Bug 421014

Summary: Plasma shell suddenly freezes
Product: [Plasma] plasmashell Reporter: DaCoEx <dacoex>
Component: System Monitor widgetsAssignee: Marco Martin <notmart>
Status: RESOLVED WORKSFORME    
Severity: normal CC: nate, noahadvs, plasma-bugs-null
Priority: NOR    
Version First Reported In: 5.18.4   
Target Milestone: 1.0   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description DaCoEx 2020-05-04 17:58:11 UTC 
SUMMARY
Plasma Shell pushes 1 out of 4 CPUs up to 100%
This slows the system down & blocks interactions with Plasma

STEPS TO REPRODUCE
1. Use the computer
2. open typical programs like Thunderbird, Firefox
3. switch different applications

OBSERVED RESULT
1. it slows down and down
2. especially switching between different windows takes a lot of time
3. any interaction with the Plasma Shell components (Application Menu, Editing Panels, Switching Windows) has a lag and takes time
4. The following command solves the problem:
killall plasmashell ; plasmashell
Source:
https://www.reddit.com/r/kde/comments/6leps0/plasmashell_consumes_all_cpu/djt7xdv/

Problem: This also kills non-qt programs like Thunderbird and Firefox.

EXPECTED RESULT
1. Seamless operation

SOFTWARE/OS VERSIONS

Operating System: Kubuntu 20.04
KDE Plasma Version: 5.18.4
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Kernel Version: 5.4.0-28-generic
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-5300U CPU @ 2.30GHz
Memory: 15,5 GiB of RAM

ADDITIONAL INFORMATION

ps -Ao comm,pcpu,cpuid,%mem --sort=-pcpu | head -n 10
COMMAND         %CPU CPUID %MEM
plasmashell     61.2     2  2.4
ksysguard       21.4     1  0.8
firefox         15.9     0  7.5
ksysguardd      15.5     0  0.1
thunderbird      8.7     0  4.0
Web Content      3.5     0  3.9
htop             3.1     0  0.0
Xorg             2.8     0  2.8
chrome           2.6     1  3.7

==> no idea how to show that CPU 4 is at 100%
Ksysguard does not show how each process is distributed along different processes.
Comment 1 DaCoEx 2020-05-04 18:34:48 UTC 
It seems that removing the following from the bottom panel relaxes the situation:

System Load Viewer
X-KDE-PluginInfo-Name=org.kde.plasma.systemloadviewer
X-KDE-PluginInfo-Website=https://kde.org/plasma-desktop/

and perhaps also:

Fokus
https://store.kde.org/p/1308861

==> I hope this sames some people valueable lifetime instead of waiting for plasma to respond.
Comment 2 Nate Graham 2020-05-07 14:51:53 UTC 
How ironic that monitoring the system's performance destroys the system's performance. :/
Comment 3 Noah Davis 2023-08-02 22:17:10 UTC 
Can you still reproduce this issue with the latest version of Plasma? I cannot reproduce this or do not have enough info to do so.
Comment 4 Bug Janitor Service 2023-08-17 03:45:13 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 5 Bug Janitor Service 2023-09-01 03:45:33 UTC 
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!