Fast fan

[cliffcoggin]

I recently had a problem with the computer fan inexplicably running fast (see viewtopic.php?f=90&t=350906)
which I thought had been cured, but I was mistaken. As soon as the computer starts, yet is till idle, one of the four cores runs at nearly 100% even though the temperature is ambient and there are no processes running.

I looked in the logs and found this

which means nothing to me. Can anybody assist please?

[powerwagon75]

Hi Cliff,

Don't know if will assist you, but do you have htop installed (terminal-based application)? It appears to give a better real-time accounting of CPU activity. I compared them side by side, and htop showed a lot more CPU activity.

[cliffcoggin]

Thanks. I have just installed htop and will keep an eye on it.

Curiously, the fan slowed to normal speed 40 minutes after writing my query. In that time the computer was idle and nothing showed as being active in System Monitor, so it will be interesting to see what is revealed by htop if and when the fan speed increases again.

[DPM]

You could also check in the system monitor not just looking at your processes, but at all processes, including the system ones. Another thing to check is the date of the last Timeshift snapshot - maybe that's what the computer was doing?

[cliffcoggin]

I was not aware that other settings than 'my processes' existed. That is something else to be investigated.

[Termy]

It's probably software-related.

If, however, it's something you've noticed on every distribution of Linux and in Windows, you might want to see if there's an update (official source only) for your BIOS/UEFI — taking a look at the changelog — maybe especially if you're using a PWM (Pulse-Width Modulation) fan. Refer to your board's official documentation.

WARNING: flashing your BIOS/UEFI can 'brick' your motherboard if done incorrectly.

Are you hardware-savvy at all? If, after testing the software side of things, I decided it could be hardware-related, I'd try different fan pins on the motherboard, to see if it's somehow at fault, a different fan altogether, and lastly, if I suspected a power issue (too much power going to the fan?) I'd test the PSU with one of those testing kits.

Does everything else otherwise work? Have you stress-tested the machine? Linux can run so lightly that you might miss problems which could occur during stress. If you have inexplicable hard crashes, strange behaviours from the system, unusual sounds from your computer, and/or odd new smells coming from your computer, then it ties nicely into my above paragraph.

It might even be solved or worked around simply with a BIOS/UEFI setting.

[cliffcoggin]

I would recognise a fan and maybe a transformer, but apart from that I have no idea what the computer's components look like so no, I am not hardware-savvy. Nevertheless I doubt it is a hardware problem because the computer is about seven years old, Linux Mint 18 then 19 has been on it for four years, yet the fast fan problem has only occurred perhaps three times in the past half year. On those occasions there have been no other unusual physical signs.

Like you I suspect it is to do with software, and until the problem recurs and I can associate it with a particular process, I am at a loss.

[cliffcoggin]

The fast running of the fan during idle operation recurred today, the first time since 17th June. System Monitor revealed it to be caused by kworker/2.2 using 17% CPU and ksoftirqd/2 using 7% CPU. A DDG search showed some explanations, none of which I understood, but it appears to be a harmless phenomenon.

The fan returned to normal speed after half an hour, nevertheless I would welcome an explanation of kworker if it can be put in simple terms.

[motoryzen]

The fast running of the fan during idle operation recurred today, the first time since 17th June. System Monitor revealed it to be caused by kworker/2.2 using 17% CPU and ksoftirqd/2 using 7% CPU. A DDG search showed some explanations, none of which I understood, but it appears to be a harmless phenomenon.

The fan returned to normal speed after half an hour, nevertheless I would welcome an explanation of kworker if it can be put in simple terms.

1. Please post your inxi -Fxxxrz results
2. What all things do you have running upon automatic start up?
3. Kernel version? If it's 5.8 or newer, then I'm willing to doubt the kernel itself is the problem.

A. You can also create cpu backtraces to find out why a kworker is using much cpu muscle. https://www.youtube.com/watch?v=66Gr4XNsScQ skip to 1:35 time in the video explains it more along with the command. ( sounds to me like backtracing your steps to find something you've lost in your house *shrugs* )

B. Perf is a way to analyze what tasks are hogging your cpu at any time. ... same video link but skip to 2:19 . * note..if you got your kernel from Ubuntu mainline kernel installer ( like I did...kernel 5.11.16 etc etc ) you'll probably encounter message talking about "perf not found for kernel *insert kernel name here*" Seems this only recognizes kernels dealt with directly via your distro, in my case..Linux Mint and the newest kernel I've seen is 5.11.0-22, ...thus for one example.....you'd perform the install without quotes "sudo apt install linux-tools-common linux-tools-5.11.0-22-generic" if you have 5.11.0-22 already installed and I think you'll need to be running/booted involving that kernel version for Perf to final work normally and not give that odd error message.

Beyond A and B...i'm not yet sure. Hopefully someone more experienced like SMG, Andy, or another will chime in .

[Petermint]

Have you cleaned your fan? If a 17% busy CPU is pushing your fan enough to hear it, there could be dust making the fan work harder. A clean out might let the fan run slower, to the point where you do not hear it.

