[Linux] core 가 하나만 인식될 때

$ lscpu Architecture:          x86_64 CPU op-mode(s):        32-bit, 64-bit Byte Order:            Little Endian CPU(s):                48 On-line CPU(s) list:   0-47 Thread(s) per core:    2 Core(s) per socket:    12 Socket(s):             2 NUMA node(s):          2 Vendor ID:             GenuineIntel CPU family:            6 Model:                 85 Model name:            Intel(R) Xeon(R) Gold 5118 CPU @ 2.30GHz Stepping:              4 CPU MHz:               2294.708 BogoMIPS:              4590.73 Virtualization:        VT-x L1d cache:             32K L1i cache:             32K L2 cache:              1024K L3 cache:              16896K NUMA node0 CPU(s):     0,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46 NUMA node1 CPU(s):     1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47 Flags:                 fpu vme de pse ....

 

$ 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_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=2 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="apm=off consoleblank=0" # GRUB_CMDLINE_LINUX_DEFAULT="acpi=off apm=off consoleblank=0" 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"

 

$ sudo update-grub

 

권한 sudo gedit /etc/default/grub   변경한 후에 sudo update-grub  내부적으로 grub-mkconfig 명령이 실행되어... /boot/grub/grub.cfg가 변경

 

커널이 SMP 를 지원해야 한다 uname -a 로 해서 보면 Linux SERVERNAME 2.6.32-41-generic #90-Ubuntu SMP Tue May 22 11:31:25 UTC 2012 i686 GNU/Linux Linux SERVERNAME 4.4.0-173-generic #203-Ubuntu SMP Wed Jan 15 02:55:01 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

 

 

Trouble shooting 

/usr/bin/ld: cannot find -lcrypto
collect2: ld returned 1 exit status

> sudo apt-get install libssl-dev

 

// TODO : acpi smp 
https://elinux.org/images/4/43/Understanding_And_Using_SMP_Multicore_Processors_Anderson.pdf

 

참고:  https://askubuntu.com/questions/127815/using-quad-core-but-only-1-cpu-entry-in-proc-cpuinfo-is-smp-running-on-my-c

 

 

linux core 리눅스 코어 개수 ubuntu multi core issue only one core smp
쿼드코어 사용중인데 우분투에서 제대로 인식되지 않습니다.
Using quad core, but only 1 CPU entry in `/proc/cpuinfo`? Is SMP running on my computer?
Ubuntu sees only 1 core instead of 4
Kernel not detecting multicore cpu 
missing