Task Switching is causing kwin_x11 to dump core

I have been using Manjaro for the past 2 years and love it.

Not sure what happened or when it happened, but when i try to switch tasks:

  • I don’t see the task switcher window
  • The window-thumb nails do not show
  • The desktop flashes & I think the window re-render
  • Checking the system logs I see a kwin_x11 dumped core

When I checked the compositor - it was disabled. I enabled it. And still see the same behavior.

If I do tasks switching a couple of times the compositor shutdown as well…and I lose window transparency, etc.

I found several posts (sorry for some reason I cannot include links in my post):

  • [forum.manjaro] kde-plasma-task-switcher-no-longer-renders-window-thumbnails-and-broken-desktop-effects-how-do-i-restore-thumbnails-when-switching-windows-with-global-shortcuts/31369
  • [reddit] enable_to_show_the_thumbnails_for_kde_plasma_task/
  • [forum.manjaro] compositor-not-starting-after-boot-kde/155054

I’ll try to provide you with some logs - but let me know if I can provide more info.

Thank you for your attention!

core-dump

  • Listed in Reverse chronological order
systemd-coredump[2161]: [🡕] Process 1887 (kwin_x11) of user 1000 dumped core.
                                               
                                               Found module linux-vdso.so.1 with build-id: af16c81495e6d30029243d33462c2aee947f771f
                                               Found module libwebp.so.7 with build-id: 87e81472aa7ff3ed1061cfc13d6960dbe00c35ab
                                               Found module libwebpdemux.so.2 with build-id: b7d359c460bcb828b2ab4f34adfa8673af8a657b
                                               Found module libwebpmux.so.3 with build-id: 4e17ff5fa40f00cda51d08d9edd48d442d3044e2
                                               Found module libqwebp.so with build-id: 0aa3bb06c8b9370b0f026c56246f8153fdd5be41
                                               Found module libqwbmp.so with build-id: 3ca3d2ff12c56b6e0f99311277f983e093f112cf
                                               Found module libtiff.so.5 with build-id: e8d89a0fb0847641ddb75c5f03fa89d68155a75d
                                               Found module libqtiff.so with build-id: dda51dc7321967c46c7279ad1b5c142093cc71f8
                                               Found module libqsvg.so with build-id: 329838a55e40bafc041f8f3c10c6f672eca51051
....
Dec 23 09:58:01 name dbus-daemon[1235]: [session uid=1000 pid=1235] Activating service name='org.kde.KSplash' requested by ':1.55' (uid=1000 pid=2159 comm="/usr/bin/kw>
Dec 23 09:58:01 name kwin_x11[2159]: Module 'org.kde.kwin.decoration' does not contain a module identifier directive - it cannot be protected from external registratio>
Dec 23 09:58:00 name kwin_x11[2159]: kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5120:46: this compose sequence is a duplicate of another; skipping >
Dec 23 09:58:00 name kwin_x11[2159]: kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5117:45: this compose sequence is a duplicate of another; skipping >
Dec 23 09:58:00 name kwin_x11[2159]: kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5113:46: this compose sequence is a duplicate of another; skipping >
Dec 23 09:58:00 name kwin_x11[2159]: kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5111:46: this compose sequence is a duplicate of another; skipping >

kernel
I had upgraded to 5.15, but after seeing this issue decided to downgrade to 510 just to be on the safe side. Still see the same problem

> mhwd-kernel -li                                                                                                                                       [CMD]
Currently running: 5.10.84-1-MANJARO (linux510)
The following kernels are installed in your system:
   * linux510

display controllers

 mhwd -li -d
   NAME:        video-nvidia
   ATTACHED:    PCI
   VERSION:     2021.12.18
   INFO:        Closed source NVIDIA drivers for linux.
   PRIORITY:    5
   FREEDRIVER:  false
   DEPENDS:     -
   CONFLICTS:   video*nvidia* 
   CLASSIDS:    0300 0302 
   VENDORIDS:   10de 

system information

System:
  Kernel: 5.10.84-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0
    Desktop: KDE Plasma 5.23.4 tk: Qt 5.15.2 info: latte-dock wm: kwin_x11
    vt: 1 dm: SDDM Distro: Manjaro Linux base: Arch Linux

Graphics:
  Device-1: NVIDIA GP104 [GeForce GTX 1080] vendor: ASUSTeK driver: nvidia
    v: 495.44 alternate: nouveau,nvidia_drm bus-ID: 01:00.0 chip-ID: 10de:1b80
    class-ID: 0300
Display: x11 server: X.Org 1.21.1.2 compositor: kwin_x11 driver:
    loaded: nvidia display-ID: :0 screens: 1

modules

cat /etc/modules-load.d/mhwd-gpu.conf                                                                                                             [CMD]
##
## Generated by mhwd - Manjaro Hardware Detection
##
 
nvidia
nvidia-drm

---------------------------
cat /etc/modprobe.d/mhwd-gpu.conf                                                                                                                     [CMD]
##
## Generated by mhwd - Manjaro Hardware Detection
##
 
blacklist nouveau
blacklist ttm
blacklist drm_kms_helper
blacklist drm

After hours of digging through logs and reading various posts. Out of desperation, I decided to do something seemly stupid. I decided to change the task switcher visualization.

I changed it from Large Icons to Compact

Now everything works. No KWin crashes, and the compositor stays active.

In fact all of the Visualizations seem to work except Large Icons.

I am also seeing a few error lines indicating Icon Themes are not found. I have been using the candy-icons as long as I can remember. But now I wonder maybe these missing icon themes are contributing to the task switcher issue.

Also interesting to note the Small Icon task switcher also works.

Anyway this solution works for me - I am posting it here in case anyone else runs into this issue

Icon theme " breeze" not found.
Icon theme "ubuntu-mono-dark" not found.
Icon theme "Mint-X" not found.
Icon theme "elementary" not found.

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