Bug 402688 - Stuttering animations on the DRM platform
Summary: Stuttering animations on the DRM platform
Status: RESOLVED NOT A BUG
Alias: None
Product: kwin
Classification: Plasma
Component: platform-drm (other bugs)
Version First Reported In: git master
Platform: Compiled Sources Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-12-29 20:59 UTC by Vlad Zahorodnii
Modified: 2019-01-11 12:15 UTC (History)
0 users

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Description Vlad Zahorodnii 2018-12-29 20:59:30 UTC 
SUMMARY
If several windows are open, then pretty much all animations stutter because `time` in prePaintScreen and prePaintWindow is bigger than vblank interval.

STEPS TO REPRODUCE
1. Start KDE Plasma on Wayland.
2. Launch several applications (e.g. Firefox, Dolphin, Konsole, etc).
   In my case, it's enough to open 5-6 apps.

OBSERVED RESULT
Choppy animations.

EXPECTED RESULT
Smooth animations.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.14.80
KDE Frameworks Version: 5.53
Qt Version: 5.12.0

ADDITIONAL INFORMATION
With 30 windows being open, animations still look smooth in the nested KWin/Wayland compositor.
Comment 1 Vlad Zahorodnii 2018-12-29 21:02:31 UTC 
It doesn't matter what standalone compositor is when running the nested compositor.
Comment 2 Vlad Zahorodnii 2019-01-11 12:15:01 UTC 
So, apparently it takes too much time to render each frame, which is kinda weird.

Marking it as invalid.