Randomly, parts of the screen will start flickering after a window changes its size. It can happen when using partial maximize (horizontal/vertical), and is almost always reproducible when starting a VirtualBox machine or after clicking the “Options »” button in a print window. nvidia gts 450/closed-source drivers/using export __GL_YIELD="USLEEP" Reproducible: Sometimes Steps to Reproduce: 1. Open a window. 2. Make it change its size. 3. Have a seizure.
Try KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace & and please also attach the output of qdbus org.kde.KWin /KWin supportInformation
Created attachment 94680 [details] kwin support info
I tried reproducing with that environment variable and couldn’t do it (but do note it happens randomly). I added it to /etc/profile.d/kwin.sh (along with the usleep workaround) and will try it in the long term. I’ll report back in two days.
Didn’t get any flicker yet… seems like that switch is the way to go. But do I really need two workaround settings just to get a functional environment?
Please don't be pathetic. There's obviously either a bug in the driver or kwin's usage of the feature, but it's required to figure what the problem actually is - "flickers" is not exactly a useful problem description. => Next, enforce "swapping minus front buffer reading" by setting "tearing prevention" to full scene repaints (keep buffer_age usage disabled) => If there's still no problem, re-activate KWIN_USE_BUFFER_AGE (remove/comment the environment or set it to "1") but keep tearing prevention at full scene repaints.
I don’t have time for this.
You'll then have to hope it auto-fixes (eg. with a driver update)