https://bugs.kde.org/show_bug.cgi?id=442386
--- Comment #2 from C. Leu <k...@bluewin.ch> --- Thanks Vlad Zahorodnii for your replay. I have now switched in kwin the compositing of all my Kubuntu 20.04 LTS installations to OpenGL ES / EGL and noticed so far no issues regarding any sort of stuttering. Maybe I will see a "buffer swap" problem sometimes in the future... ;-) How can I provoke it? Furthermore I enabled the X11 EGL option even in Firefox, - also here no issues so far just a benefit in the overall behavior. However, it could be possible that this problem described here is not only a "GLX" problem but also one of the "notification system". As mentioned, the message "kworker blocked for more than 120 seconds" has not occurred so far with EGL backend enabled. But when the RAM memory is quite full, then I have sometimes still some "hangers" for example in Dolphin. So I decided to disable the notifications completely, only the critical ones are allowed. After this setting there were no more hangers present, - strange but interesting. Whatever, it should be noted that this problem may be primary relevant for systems with low RAM memory. My iMac 5,2 has just 4GB physical RAM installed, but Apple enables in legacy CSM Bios mode only around 3GB which is effectively too less for Kubuntu 20.04 LTS. Apple furthermore also screws down the speed of the SATA controller to UDMA133, which is just ridiculous because it limits totally my Crucial MX200 SSD. These points can be only resolved thorough a installation of Kubuntu in native (mixed-mode) EFI. Whatever, back to the original matter. As for now I have switched to the EGL backend at the following Apple computer models. I noticed an improvement in the KDE GUI behavior at all of them. iMac5,1 (4GB RAM, only 3GB usable, R300 Mesa 21.0.3) iMac8.1 (6GB RAM, native EFI, R600 Mesa 21.0.3) iMac9,1 (8GB RAM, native EFI, R600 Mesa 21.0.3) -- You are receiving this mail because: You are watching all bug changes.
