https://bugs.kde.org/show_bug.cgi?id=487780
Bug ID: 487780
Summary: Fullscreen game stutter when Plasma receives
notifications.
Classification: Plasma
Product: kwin
Version: 6.0.5
Platform: Arch Linux
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: performance
Assignee: kwin-bugs-n...@kde.org
Reporter: robert.biel...@outlook.com
Target Milestone: ---
***
If you're not sure this is actually a bug, instead post about it at
https://discuss.kde.org
If you're reporting a crash, attach a backtrace with debug symbols; see
https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***
SUMMARY
When playing fullscreen games, in particular games using Steam Proton and DXVK
(most likely all fullscreen games), there is a momentary drop in frame rate as
the desktop notification is received and again as it disappears. It is
important to clarify that nothing actually renders over the game, only the
momentary stutter that corresponds with the time the notification would appear
on the desktop had the game not been running fullscreen. This should not be
happening since nothing is actually rendered over the game and nothing should
be disturbing the rendering process with direct scanout working consistently.
This happens with all notifications and is most noticeable for me with KDE
Connect messages from my phone.
STEPS TO REPRODUCE
1. Make sure "Screen Tearing: Allow in fullscreen windows" is enabled in Plasma
display configuration.
2. Launch a Vulkan game in fullscreen mode.
3. Set VSync in the game or a constant frame rate so that the game is perfectly
smooth (Preferably use a Vulkan hood such as DXVK_HUD with frametimes graph
overlay).
4. Trigger a desktop notification such as a text message with KDE Connect via
Android.
5. Observe a sudden momentary stutter and corresponding spike in the frametime
graph when a notification comes in to the desktop such as KDE Connect and once
again when it disappears.
OBSERVED RESULT
A momentary stutter and spike in frametime is observed when Plasma gets a
notification in an otherwise perfectly smooth VSync'd game experience.
EXPECTED RESULT
The frame rate should remain perfectly smooth with no stutter during background
notification reception and frametimes should be consistent all the time.
SOFTWARE/OS VERSIONS
Operating System: EndeavourOS
KDE Plasma Version: 6.0.5
KDE Frameworks Version: 6.2.0
Qt Version: 6.7.1
Kernel Version: 6.9.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 32 × AMD Ryzen 9 5950X 16-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: AMD Radeon RX 5700 XT
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: X570 AORUS XTREME
System Version: -CF
ADDITIONAL INFORMATION
Mesa 24.1.0 with RADV drivers.
--
You are receiving this mail because:
You are watching all bug changes.
