Enable CPU core on Ubuntu 20.04 LTS Linux

I am working on ubuntu 20.04 LTS installed on a Dell Latitude E6510. The return of a sudo dmidecode -t processor command is shown below.
proc_info

The problem is, I can’t enable both cores at the same time.
Note that I have already run the command echo 1 … but it does not work
Could anyone help me overcome this problem. Thank you in advance

May I know your CPU model? Run the command:

lscpu

And paste output here. Second thing look into grub config. Do you see any CPU (maxcpu) info?

cat /etc/default/grub

Paste that output too.

Of course, here are the two command output:

randrianarivelo@latitude:~$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
Address sizes: 36 bits physical, 48 bits virtual
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 2
Core(s) per socket: 2
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 37
Model name: Intel® Core™ i5 CPU M 560 @ 2.67GHz
Stepping: 5
Frequency boost: enabled
CPU MHz: 1337.310
CPU max MHz: 2667.0000
CPU min MHz: 1199.0000
BogoMIPS: 5319.74
Virtualization: VT-x
L1d cache: 64 KiB
L1i cache: 64 KiB
L2 cache: 512 KiB
L3 cache: 3 MiB
NUMA node0 CPU(s): 0-3
Vulnerability Itlb multihit: KVM: Mitigation: Split huge pages
Vulnerability L1tf: Mitigation; PTE Inversion; VMX conditional cach
e flushes, SMT vulnerable
Vulnerability Mds: Vulnerable: Clear CPU buffers attempted, no mic
rocode; SMT vulnerable
Vulnerability Meltdown: Mitigation; PTI
Vulnerability Spec store bypass: Mitigation; Speculative Store Bypass disabled v
ia prctl and seccomp
Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user
pointer sanitization
Vulnerability Spectre v2: Mitigation; Full generic retpoline, IBPB condit
ional, IBRS_FW, STIBP conditional, RSB filling
Vulnerability Srbds: Not affected
Vulnerability Tsx async abort: Not affected
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtr
r pge mca cmov pat pse36 clflush dts acpi mmx f
xsr sse sse2 ht tm pbe syscall nx rdtscp lm con
stant_tsc arch_perfmon pebs bts rep_good nopl x
topology nonstop_tsc cpuid aperfmperf pni pclmu
lqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse
3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt aes
lahf_lm pti ssbd ibrs ibpb stibp tpr_shadow vnm
i flexpriority ept vpid dtherm ida arat flush_l
1d

randrianarivelo@latitude:~$ cat /etc/default/grub

If you change this file, run ‘update-grub’ afterwards to update

/boot/grub/grub.cfg.

For full documentation of the options in this file, see:

info -f grub -n ‘Simple configuration’

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash”
GRUB_CMDLINE_LINUX=""

Uncomment to enable BadRAM filtering, modify to suit your needs

This works with Linux (no patch required) and with any kernel that obtains

the memory map information from GRUB (GNU Mach, kernel of FreeBSD …)

#GRUB_BADRAM=“0x01234567,0xfefefefe,0x89abcdef,0xefefefef”

Uncomment to disable graphical terminal (grub-pc only)

#GRUB_TERMINAL=console

The resolution used on graphical terminal

note that you can use only modes which your graphic card supports via VBE

you can see them in real GRUB with the command `vbeinfo’

#GRUB_GFXMODE=640x480

Uncomment if you don’t want GRUB to pass “root=UUID=xxx” parameter to Linux

#GRUB_DISABLE_LINUX_UUID=true

Uncomment to disable generation of recovery mode menu entries

#GRUB_DISABLE_RECOVERY=“true”

Uncomment to get a beep at grub start

#GRUB_INIT_TUNE=“480 440 1”

Я удари таа цомада баце lscpu | grep Thread && lscpu | grep CPU && lscpu | grep Core
Use this command and paste output here please lscpu | grep Thread && lscpu | grep CPU && lscpu | grep Core

BR

@ nu11secur1ty, Here you are:

randrianarivelo@latitude:~$ lscpu | grep Thread && lscpu | grep CPU && lscpu | grep Core
Thread(s) per core: 2
CPU op-mode(s): 32-bit, 64-bit
CPU(s): 4
On-line CPU(s) list: 0-3
CPU family: 6
Model name: Intel® Core™ i5 CPU M 560 @ 2.67GHz
CPU MHz: 1404.930
CPU max MHz: 2667.0000
CPU min MHz: 1199.0000
NUMA node0 CPU(s): 0-3
Vulnerability Mds: Vulnerable: Clear CPU buffers attempted, no microcode; SMT vulnerable
Core(s) per socket: 2
Model name: Intel® Core™ i5 CPU M 560 @ 2.67GHz

You could go through your syslog (or whatever it’s called on your distro) and read through it’s early stages of booting, to get some clue as to why your kernel is not bringing up all your CPUs. For example, in my syslog I find…

Sep  1 21:01:16 R-US-IL kernel: smpboot: CPU0: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz (family: 0x6, model: 0x2a, stepping: 0x7)
Sep  1 21:01:16 R-US-IL kernel: rcu: Hierarchical SRCU implementation.
Sep  1 21:01:16 R-US-IL kernel: smp: Bringing up secondary CPUs ...
Sep  1 21:01:16 R-US-IL kernel: x86: Booting SMP configuration:
Sep  1 21:01:16 R-US-IL kernel: .... node  #0, CPUs:      #1
Sep  1 21:01:16 R-US-IL kernel: kvm-clock: cpu 1, msr 21fe041, secondary cpu clock
Sep  1 21:01:16 R-US-IL kernel: #2
Sep  1 21:01:16 R-US-IL kernel: kvm-clock: cpu 2, msr 21fe081, secondary cpu clock
Sep  1 21:01:16 R-US-IL kernel: #3
Sep  1 21:01:16 R-US-IL kernel: kvm-clock: cpu 3, msr 21fe0c1, secondary cpu clock
Sep  1 21:01:16 R-US-IL kernel: smp: Brought up 1 node, 4 CPUs

…so, you see, mine has successfully brought up 4 CPUs.
In your syslog there may be some clues about what’s going wrong.

Also,

cat /proc/cmdline

And…

cat /proc/cpuinfo

And…

uname -a

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