My system uses only one (1) cpu core

Hello!

I just installed Manjaro XFCE and noticed some very strange CPU behavior. My CPU behaves like a single core. It operates really slow. One of the 8 threads (4 cores) is maxed out and the other 7 partially contribute around 2-3% rare.
I never had this problem with Manjaro KDE or Manjaro Sway.

System:
  Kernel: 6.9.2-1-MANJARO arch: x86_64 bits: 64 compiler: gcc v: 14.1.1
    clocksource: tsc avail: hpet,acpi_pm
    parameters: BOOT_IMAGE=/boot/vmlinuz-6.9-x86_64
    root=UUID=c7f66160-a66c-43b6-a8c4-f002d96e9d3b rw quiet splash
    udev.log_priority=3 mitigations=off
  Desktop: Xfce v: 4.18.1 tk: Gtk v: 3.24.36 wm: xfwm4 v: 4.18.0
    with: plank,xfce4-panel tools: xfce4-screensaver avail: budgie-screensaver
    vt: 7 dm: LightDM v: 1.32.0 Distro: Manjaro base: Arch Linux
Machine:
  Type: Desktop Mobo: Gigabyte model: GA-970A-D3 v: x.x
    serial: <superuser required> uuid: <superuser required> BIOS: Award v: F7
    date: 10/13/2011
CPU:
  Info: model: AMD FX-8120 bits: 64 type: MT MCP arch: Bulldozer level: v2
    built: 2011 process: GF 32nm family: 0x15 (21) model-id: 1 stepping: 2
    microcode: 0x600063E
  Topology: cpus: 1x cores: 4 tpc: 2 threads: 8 smt: enabled cache:
    L1: 384 KiB desc: d-8x16 KiB; i-4x64 KiB L2: 8 MiB desc: 4x2 MiB L3: 8 MiB
    desc: 1x8 MiB
  Speed (MHz): avg: 1400 min/max: 1400/3100 boost: enabled scaling:
    driver: acpi-cpufreq governor: schedutil cores: 1: 1400 2: 1400 3: 1400
    4: 1400 5: 1400 6: 1400 7: 1400 8: 1400 bogomips: 49958
  Flags: avx ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: reg_file_data_sampling status: Not affected
  Type: retbleed status: Vulnerable
  Type: spec_rstack_overflow status: Not affected
  Type: spec_store_bypass status: Vulnerable
  Type: spectre_v1 status: Vulnerable: __user pointer sanitization and
    usercopy barriers only; no swapgs barriers
  Type: spectre_v2 status: Vulnerable; IBPB: disabled; STIBP: disabled;
    PBRSB-eIBRS: Not affected; BHI: Not affected
  Type: srbds status: Not affected
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: AMD Cedar [Radeon HD 5000/6000/7350/8350 Series] vendor: ASUSTeK
    driver: radeon v: kernel alternate: amdgpu arch: TeraScale-2 code: Evergreen
    process: TSMC 32-40nm built: 2009-15 pcie: gen: 2 speed: 5 GT/s lanes: 16
    ports: active: HDMI-A-1 empty: DVI-I-1,VGA-1 bus-ID: 01:00.0
    chip-ID: 1002:68f9 class-ID: 0300 temp: 70.5 C
  Device-2: Logitech Webcam C200 driver: snd-usb-audio,uvcvideo type: USB
    rev: 2.0 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 5-2:3 chip-ID: 046d:0802
    class-ID: 0102 serial: <filter>
  Display: x11 server: X.org v: 1.21.1.13 with: Xwayland v: 24.1.0
    compositor: xfwm4 v: 4.18.0 driver: X: loaded: modesetting
    alternate: fbdev,vesa dri: r600 gpu: radeon display-ID: :0.0
    note: <missing: xdpyinfo/xrandr>
  Monitor-1: HDMI-A-1 model: LG (GoldStar) 2D FHD TV serial: <filter>
    built: 2013 res: 1920x1080 dpi: 96 gamma: 1.2 size: 509x286mm (20.04x11.26")
    diag: 584mm (23") ratio: 16:9 modes: max: 1920x1080 min: 720x400
  API: EGL v: 1.5 hw: drv: amd r600 platforms: device: 0 drv: r600 device: 1
    drv: swrast gbm: drv: kms_swrast surfaceless: drv: r600 x11: drv: r600
    inactive: wayland
  API: OpenGL v: 4.5 vendor: mesa v: 24.0.8-manjaro1.1 glx-v: 1.4
    direct-render: yes renderer: AMD CEDAR (DRM 2.50.0 / 6.9.2-1-MANJARO LLVM
    17.0.6) device-ID: 1002:68f9 memory: 1000 MiB unified: no
Audio:
  Device-1: AMD Cedar HDMI Audio [Radeon HD 5400/6300/7300 Series]
    vendor: ASUSTeK driver: snd_hda_intel v: kernel pcie: gen: 2 speed: 5 GT/s
    lanes: 16 bus-ID: 01:00.1 chip-ID: 1002:aa68 class-ID: 0403
  Device-2: Focusrite-Novation Scarlett 8i6 USB driver: snd-usb-audio
    type: USB rev: 2.0 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 5-1:2
    chip-ID: 1235:8213 class-ID: 0103 serial: <filter>
  Device-3: Logitech Webcam C200 driver: snd-usb-audio,uvcvideo type: USB
    rev: 2.0 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 5-2:3 chip-ID: 046d:0802
    class-ID: 0102 serial: <filter>
  API: ALSA v: k6.9.2-1-MANJARO status: kernel-api with: aoss
    type: oss-emulator tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.0.7 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
    vendor: Gigabyte driver: r8169 v: kernel pcie: gen: 1 speed: 2.5 GT/s
    lanes: 1 port: ce00 bus-ID: 03:00.0 chip-ID: 10ec:8168 class-ID: 0200
  IF: enp3s0 state: up speed: 100 Mbps duplex: full mac: <filter>
  Info: services: NetworkManager,systemd-timesyncd
Drives:
  Local Storage: total: 1.08 TiB used: 20.5 GiB (1.9%)
  SMART Message: Required tool smartctl not installed. Check --recommends
  ID-1: /dev/sda maj-min: 8:0 vendor: Seagate model: ST1000DM003-9YN162
    size: 931.51 GiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
    tech: HDD rpm: 7200 serial: <filter> fw-rev: CC4C scheme: MBR
  ID-2: /dev/sdb maj-min: 8:16 vendor: OCZ model: AGILITY3 size: 111.79 GiB
    block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s tech: SSD
    serial: <filter> fw-rev: 2.15 scheme: GPT
  ID-3: /dev/sdc maj-min: 8:32 vendor: Kingston model: DataTraveler 3.0
    size: 28.9 GiB block-size: physical: 512 B logical: 512 B type: USB rev: 2.1
    spd: 480 Mb/s lanes: 1 mode: 2.0 tech: N/A serial: <filter> fw-rev: PMAP
    scheme: MBR
  ID-4: /dev/sdd maj-min: 8:48 model: USB DISK 3.0 size: 28.91 GiB
    block-size: physical: 512 B logical: 512 B type: USB rev: 2.1 spd: 480 Mb/s
    lanes: 1 mode: 2.0 tech: N/A serial: <filter> fw-rev: PMAP scheme: MBR
Partition:
  ID-1: / raw-size: 75.21 GiB size: 73.47 GiB (97.70%) used: 20.5 GiB (27.9%)
    fs: ext4 dev: /dev/sda4 maj-min: 8:4
Swap:
  Alert: No swap data was found.
Sensors:
  System Temperatures: cpu: 36.4 C mobo: N/A gpu: radeon temp: 70.5 C
  Fan Speeds (rpm): N/A
Info:
  Memory: total: 8 GiB available: 7.74 GiB used: 1.67 GiB (21.6%)
  Processes: 241 Power: uptime: 6m states: freeze,mem,disk suspend: deep
    avail: s2idle wakeups: 0 hibernate: platform avail: shutdown, reboot,
    suspend, test_resume image: 3.08 GiB services: upowerd,xfce4-power-manager
    Init: systemd v: 255 default: graphical tool: systemctl
  Packages: pm: pacman pkgs: 1283 libs: 357 tools: pamac Compilers:
    clang: 17.0.6 gcc: 14.1.1 Shell: Bash v: 5.2.26 running-in: xfce4-terminal
    inxi: 3.3.34

