Linux Mint Forums
Forum rules
Before you post please read how to get help. Topics in this forum are automatically closed 6 months after creation.
[SOLVED] One CPU pegged to 100% at idle
Post by agz » Thu Aug 05, 2021 4:00 am
I have freshly installed Linux Mint and after doing some customization one of my CPUs is pegged to 100% at all times. I’ve gone through a few of the topics here and none of them addressed my problem.
The only customizations I’ve done relative to XFCE is I added a few separators and gadgets to the taskbar. Subsequently I removed them yet my CPU usage remains high. I also tried to disable the compositor to no effect. My laptop is getting hot enough to cause concern so I am hoping I find a resolution to this.
Along with the above I also had tried to run
xfconf-query -c xfwm4 -p /general/vblank_mode -t string -s "xpresent" --createSystem: Host: laptop Kernel: 5.4.0-80-generic x86_64 bits: 64 Desktop: Xfce 4.16.0 Distro: Linux Mint 20.2 Uma Machine: Type: Laptop System: LENOVO product: 20HR006JUS v: ThinkPad X1 Carbon 5th serial: Mobo: LENOVO model: 20HR006JUS v: SDK0J40697 WIN serial: UEFI: LENOVO v: N1MET65W (1.50 ) date: 04/19/2021 Graphics: Device-1: Intel HD Graphics 620 driver: i915 v: kernel Display: server: X.Org 1.20.11 driver: modesetting unloaded: fbdev,vesa resolution: 2560x1440~60Hz OpenGL: renderer: Mesa Intel HD Graphics 620 (KBL GT2) v: 4.6 Mesa 21.0.3 Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 3 times in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
SMG Level 24
Posts: 24780 Joined: Sun Jul 26, 2020 6:15 pm Location: USA
Re: One CPU pegged to 100% at idle
Post by SMG » Thu Aug 05, 2021 8:28 am
Welcome to the forum, agz.
I’m not sure why you did not supply the complete inxi output, but I believe the cpu on your computer is new enough that running an updated kernel may help.
Open Update Manager. Select View > Linux Kernels and click Continue. Make sure 5.11 is selected on the left panel and then click the top-most option on the right panel. An «Install» button will appear. Install the kernel and then reboot for it to become active.
If that does not help, please supply the entire output of inxi -Fxxxrz as requested in Section 5 of READ: How To Get Help!.
A woman typing on a laptop with LM20.3 Cinnamon.
Re: One CPU pegged to 100% at idle
Post by agz » Thu Aug 05, 2021 11:26 am
Welcome to the forum, agz.
I’m not sure why you did not supply the complete inxi output, but I believe the cpu on your computer is new enough that running an updated kernel may help.
Open Update Manager. Select View > Linux Kernels and click Continue. Make sure 5.11 is selected on the left panel and then click the top-most option on the right panel. An «Install» button will appear. Install the kernel and then reboot for it to become active.
If that does not help, please supply the entire output of inxi -Fxxxrz as requested in Section 5 of READ: How To Get Help!.
Linux laptop 5.11.0-25-generic #27~20.04.1-Ubuntu SMP Tue Jul 13 17:41:23 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
CPU appears to still be pegged on boot.
