
                DE (Debugging extension)
                PSE (Page size extension)
                TSC (Time stamp counter)
                MSR (Model specific registers)
                PAE (Physical address extension)
                MCE (Machine check exception)
                CX8 (CMPXCHG8 instruction supported)
                APIC (On-chip APIC hardware supported)
                SEP (Fast system call)
                MTRR (Memory type range registers)
                PGE (Page global enable)
                MCA (Machine check architecture)
                CMOV (Conditional move instruction supported)
                PAT (Page attribute table)
                PSE-36 (36-bit page size extension)
                CLFSH (CLFLUSH instruction supported)
                DS (Debug store)
                ACPI (ACPI supported)
                MMX (MMX technology supported)
                FXSR (FXSAVE and FXSTOR instructions supported)
                SSE (Streaming SIMD extensions)
                SSE2 (Streaming SIMD extensions 2)
                SS (Self-snoop)
                HTT (Multi-threading)
                TM (Thermal monitor supported)
                PBE (Pending break enabled)
        Version: Not Specified
        Voltage: 1.4 V
        External Clock: 1333 MHz
        Max Speed: 4800 MHz
        Current Speed: 2333 MHz
        Status: Populated, Idle
        Upgrade: Socket LGA771
        L1 Cache Handle: 0x0716
        L2 Cache Handle: 0x0726
        L3 Cache Handle: 0x0736
        Serial Number: Not Specified
        Asset Tag: Not Specified
        Part Number: Not Specified
        Core Count: 2
        Core Enabled: 2
        Thread Count: 2
        Characteristics:
                64-bit capable

[root@sysresccd ~]#


Ser Olmy 08-12-2020 11:32 AM

That's weird. The 5140 is a dual-core CPU, so even in the event that some odd BIOS incompatibility prevents the kernel from seeing the second socket, at least both cores on CPU0 ought to be enabled.

Does dmesg | grep smp return anything at all? Could you post the first 200 lines from dmesg?

Is this server running the latest available BIOS from the manufacturer?


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