Bug 493142

I'd like to add that its very hard to recover from this state, as its not possible to switch to a different tty and kill the process or restart display manager service. It's only possible to recover by ssh-ing into the machine and kill the kwin_wayland process from there.

I'm not able to reproduce this on 6.1.5 or git-master
I started Firefox using a profile with no addons or modifications and verified wayland was listed in about:support - Window Protocol
I loaded https://www.openstreetmap.org/edit and zoomed in and out multiple times.

https://dopravniinfo.cz/ doesn't load at all in the browser, the site times out

I'll leave this open so that someone more knowledgeable about what the cause might be can add a comment

Can _not_ reproduce it as well on Fedora 40 with Plasma 6.2.0 and FF 131 on Wayland.

Nor can I.

Created attachment 175059 [details]
Backtraces of thread from gdb

I was avoiding openstreetmap.org/edit but to test its still an issue I went to the editor and got a crash again. I've pulled a backtrace and a core dump, however core is 2.8GB so not attachable to the bug report.

Thanks for attaching the backtrace. Unfortunately the backtrace is incomplete and missing debug symbols for the following lines that we need to figure out exactly what's going wrong:

#2  0x00007fa17626899f in ??? () at /usr/lib64/libkwin.so.6
#7  0x00007fa172ae3863 in ??? () at /usr/lib64/libQt6Core.so.6

Could you please install debug symbols and attach a new symbolicated backtrace generated by using `coredumpctl gdb` in a terminal window? If necessary, see https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl for details about how to do this. Thanks again!

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Created attachment 175092 [details]
Thread backtraces with qt6 and kwin debug symbols

I've recompiled qt6 core and kwin in order to produce debug symbols. I've also tried to do the same for mesa however the build is failing - I will pursue if it ends up being necessary as well.
I've also noticed I have -O3 enabled, I can try disabling that seems relevant.

Thanks for the updated backtrace.

This is still an issues as of:
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.7.0
Qt Version: 6.7.3

Firefox 134.0b10 (64-bit)

I wish I knew how to get at further info to track this down.

I don't believe 440386 is related, because symptom of this bug is also high memory usage.

Still issue as of:
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.3
Kernel Version: 6.12.28 (64-bit)
Graphics Platform: Wayland
Processors: 8 × 11th Gen Intel® Core™ i7-1165G7 @ 2.80GHz
Memory: 15.4 GiB of RAM
Graphics Processor: Intel® Iris® Xe Graphics

Just noting another configuration, I can't reproduce with Plasma built from git master on Fedora KDE 42, with an NVIDIA graphics card.

Just had another one zooming in on mapy.com . Kwin process on 100% and memory usage rising.

Just on the chance that it changes something - do the following steps within Firefox change anything about the issue on your device?

* Go to about:config
* Set widget.wayland.vsync.enabled to false
* Restart Firefox

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

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

Setting widget.wayland.vsync.enabled to false doesn't prevent this situation from happening.
Might as well confirm versions:

Firefox: 141.0b6 (64-bit)
Operating System: Gentoo Linux 2.17
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.1
Kernel Version: 6.12.34 (64-bit)
Graphics Platform: Wayland

There have been some improvements that might help. Can you update to Plasma 6.4.2 and see if the problem still happens?

Unless it's now fixed in 6.4.2 for your, I believe it would make sense to get some profiling with https://github.com/KDAB/hotspot?tab=readme-ov-file#using

You would record the kwin_wayland process with perf, while it's consuming 100% cpu and study afterwards the flamegraph in hotspot, to see, where it consumes most cycles. Hopefully, this would give a good clue.

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

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

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.

Waited for distro to bump versions.
This is still an issue as of:

Firefox 145.0b9 (64-bit)

Operating System: Gentoo Linux 2.18
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.3
Kernel Version: 6.12.54 (64-bit)
Graphics Platform: Wayland
Processors: 8 × 11th Gen Intel® Core™ i7-1165G7 @ 2.80GHz
Memory: 16 GiB of RAM (15.4 GiB usable)
Graphics Processor: Intel® Iris® Xe Graphics
Manufacturer: Dell Inc.
Product Name: XPS 13 9305