Bug 481903 - stutter when framerate is lower than screen refresh
Summary: stutter when framerate is lower than screen refresh
Status: RESOLVED WORKSFORME
Alias: None
Product: kwin
Classification: Plasma
Component: compositing (show other bugs)
Version: 5.93.0
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: qt6
Depends on:
Blocks:
 
Reported: 2024-02-27 17:38 UTC by Jonathan Isom
Modified: 2024-05-14 21:07 UTC (History)
3 users (show)

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


Attachments
Video of glxgears running (1014.08 KB, video/mp4)
2024-02-27 17:38 UTC, Jonathan Isom
Details

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Description Jonathan Isom 2024-02-27 17:38:04 UTC
Created attachment 166141 [details]
Video of glxgears running

SUMMARY

I am experiencing a stutter or flicker that almost looks like it is re-showing prior frames. Experienced it in Yuzu, freetube and glxgears(when framelimited). When I tried to capture with Spectacle it didn't capture it in the recording.  Attached from my phone. 

STEPS TO REPRODUCE
1. Run  'MANGOHUD_CONFIG="fps_limit=20" mangohud glxgears'

OBSERVED RESULT
flicker

EXPECTED RESULT
No flicker


SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.93.0
KDE Frameworks Version: 5.249.0
Qt Version: 6.7.0
Kernel Version: 6.7.6-273-tkg-linux-tkg (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 4080/PCIe/SSE2
Product Name: X570M Pro4
Comment 1 Zamundaaa 2024-02-27 19:57:23 UTC
This is a NVidia driver bug, see https://gitlab.freedesktop.org/xorg/xserver/-/issues/1317 for more details
Comment 2 Jonathan Isom 2024-02-27 20:21:33 UTC
(In reply to Zamundaaa from comment #1)
> This is a NVidia driver bug, see
> https://gitlab.freedesktop.org/xorg/xserver/-/issues/1317 for more details

While I don't disagree about the Nvidia driver bug, I have been experiencing it with wayland apps as well.
Comment 3 Zamundaaa 2024-02-28 15:22:12 UTC
While NVidia has a workaround for Wayland native apps, that workaround can introduce some glitches as well. They're of a different sort though, so this is a bit surprising.
I implemented an optimization for the NVidia driver just after 5.93.0 was tagged, which might be relevant. Can you still reproduce this with 6.0.0?
Comment 4 Jonathan Isom 2024-02-28 15:38:58 UTC
(In reply to Zamundaaa from comment #3)
> While NVidia has a workaround for Wayland native apps, that workaround can
> introduce some glitches as well. They're of a different sort though, so this
> is a bit surprising.
> I implemented an optimization for the NVidia driver just after 5.93.0 was
> tagged, which might be relevant. Can you still reproduce this with 6.0.0?

I have not been able to reproduce it in any wayland apps anymore.  I am pretty sure  that  I was experiencing with a wayland app, but that one decided to stop doing it.  All the other occurrences are Xwayland.

Thank you for your time.