Bug 370179 - UnrealEngine 4 Editor popups cause the ui to lag with kwin_x11
Summary: UnrealEngine 4 Editor popups cause the ui to lag with kwin_x11
Status: RESOLVED NOT A BUG
Alias: None
Product: kwin
Classification: Plasma
Component: general (show other bugs)
Version: 5.8.0
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL: https://www.youtube.com/watch?v=0IBzB...
Keywords:
Depends on:
Blocks:
 
Reported: 2016-10-06 06:38 UTC by salamanderrake
Modified: 2016-10-07 15:04 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


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Description salamanderrake 2016-10-06 06:38:47 UTC
Using UE4Editor( UnrealEngine 4 Editor) with the pop-ups smearing and sever lag in the node(blueprints) editor window.

Reproducible: Always

Steps to Reproduce:
1. Build Editor
2. Run Editor
3. Hover over items to get pop up, and drag variables from the left pane onto the blueprint region and watch it lag.

Actual Results:  
Pop-ups and dragged objects cause sever lag in the UI.

Expected Results:  
Pop-ups come and go with no issue, no UI lag in the editor.
Comment 1 Martin Flöser 2016-10-06 06:41:44 UTC
Please provide output of:
qdbus org.kde.KWin /KWin supportInformation

when the problem is visible.
Comment 3 Christoph Feck 2016-10-07 02:19:41 UTC
If you can provide the information in requested in comment #1, please add it.
Comment 4 salamanderrake 2016-10-07 02:28:45 UTC
This is before UE4Editor starts:
https://gist.github.com/salamanderrake/319407e000873a944dea19ddaede5e24

This is after UE4Editor starts:
https://gist.github.com/salamanderrake/e841f3ddcf8a0e0b5e0fe8daa52acd6b

The problem is that UE4Editor is shutting off the compositor for the window manager when it gets better performance with the compositor enabled. Its a game engine with an editor built on top of it, so the wm or the internal code causes it to shut off the wm composite manager. I may just close this as its not an issue on your end.
Comment 5 Martin Flöser 2016-10-07 05:44:42 UTC
As the problem is with pure non-composited setup it's not a bug in our system. In case you have intel hardware consider switching to the modesettings xorg module. Otherwise consider creating a window specific rule to disallow this window to block compositing.
Comment 6 salamanderrake 2016-10-07 14:50:41 UTC
How do I create a window specific rule?
Comment 7 salamanderrake 2016-10-07 15:04:49 UTC
Nevermind I found the option.