Apologies for not reading the rules close enough. Here is the full output:
System: Kernel: 5.11.0-25-generic x86_64 bits: 64 compiler: N/A Desktop: Xfce 4.16.0 tk: Gtk 3.24.20 info: xfce4-panel wm: xfwm4 dm: LightDM 1.30.0 Distro: Linux Mint 20.2 Uma base: Ubuntu 20.04 focal Machine: Type: Laptop System: LENOVO product: 20HR006JUS v: ThinkPad X1 Carbon 5th serial: Chassis: type: 10 serial: Mobo: LENOVO model: 20HR006JUS v: SDK0J40697 WIN serial: UEFI: LENOVO v: N1MET65W (1.50 ) date: 04/19/2021 Battery: ID-1: BAT0 charge: 35.7 Wh condition: 36.8/57.0 Wh (65%) volts: 12.8/11.6 model: LGC 01AV494 type: Li-poly serial: status: Unknown cycles: 392 CPU: Topology: Dual Core model: Intel Core i7-7600U bits: 64 type: MT MCP arch: Amber Lake rev: 9 L2 cache: 4096 KiB flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 23199 Speed: 3500 MHz min/max: 400/3900 MHz Core speeds (MHz): 1: 3500 2: 3498 3: 3471 4: 3480 Graphics: Device-1: Intel HD Graphics 620 vendor: Lenovo ThinkPad X1 Carbon 5th Gen driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:5916 Display: x11 server: X.Org 1.20.11 driver: modesetting unloaded: fbdev,vesa resolution: 2560x1440~60Hz OpenGL: renderer: Mesa Intel HD Graphics 620 (KBL GT2) v: 4.6 Mesa 21.0.3 direct render: Yes Audio: Device-1: Intel Sunrise Point-LP HD Audio vendor: Lenovo ThinkPad X1 Carbon 5th Gen driver: snd_hda_intel v: kernel bus ID: 00:1f.3 chip ID: 8086:9d71 Sound Server: ALSA v: k5.11.0-25-generic Network: Device-1: Intel Ethernet I219-LM vendor: Lenovo driver: e1000e v: kernel port: efa0 bus ID: 00:1f.6 chip ID: 8086:15d7 IF: enp0s31f6 state: down mac: Device-2: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel port: efa0 bus ID: 04:00.0 chip ID: 8086:24fd IF: wlp4s0 state: up mac: Drives: Local Storage: total: 476.94 GiB used: 16.59 GiB (3.5%) ID-1: /dev/nvme0n1 vendor: Samsung model: PM981 NVMe 512GB size: 476.94 GiB speed: 31.6 Gb/s lanes: 4 serial: rev: EXA72D1Q scheme: GPT Partition: ID-1: / size: 466.30 GiB used: 8.14 GiB (1.7%) fs: ext4 dev: /dev/dm-1 ID-2: /boot size: 704.5 MiB used: 312.6 MiB (44.4%) fs: ext4 dev: /dev/nvme0n1p2 ID-3: swap-1 size: 980.0 MiB used: 0 KiB (0.0%) fs: swap dev: /dev/dm-2 Sensors: System Temperatures: cpu: 75.0 C mobo: N/A Fan Speeds (RPM): cpu: 6960 Repos: No active apt repos in: /etc/apt/sources.list Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list 1: deb http://packages.linuxmint.com uma main upstream import backport 2: deb https://la.mirrors.clouvider.net/ubuntu focal main restricted universe multiverse 3: deb https://la.mirrors.clouvider.net/ubuntu focal-updates main restricted universe multiverse 4: deb https://la.mirrors.clouvider.net/ubuntu focal-backports main restricted universe multiverse 5: deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse 6: deb http://archive.canonical.com/ubuntu/ focal partner Active apt repos in: /etc/apt/sources.list.d/sublime-text.list 1: deb https://download.sublimetext.com/ apt/stable/ Info: Processes: 208 Uptime: 3m Memory: 15.39 GiB used: 1.09 GiB (7.1%) Init: systemd v: 245 runlevel: 5 Compilers: gcc: 9.3.0 alt: 9 clang: 10.0.0-4ubuntu1 Shell: bash v: 5.0.17 running in: xfce4-terminal inxi: 3.0.38 from running top it appears `kworker+` is doing the consumption? Second most consuming process is `ksoftir+`.
One CPU core at 100% load
I recently rebooted my PC after a system update and noticed that I have at least one CPU core at 100% load. I tried rebooting but the problem remains. 
The result of the top is shown below : 
Using a core for less than 100% is a waste of resources. You paid for that core why not use it to its fullest? And the generic piece of software to go to is top (and htop ). Please add the results of top to the question. It will list the processes with the heaviest at the top.