[cliffcoggin]

1. Please post your inxi -Fxxxrz results
2. What all things do you have running upon automatic start up?
3. Kernel version? If it's 5.8 or newer, then I'm willing to doubt the kernel itself is the problem.

Code: Select all

System:
  Host: cliffcoggin-System-Product-Name Kernel: 4.15.0-147-generic x86_64 
  bits: 64 compiler: gcc v: 7.5.0 Desktop: Cinnamon 4.2.4 wm: muffin 4.2.2 
  dm: LightDM 1.26.0 Distro: Linux Mint 19.2 Tina base: Ubuntu 18.04 bionic 
Machine:
  Type: Desktop Mobo: ASUSTeK model: M5A78L-M/USB3 v: Rev X.0x 
  serial: <filter> BIOS: American Megatrends v: 1503 date: 11/14/2012 
CPU:
  Topology: Quad Core model: AMD FX-4130 bits: 64 type: MCP arch: Bulldozer 
  rev: 2 L2 cache: 2048 KiB 
  flags: lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 30539 
  Speed: 1475 MHz min/max: 1400/3800 MHz boost: enabled Core speeds (MHz): 
  1: 1594 2: 1423 3: 1413 4: 1509 
Graphics:
  Device-1: AMD RS780L [Radeon 3000] vendor: ASUSTeK driver: radeon 
  v: kernel bus ID: 01:05.0 chip ID: 1002:9616 
  Display: x11 server: X.Org 1.19.6 driver: ati,radeon 
  unloaded: fbdev,modesetting,vesa resolution: 1920x1080~60Hz 
  OpenGL: renderer: AMD RS780 (DRM 2.50.0 / 4.15.0-147-generic LLVM 10.0.0) 
  v: 3.3 Mesa 20.0.8 compat-v: 3.0 direct render: Yes 
Audio:
  Device-1: AMD SBx00 Azalia vendor: ASUSTeK M4A785TD driver: snd_hda_intel 
  v: kernel bus ID: 00:14.2 chip ID: 1002:4383 
  Device-2: AMD RS780 HDMI Audio [Radeon 3000/3100 / HD 3200/3300] 
  vendor: ASUSTeK driver: snd_hda_intel v: kernel bus ID: 01:05.1 
  chip ID: 1002:960f 
  Sound Server: ALSA v: k4.15.0-147-generic 
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: ASUSTeK P8 series driver: r8169 v: 2.3LK-NAPI port: e800 
  bus ID: 04:00.0 chip ID: 10ec:8168 
  IF: enp4s0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
Drives:
  Local Storage: total: 465.77 GiB used: 69.50 GiB (14.9%) 
  ID-1: /dev/sda vendor: Samsung model: SSD 840 EVO 250GB size: 232.89 GiB 
  speed: 3.0 Gb/s serial: <filter> rev: BB6Q scheme: MBR 
  ID-2: /dev/sdb vendor: Samsung model: SSD 850 EVO 250GB size: 232.89 GiB 
  speed: 3.0 Gb/s serial: <filter> rev: 1B6Q scheme: MBR 
Partition:
  ID-1: / size: 21.97 GiB used: 13.06 GiB (59.5%) fs: ext4 dev: /dev/sdb1 
  ID-2: /home size: 194.54 GiB used: 56.44 GiB (29.0%) fs: ext4 
  dev: /dev/sdb3 
  ID-3: swap-1 size: 3.82 GiB used: 0 KiB (0.0%) fs: swap dev: /dev/sdb4 
Sensors:
  System Temperatures: cpu: 34.0 C mobo: 35.0 C 
  Fan Speeds (RPM): cpu: 1934 case-1: 0 
  Voltages: 12v: 12.11 5v: N/A 3.3v: 3.36 vbat: N/A 
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://www.mirrorservice.org/sites/packages.linuxmint.com/packages tina main upstream import backport
  2: deb http://archive.ubuntu.com/ubuntu bionic main restricted universe multiverse
  3: deb http://archive.ubuntu.com/ubuntu bionic-updates main restricted universe multiverse
  4: deb http://archive.ubuntu.com/ubuntu bionic-backports main restricted universe multiverse
  5: deb http://security.ubuntu.com/ubuntu/ bionic-security main restricted universe multiverse
  6: deb http://archive.canonical.com/ubuntu/ bionic partner
Info:
  Processes: 186 Uptime: 18m Memory: 3.59 GiB used: 1.41 GiB (39.2%) 
  Init: systemd v: 237 runlevel: 5 Compilers: gcc: 7.5.0 alt: 7 Shell: bash 
  v: 4.4.20 running in: gnome-terminal inxi: 3.0.32 
cliffcoggin@cliffcoggin-System-Product-Name ~ $ 

Thank you, but the explanation and solutions shown in that video, like all the others I have looked at, are as clear as mud, so I shall not be attempting backtrace or perf. That sort of tinkering by me is certain to end in tears.

The more I think about this, the less convinced I am that there is anything wrong. The problem is rare, it does no harm to the computer, it is self correcting, and it does not interfere with my work. Perhaps I should simply dismiss it as part of normal computer operation.