Bug 451007 - High CPU usage and laggy scrolling in Discover while loading app page
Summary: High CPU usage and laggy scrolling in Discover while loading app page
Status: RESOLVED DUPLICATE of bug 448784
Alias: None
Product: Discover
Classification: Applications
Component: discover (show other bugs)
Version: unspecified
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: Dan Leinir Turthra Jensen
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-03-01 18:08 UTC by guimarcalsilva
Modified: 2022-03-22 02:04 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:


Attachments
Laggy scroll even on 6 Core desktop CPU (3.66 MB, video/mp4)
2022-03-01 18:08 UTC, guimarcalsilva
Details

Note You need to log in before you can comment on or make changes to this bug.
Description guimarcalsilva 2022-03-01 18:08:46 UTC
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
Comment 1 Nate Graham 2022-03-22 01:45:36 UTC
Almost certainly Bug 448784.

*** This bug has been marked as a duplicate of bug 448784 ***
Comment 2 guimarcalsilva 2022-03-22 01:50:22 UTC
(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.
Comment 3 Nate Graham 2022-03-22 02:04:53 UTC
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.