The result of the «top» command shows a process «apport» depending on root to be using CPU between 95 and 100 %. Hope this will help you
after a system update (uname -a Linux PC-DE-LDP 4.4.0-36-generic #55~14.04.1-Ubuntu SMP Fri Aug 12 11:49:30 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux) the problem remains. «apport» process taking 86 to 100% cpu
1 Answer 1
I’ve found a way to disable apport to run .
The «apport» process description and usage is apport there
The MOST important drawback of this method is that the «apport» process won’t be able to detect problems and to report them.
Is this drawback not too important compared to seeing the process taking all CPU on one core ?
The document describing the apport process seems to tell that it’s only useful on unstable version and normally set do disabled.
One CPU at 100% at all times
For some reason one of my CPUs is always at 100% usage. Can anyone tell what the problem is from the pictures? 
Thanks
I’ve seen this happen after a blanket font change in an old copy of Librewriter. What version system/Libre office are you running?
1 Answer 1
This happened to me today:
From conky display the process ID is 14633, so in the terminal use:
─────────────────────────────────────────────────────────────────────────────────────────── rick@alien:~/Python$ ps -o ppid=14633 14633 17412 3140 [1]+ Done gedit gmail-list-msg.py ─────────────────────────────────────────────────────────────────────────────────────────── rick@alien:~/Python$ ps -s -p 14633 UID PID PENDING BLOCKED IGNORED CAUGHT STAT TTY TIME COMMAND 0 14633 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000 R ? 9:16 [kworker/4:0] ─────────────────────────────────────────────────────────────────────────────────────────── rick@alien:~/Python$ ps -s -p 3140 UID PID PENDING BLOCKED IGNORED CAUGHT STAT TTY TIME COMMAND 1000 3140 0000000000000000 0000000000000000 0000000000001000 0000000180010000 Sl ? 0:07 /usr/lib/gnome ─────────────────────────────────────────────────────────────────────────────────────────── rick@alien:~/Python$ ps -s -p 17412 UID PID PENDING BLOCKED IGNORED CAUGHT STAT TTY TIME COMMAND 1000 17412 0000000000000000 0000000000010000 0000000000380004 000000004b817efb Ss pts/19 0:00 bash ─────────────────────────────────────────────────────────────────────────────────────────── rick@alien:~/Python$ The 100% CPU usage was caused by using:
gedit is used all the time as a background process and this is the first time I’ve seen 100% usage.
- After closing gedit the offending process: kworker/4:0 is still using 100% of one CPU.
- After closing gnome-terminal the offending process is still using 100% of one CPU.
- After opening a new terminal using sudo kill 14633 doesn’t help.
- After using sudo kill 3140 there is no change.
- Using sudo kill 17412 has no effect.
The only option left is to reboot and monitor if using gedit Xxxx & causes problem to reoccur.
First Reboot
After first reboot the problem shifted from CPU 4 to CPU 0 and offending kworker changed from 4 to 3 .
Gnome terminal was automatically called by Startup Applications which seemed a regression of this bug: Debian Bug report logs — #594245 gnome-terminal using a lot of cpu
I deactivated gnome-terminal from Startup Applications and rebooted
Second Reboot
After second reboot no CPU is running at 100%.
I notice another problem where CPU frequency is running close to maximum of 3,000 MHz when it should be around 1,000 MHz with powersave governor active (which it is).
I also notice a crash report on pstree which is called by one of my bash script daemons that didn’t wake up properly. I filed the automatic data collection bug report with Ubuntu and then rebooted.
Third Reboot
The BIOS start up screen seems frozen. Do a 1 second power button press and it acts like a 10 second power button press (hard power off).
Press power button again for cold boot (no longer a Restart / Warm Boot).
Power up after Shutdown
All is well again. Unknown what exactly went wrong but hopefully the documented steps helps others diagnose transient errors.