Created attachment 147219 [details] Laggy scroll even on 6 Core desktop CPU SUMMARY After you click on an app to show its page, scrolling in Discover feels very laggy, scrolling at about 2 to 3 fps even on a 6 core CPU. This lasts until the app page loads completely. This is especially obvious after the new layout changes to the app page. Check the attached video for CPU stats. A user will naturally click on apps and scroll to browse for new ones, so this bug is something that will affect many people if it hits 5.25 stable, especially on less powerful computers. STEPS TO REPRODUCE 1. Open Discover 2. Click on Applications 3. Click on one app in the main list (depending on the number of images or info on the app page the slowness might last longer) 4. While images and comments are loading, scroll OBSERVED RESULT Scrolling feels very laggy and the CPU usage is high EXPECTED RESULT Smooth scrolling Operating System: KDE neon Unstable Edition KDE Plasma Version: 5.24.80 KDE Frameworks Version: 5.92.0 Qt Version: 5.15.3 Kernel Version: 5.13.0-30-generic (64-bit) Graphics Platform: Wayland Processors: 6 × Intel® Core™ i5-9400F CPU @ 2.90GHz Memory: 7,6 GiB of RAM Graphics Processor: Radeon RX 570 Series
Almost certainly Bug 448784. *** This bug has been marked as a duplicate of bug 448784 ***
(In reply to Nate Graham from comment #1) > Almost certainly Bug 448784. > > *** This bug has been marked as a duplicate of bug 448784 *** Is it really? Discover doesn't crash, it just gets temporary slow while the app page is loading.
Yeah, the binding loop means that the QML engine stutters while it figures it out. Sometimes it fails, which leads to a hang. When it succeeds, the result is slowness while loading.