Bug 489328 - The CPU consumption of the `plasmashell` and `kwin_wayland` processes become stuck when switching through Virtual Desktops
Summary: The CPU consumption of the `plasmashell` and `kwin_wayland` processes become ...
Status: RESOLVED DUPLICATE of bug 487895
Alias: None
Product: plasmashell
Classification: Plasma
Component: Panel (show other bugs)
Version: 6.0.5
Platform: NixOS Linux
: NOR grave
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-27 16:56 UTC by Martin C.
Modified: 2024-06-27 20:55 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Top showing the processes steady high CPU consumption (53.93 KB, image/png)
2024-06-27 16:56 UTC, Martin C.
Details

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Description Martin C. 2024-06-27 16:56:18 UTC
Created attachment 171095 [details]
Top showing the processes steady high CPU consumption

SUMMARY
When the main panel is hidden using the Auto-hide feature, and I switch through virtual desktops, the `plasmashell` and `kwin_wayland` processes become stuck, consuming a considerable amount of CPU cycles; please check the attached screenshot.

STEPS TO REPRODUCE
1. Set the default panel to auto-hide
2. Switch to a different virtual desktop
3. Open the wonderful Konsole or Yakuake terminal emulators and check the mentioned processes' CPU consumption, i.e., with `top`

OBSERVED RESULT
There is an (expected?) spike in the CPU consumption when switching to another virtual desktop; however, the high consumption gets stuck instead of eventually going down

EXPECTED RESULT
The CPU usage spike goes down moments after switching to another virtual desktop

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: NixOS and openSUSE Tumbleweed
(available in About System)
KDE Plasma Version: 6.0.5 on Wayland
KDE Frameworks Version: 6.2.0
Qt Version: 6.7.1

ADDITIONAL INFORMATION
- GPU: Intel TigerLake-LP GT2 [Iris Xe Graphics]
- Driver: i915
- I can reproduce this issue on a live openSUSE Tumbleweed session
- I can't reproduce the issue with the 'Dodge Windows' setting enabled

HTH!
Comment 1 Martin C. 2024-06-27 17:14:35 UTC
Dang! With the "Dodge Windows" feature enabled, I found that the same thing happens when the panel is hidden and I switch virtual desktops.

Something odd, though, is that when I launch Spectacle to take a screenshot of the processes' CPU consumption, it immediately drops to the expected levels.
Comment 2 Reinier 2024-06-27 17:29:47 UTC
Temporarily removing the pager from the panel helps as a workaround, but there are other ways to trigger this bug. Maybe you can help find them all.

*** This bug has been marked as a duplicate of bug 487895 ***
Comment 3 Martin C. 2024-06-27 17:32:55 UTC
Hi Reiner, that's good to know. I will remove the pager then and see if the issue surfaces again.

Since you marked this bug as a duplicate, should I close it to reduce noise and continue the conversation at https://bugs.kde.org/show_bug.cgi?id=487895?
Comment 4 Reinier 2024-06-27 20:55:21 UTC
It's best to continue the conversation in the other thread, but I will leave to one of the devs to close this one.