Created attachment 156800 [details] load SUMMARY If I scroll through all open apps on panel, ALL apps that I scroll through start consuming significant amount of CPU (around 10% each). Load drops to zero when all apps idling. It virtually doesn't matter if I use it with KDE apps or not (e.g. I tested with firefox, systemmanager and dolphin open). kwin process also gets some load here too. So I suspect that wayland is the culprit here. And since diverse set of apps starts to behave in a same way I have some doubts that firefox, systemmanager and dolphin all have same bug at the same time. Well, it could be wayland-client bug still but that's out of scope of what I am able to debug. STEPS TO REPRODUCE 1. Open some apps 2. Scroll through tasks rapidly using task applet OBSERVED RESULT Significant CPU usage for all apps involved EXPECTED RESULT Something more moderate I guess? SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.27.1 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 Kernel Version: 6.1.12-zen1-1-zen (64-bit) Graphics Platform: Wayland Graphics Processor: AMD Radeon RX Vega M GL Graphics
When you do this, KWin is rapidly showing and hiding them, and there are animated transitions, shadows, possible transparency and blur, etc. Not sure There's really a bug here. When you ask the system to do something hard, it takes some resources. :)
(In reply to Nate Graham from comment #1) > When you ask the system to do something hard, it > takes some resources. :) I'd agree if only kwin was consuming resources. But it also causes apps to consume quite significant amount of CPU cycles while apps themselves basically not doing any active work. So there's probably something funny going on during interaction between compositor and apps and that is what doesn't seem like a normal thing to me.
I also checked out X11 session and well, if you do this there, CPU usage for all processes is less than 10-12%. From that, Xorg and plasmashell processes consume more than half. So I am pretty sure that this is quite significant issue when same actions now take 5x more CPU time than old times.
Ok, let's see what KWin people have to say about it.