Welcome to our peer-to-peer forums, where owners help owners. Need help now? Visit eSupport here.

English Community

Linux Operating SystemsOther Linux Discussions
All Forum Topics
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186
  • Message 1 of 22

High CPU Usage On ThinkPad T480

2020-07-25, 23:56 PM

I have a severe issue where the ThinkPad T480 has high CPU usage on a single CPU core, which is caused by the kworker process. This started after using the 5.4.0-40 Linux kernel (was previously using version 5.3.0-45 which doesn't have the issue). Have been using suspend/resume as a temporary workaround which works (in most cases) until the laptop is started or rebooted again. Currently using Linux kernel 5.40.0-42 which doesn't resolve the issue unfortunately. Attached to this post is a Linux kernel stack trace which shows that the issue is caused by ACPI (power management), which might be related to the laptop's system firmware.

Reply
Answer
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186

Re:High CPU Usage On ThinkPad T480

2020-08-11, 23:41 PM

Updating the System firmware to 1.34 has fixed the issue.

Reply

Replies(21)
Options

7 Posts

08-01-2018

United States of America

8 Signins

97 Page Views

  • Posts: 7
  • Registered: ‎08-01-2018
  • Location: United States of America
  • Views: 97
  • Message 2 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-26, 10:15 AM

maybe related to this ?  https://forums.lenovo.com/t5/Other-Linux-Discussions/T480-dGPU-throttles-at-80C-also-VBIOS-version-question/m-p/5023943

 

https://github.com/erpalma/throttled

Reply
Options

236 Posts

12-17-2018

United States of America

380 Signins

2486 Page Views

  • Posts: 236
  • Registered: ‎12-17-2018
  • Location: United States of America
  • Views: 2486
  • Message 3 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-27, 11:11 AM

Based on your stack trace the version of BIOS you have is very old, there have been many fixes added for this type of thing so please update to the current version to see if that addresses this issue.  Any attempt to diagnose something that old is impractical

Reply
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186
  • Message 4 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-29, 22:40 PM

Did an update of the system firmware, along with other updates which include Intel ME, Intel Thunderbolt firmware, and some others. The newer version of the system firmware hasn't resolved the issue. Looks increasingly likely that the system firmware is causing the issue.

Reply
Options

15 Posts

06-24-2020

United States of America

21 Signins

130 Page Views

  • Posts: 15
  • Registered: ‎06-24-2020
  • Location: United States of America
  • Views: 130
  • Message 5 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 1:16 AM

@ digiPixel wrote:
 

 

Did an update of the system firmware, along with other updates which include Intel ME, Intel Thunderbolt firmware, and some others. The newer version of the system firmware hasn't resolved the issue.

 

I have not seen this issue on my t480 w/NVIDIA on Fedora.

 

Based on https://www.reddit.com/r/Fedora/comments/hmmnfb/high_cpu_usage_by_kworker_kacpid_on_fedora_32/ and https://forum.manjaro.org/t/solved-kworker-has-100-cpu-usage/7935/3

 

It appears that some hardware is flooding the CPU with interrupts.  In the reddit thread they mention the GPU as the cause for one person and the Manjaro it's a caddy adapter.

 

Are you seeing the issue with the t480 when it's not connected to any peripherals?  Did you change any of the hardware components on the t480?  Also if you still have Windows, are you seeing a similar issue there?

 

The workaround is described here:

https://asdasd.page/2020/01/08/Solution-to-kacpid-high-CPU-usage/

 

Reply
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186
  • Message 6 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 3:32 AM

Integrated graphics hardware (Intel UHD Graphics 620) is used on the ThinkPad T480. The laptop doesn't have a dedicated GPU. All the mentioned links point to a laptop using dedicated NVidia graphics hardware which isn't relevant.

Reply
Options

15 Posts

06-24-2020

United States of America

21 Signins

130 Page Views

  • Posts: 15
  • Registered: ‎06-24-2020
  • Location: United States of America
  • Views: 130
  • Message 7 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 3:36 AM
oh maybe you can use powertop to figure out what's causing the interrupts.
Reply
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186
  • Message 8 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 3:38 AM
IvanW - Which version of the Linux Kernel are you using?
Reply
Options

21 Posts

02-25-2019

New Zealand

20 Signins

186 Page Views

  • Posts: 21
  • Registered: ‎02-25-2019
  • Location: New Zealand
  • Views: 186
  • Message 9 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 4:19 AM

Below is some sample output from powertop:

 

Summary: 446.1 wakeups/second,  0.0 GPU ops/seconds, 0.0 VFS ops/sec and 7.1% CP

 

Power est.              Usage       Events/s    Category       Description

 500 mW    100.0%                      Device         Audio codec hwC0D0: Realt

 248 mW      0.9 ms/s      62.4        Timer          tick_sched_timer

 248 mW      7.5 ms/s      59.8        Process        [PID 12863] /opt/idea-IC-

 185 mW      7.3 ms/s      40.7        Process        [PID 16842] /usr/libexec/

 121 mW      8.4 ms/s      24.4        Process        [PID 895] /usr/lib/xorg/X

 106 mW      7.6 ms/s      23.9        Process        [PID 14076] /opt/brave.co

82.0 mW      1.8 ms/s      20.0        Process        [PID 12855] /opt/idea-IC-

80.4 mW      1.0 ms/s      19.9        Process        [PID 12985] /opt/idea-IC-

80.4 mW      1.0 ms/s      19.9        Process        [PID 12816] /opt/idea-IC-

77.1 mW      4.1 ms/s      17.9        Process        [PID 6320] /opt/brave.com

48.6 mW      1.2 ms/s      11.8        Process        [PID 745] /usr/sbin/acpid

46.5 mW     66.6 µs/s      11.7        kWork          console_callback

46.2 mW    284.1 µs/s      11.6        Process        [PID 778] /lib/systemd/sy

46.1 mW      1.8 ms/s      11.0        Process        [PID 6283] /opt/brave.com

45.4 mW    190.4 µs/s      11.4        Process        [PID 11] [rcu_sched]

44.6 mW      2.7 ms/s       9.2        Process        [PID 1969] cinnamon --rep

35.6 mW     86.1 µs/s       9.0        kWork          psi_avgs_work

 

 

Currently the highest power usage comes from the audio hardware, followed by tick_sched_timer. Cinnamon has the second lowest power usage, with psi_avgs_work (related to kworker) having the lowest power usage.

Reply
Options

15 Posts

06-24-2020

United States of America

21 Signins

130 Page Views

  • Posts: 15
  • Registered: ‎06-24-2020
  • Location: United States of America
  • Views: 130
  • Message 10 of 22

Re:High CPU Usage On ThinkPad T480

2020-07-30, 9:12 AM
I'm using kernel 5.7.10
Reply
Forum Home

Community Guidelines

Please review our Guidelines before posting.

Learn More

Check out current deals!

Go Shop
X

Save

X

Delete

X

No, I don’t want to share ideas Yes, I agree to these terms