Bug 460276

Summary:	wayland window resize is sluggish when rendering to window using EGL
Product:	[Plasma] kwin	Reporter:	i509VCB <kde>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kde, nate, xaver.hugl
Priority:	NOR
Version First Reported In:	5.26.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Visual example of sluggish resizing

Description i509VCB 2022-10-12 06:30:47 UTC

Created attachment 152725 [details]
Visual example of sluggish resizing

SUMMARY

While working on an EGL example for Smithay's client toolkit, I noticed that resizing is not smooth.

Interestingly this sluggish resizing does not occur in Sway. This dismisses improper protocol use as the most likely cause.

Forcing use of zink (MESA_LOADER_DRIVER_OVERRIDE=zink) causes the sluggish resize to go away (likely because Zink is using Vulkan WSI under the hood).

I suspect this may involve KWin's Wayland implementation or how the client behaves because running the glutin example (available here https://github.com/rust-windowing/glutin) uses winit and has smooth resize.

STEPS TO REPRODUCE
1. Be running Plasma under Wayland
2. Run the EGL example here: https://github.com/i509VCB/client-toolkit/tree/egl-example (cargo run --example=egl --features="wayland-backend/client_system")
3. Try resizing the window
4. Window resizes sluggishly.

OBSERVED RESULT
Resizing is sluggish.

EXPECTED RESULT
Resizing should be smooth.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6

ADDITIONAL INFORMATION
Issue is reproducible on both of my machines (AMD and Intel graphics)

Multiple attachments don't seem to be allowed, here is the first 300 ish lines of WAYLAND_DEBUG that includes the protocol logs while resizing the window https://gist.github.com/i509VCB/061ec56d9bf0ae9656b41df3af35937a

Comment 1 Bug Janitor Service 2022-10-12 20:09:54 UTC

Thank you for the bug report!

Please note that Plasma 5.25.5 is not supported for much longer by KDE; supported versions are 5.24, and 5.26 or newer.

If at all possible please upgrade to a supported version and verify that the bug is still happening there.

Comment 2 i509VCB 2022-10-14 19:20:14 UTC

(In reply to Bug Janitor Service from comment #1)
> Thank you for the bug report!
> 
> Please note that Plasma 5.25.5 is not supported for much longer by KDE;
> supported versions are 5.24, and 5.26 or newer.
> 
> If at all possible please upgrade to a supported version and verify that the
> bug is still happening there.

The bug still occurs on 5.26

Comment 3 Bug Janitor Service 2022-10-20 12:27:59 UTC

A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/3077

Comment 4 Zamundaaa 2022-10-20 12:31:26 UTC

Sorry, wrong bug number. I have too many tabs open

Can you test with Weston and/or Mutter as well? Comparing them + the relevant WAYLAND_DEBUG outputs may be helpful

Comment 5 Zamundaaa 2024-05-24 14:35:38 UTC

Comment 6 Bug Janitor Service 2024-06-08 03:46:25 UTC

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Comment 7 Bug Janitor Service 2024-06-23 03:47:31 UTC

This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!