Bug 454352

Summary: While typing in Krunner opened above Firefox playing a video, Firefox drops almost all frames
Product: [Plasma] krunner Reporter: Lucia Mrenica <lucia.mrenica>
Component: generalAssignee: Alexander Lohnau <alexander.lohnau>
Status: RESOLVED DOWNSTREAM    
Severity: normal CC: lucia.mrenica, nate, plasma-bugs-null
Priority: NOR    
Version First Reported In: 5.24.90   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Lucia Mrenica 2022-05-24 18:12:30 UTC 
STEPS TO REPRODUCE
1. Play a YouTube video (or use any other site - tested with Youtube and Twitch) in Firefox
2. Open Krunner and start typing

OBSERVED RESULT
While you're typing in Krunner, Firefox will drop almost all frames (play the video at ~2 fps).
When you stop typing video playback goes back to normal.

EXPECTED RESULT
Krunner doesn't have an impact on other apps. The CPU usage during this is not high, like it's not 100% even on a single core. This in on Wayland. This report might be a Firefox issue.
Comment 1 Alexander Lohnau 2022-05-24 19:11:46 UTC 
Has activating the normal Kickoff launcher the same effect?
Comment 2 Lucia Mrenica 2022-05-24 19:15:20 UTC 
The normal launcher actually has the same issue, I didn't notice that before. That means the issue is caused by searching for stuff?
Comment 3 Alexander Lohnau 2022-05-24 19:24:14 UTC 
Not sure if the issue is searching for stuff or the launchers showing up.

Do you get the lags when just opening KRunner/Kicker or does typing in them cause the lags? Do you have the video in fullscreen?
Comment 4 Lucia Mrenica 2022-05-24 19:31:30 UTC 
(In reply to Alexander Lohnau from comment #3)
> Not sure if the issue is searching for stuff or the launchers showing up.
> 
> Do you get the lags when just opening KRunner/Kicker or does typing in them
> cause the lags? Do you have the video in fullscreen?

Just opening KRunner/Kicker is OK, opening and closing one or the other quickly is OK, having it open while watching a video is also OK, playing a video in fullscreen or not makes no difference.
Comment 5 Nate Graham 2022-05-25 17:17:54 UTC 
So it only happens when you type?

Is there a spike in CPU activity when the video starts to lag?
Comment 6 Lucia Mrenica 2022-06-04 10:54:18 UTC 
This issue seems to be resolved with FF Beta 102 if GPU video decoding (VAAPI) is enabled.
Comment 7 Nate Graham 2022-06-06 17:34:48 UTC 
Cool, I guess it's an app issue. Might wanna report this to the Firefox devs.