Frozen Windows on wayland

Help
1

Hey guys,

I don’t really know in which direction to go when it comes to debugging the problem so I thought let’s get some creative input.

The problem:

When a single application has many windows (and/or tabs) some windows become stuck and unresponsive.
However, sometimes they unfreeze after another window of the application responds and gets focus once. If one window is frozen then usually all other windows are frozen too except one, yet sometimes all windows are frozen.

Happened with

chromium-common/stable-security,now 137.0.7151.119-1~deb12u1 amd64 [installed,automatic]
firefox-esr/mozilla,now 140.0esr~build1 amd64 [installed,automatic]
firefox/mozilla,now 140.0~build1 amd64 [installed]

I don’t know the treshold (100 windows, 100 tabs, heavy windows, etc.). My feeling is at like maybe 20 windows/tabs.

my installation:

Debian 6.1.140-1 (2025-05-22) x86_64 GNU/Linux
kde-plasma-desktop/stable,now 5:142 amd64 [installed,automatic]
wayland
nvidia-driver/stable,now 535.247.01-1~deb12u1 amd64 [installed]

Given that the problem only occurs when there are enough windows, my first instinct was ressources (like e.g. when the window is recovered from swap), but my system doesn’t use swap. I couldn’t monitor any ressource problem when it comes to hardware. The rest of the system runs fine (it’s only the particular application).

I tried to switch to x11 session and I think the problem doesn’t occur here — but hard to say because the x11 performance with my installation (nvidia in particular) is so terrible that I can’t run a productive x11 session. A blank simulation (“open 100 windows”) won’t always produce the problem (even in the wayland session).

journalctl -xe lists these funny entries:

plasmashell[3139]: qt.qpa.wayland: Wayland does not support QWindow::requestActivate()

Whenever the problem occurs this log entry is in close proximity (regarding time), but these log entries also appear when the problem doesn’t occur.

My gut tells me it’s a wayland bottleneck but I don’t know how to go further.

Anyone ideas which log to monitor or where to go?

TLDR: how to debug another wayland problem?

2

Well in Debian stable you are using KDE plasma 5.27 that wouldn’t get a fix for such issues, because it is not supported anymore and debian does do maintenance releases.

Next Debian stable that will bring KDE Plasma 6 is about to release.

Your issues sounds like something that would not occur in newer versions.

plasmashell[3139]: qt.qpa.wayland: Wayland does not support QWindow::requestActivate()

Those are unrelated. That’s just some applications weren’t fully ported to Wayland (to be precise the xdg-activitation wayland protocol).

3

thank you for the feedback regarding the log entries.

Well in Debian stable you are using KDE plasma 5.27 that wouldn’t get a fix for such issues, because it is not supported anymore and debian does do maintenance releases.

I figured as much. It’s such a stupid catch 42. I need a stable system (I use the system for my law firm) so debian is the obvious choice but then debian is full of old packages that aren’t supported by the package itself (like plasma). I have so many problems with wayland because of this, it’s nuts

Your issues sounds like something that would not occur in newer versions.

I guess I’ll have to go unstable after all

4

You can stick to X11 for the time being, you will simply have a different set of bugs :smiley:

Debian 13 Trixie isn’t far off.

5

You can stick to X11

I already tried but the performance overall is just garbage. Apparently, the current debian nvidia-driver doesn’t work so well under x11 — damned if you do damned if you don’t.

This whole wayland situation is just another systemd. I see so many posts (not just here) with migration problems. I hope that one day we’ve put it behind us