Hello,

Might want to check BIOS settings if has the CPU Core Control set to manual, and probably only one core active.

I would suggest using a LTS kernel instead - 6.6.x or 6.1.x for example.

This mobo seems to have some newer BIOS version available

On the other hand, this seems to report correctly all cores

1 Like

If the result you experience is during a custom package build you may want to check your ~/.makepkg.conf - set the number of cores uses by the process.

If the result is seen running a python program - python is single threaded - and the behaviour is expected.

3 Likes

All of his cores are working — he said so himself… :point_down:

So the thread title is misleading. He simply has a stuck process, or — as @linux-aarhus pointed out — a very demanding single-threaded process.

When I play chess in knights against the computer with gnuchess as the opponent, then I also get one core maxing out whenever gnuchess is consulting its arsenal of tricks. :man_shrugging:

2 Likes

It is not a specific application. It feels like a kernel error or something. The system boot time is slow and the speed drops dramatically after LightDM. The screenshot is while running a firefox (installed with pamac install firefox) playing a youtube video.

The good thing is that I tested on bare metal that ManjaroXFCE can actually run on a single core machine! :sweat_smile:

I would suggest using a LTS kernel instead - 6.6.x or 6.1.x for example.

That was a really good idea and solved my issue!
I thought Manjaro had the LTS Kernel as default and never checked.
Thanx.

1 Like

This topic was automatically closed 36 hours after the last reply. New replies are no longer allowed.