High CPU usage from kwin_wayland after Plasma 6.7 upgrade

gi1242 · 2026-06-20 16:59:13

Hi all,

After upgrading to Plasma 6.7 I'm finding the kwin_wayland takes some 8%CPU when idle with nothing open. When I have firefox open on some sites it spikes up to 50% even though there are no animations (except a blinking cursor, like the arch forums). I tried setting my environment variables to force wayland (MOZ_ENABLE_WAYLAND=1, QT_QPA_PLATFORM=wayland), and I played around with my i915 module parameters (enable_psr=0, enable_fbc=0). But no luck. Any idea what the problem might be and how I can fix it?

If it helps, here's my sytem info:

Operating System: Arch Linux
KDE Plasma Version: 6.7.0
KDE Frameworks Version: 6.27.0
Qt Version: 6.11.1
Kernel Version: 6.18.36-1-lts (64-bit)
Graphics Platform: Wayland
Processors: 6 × Intel® Core™ i5-9600K CPU @ 3.70GHz
Memory: 16 GiB of RAM (15.3 GiB usable)
Graphics Processor: Mesa Intel® UHD Graphics 630

Thanks in advance,

GI

seth · 2026-06-20 19:10:59

qdbus6 org.kde.KWin /KWin supportInformation
glxinfo -B

Does intel_gpu_top suggest the IGP is being utilized?

gi1242 · 2026-06-21 22:15:58

Actually I think there's a bug with the new code. I restarted after setting

KWIN_DRM_USE_MODIFIERS=0
KWIN_DRM_NO_ATOMIC=1

in `~/.config/environment.d/90-wayland.conf`, and the CPU usage dropped dramatically.

gi1242 · 2026-06-21 22:22:40

Thanks for your response.

seth wrote:

qdbus6 org.kde.KWin /KWin supportInformation
glxinfo -B
Does intel_gpu_top suggest the IGP is being utilized?

Now that I disabled atomic (whatever that means), it looks like plasmashell takes some of the GPU (3%ish when I'm normally typing).

Here's the supportInformation:

Version
=======
KWin version: 6.7.0
Qt Version: 6.11.1
Qt compile version: 6.11.1
XCB compile version: 1.17.0

Operation Mode: Wayland

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_X11_XCB: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 12401012
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
RES: yes; Version: 0x12

Decoration
==========
Plugin: org.kde.breeze
Theme: 
Plugin recommends border size: None
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
alwaysShowExcludeFromCapture: false
decorationButtonsLeft: 0, 2, 12
decorationButtonsRight: 6, 3, 4, 5
borderSize: 0
gridUnit: 12
font: Noto Sans,12,-1,5,400,0,0,0,0,0,0,0,0,0,0,1,SemiCondensed,0,0
smallSpacing: 3
largeSpacing: 12

LogicalOutput backend
==============
Name: DRM
Atomic Mode Setting on GPU 0: true

Cursor
======
themeName: breeze_cursors
themeSize: 24

Options
=======
focusPolicy: ClickToFocus
xwaylandCrashPolicy: 1
xwaylandMaxCrashCount: 3
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
separateScreenFocus: true
placement: 5
activationDesktopPolicy: SwitchToOtherDesktop
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
edgeBarrier: 100
cornerBarrier: 1
rollOverDesktops: true
perOutputVirtualDesktops: false
focusStealingPreventionLevel: 0
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5013
operationMaxButtonRightClick: 5012
commandActiveTitlebar1: MouseRaise
commandActiveTitlebar2: MouseNothing
commandActiveTitlebar3: MouseOperationsMenu
commandInactiveTitlebar1: MouseActivateAndRaise
commandInactiveTitlebar2: MouseNothing
commandInactiveTitlebar3: MouseOperationsMenu
commandWindow1: MouseActivateRaiseOnReleaseAndPassClick
commandWindow2: MouseActivateAndPassClick
commandWindow3: MouseActivateAndPassClick
commandWindowWheel: MouseNothing
commandAll1: MouseUnrestrictedMove
commandAll2: MouseToggleRaiseAndLower
commandAll3: MouseUnrestrictedResize
keyCmdAllModKey: 16777250
doubleClickBorderToMaximize: true
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderAllScreenCorner: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
compositingMode: 1
allowTearing: true
interactiveWindowMoveEnabled: true
pictureInPictureHomeCorner: BottomRightCorner
pictureInPictureMargin: 20
overlayVirtualKeyboardOnWindows: false

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Number of Screens: 1

Screen 0:
---------
Name: DP-1
Enabled: 1
Geometry: 0,0,3840x2160
Physical size: 600x340mm
Scale: 1
Refresh Rate: 59997
Adaptive Sync: incapable

Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) UHD Graphics 630 (CFL GT2)
OpenGL version string: 4.6 (Core Profile) Mesa 26.1.3-arch1.2
OpenGL platform interface: EGL
OpenGL shading language version string: 4.60
Driver: Intel
GPU class: Coffee Lake
OpenGL version: 4.6
GLSL version: 4.60
Mesa version: 26.1.3
X server version: 1.24.1
Linux kernel version: 6.18.36
Direct rendering: Requires strict binding: no
Virtual Machine:  no
OpenGL 2 Shaders are used

Loaded Effects:
---------------
shakecursor
outputlocator
colorpicker
zoom
screenedge
blur
logout
sessionquit
login
slidingpopups
slidingnotifications
translucency
windowaperture
squash
dimscreen
fullscreen
maximize
frozenapp
fadingpopups
scale
dialogparent
windowview
tileseditor
overview
highlightwindow
blendchanges
startupfeedback
systembell
screentransform
kscreen
invert

Currently Active Effects:
-------------------------
blur

Effect Settings:
----------------
shakecursor:

outputlocator:

colorpicker:

zoom:
zoomFactor: 1.2
mouseTracking: 0
focusDelay: 350
moveFactor: 20
targetZoom: 1

screenedge:

blur:

logout:
pluginId: logout
isActiveFullScreenEffect: false

sessionquit:
pluginId: sessionquit
isActiveFullScreenEffect: false

login:
pluginId: login
isActiveFullScreenEffect: false

slidingpopups:
slideInDuration: 1
slideOutDuration: 1

slidingnotifications:

translucency:
pluginId: translucency
isActiveFullScreenEffect: false

windowaperture:
pluginId: windowaperture
isActiveFullScreenEffect: false

squash:
pluginId: squash
isActiveFullScreenEffect: false

dimscreen:
pluginId: dimscreen
isActiveFullScreenEffect: false

fullscreen:
pluginId: fullscreen
isActiveFullScreenEffect: false

maximize:
pluginId: maximize
isActiveFullScreenEffect: false

frozenapp:
pluginId: frozenapp
isActiveFullScreenEffect: false

fadingpopups:
pluginId: fadingpopups
isActiveFullScreenEffect: false

scale:
pluginId: scale
isActiveFullScreenEffect: false

dialogparent:
pluginId: dialogparent
isActiveFullScreenEffect: false

windowview:
activeView: 
delegate: 
animationDuration: 1
ignoreMinimized: false
mode: 
partialActivationFactor: 0
gestureInProgress: false
searchText: 
selectedIds: 

tileseditor:
activeView: 
delegate: 
animationDuration: 200

overview:
activeView: 
delegate: 
animationDuration: 1
ignoreMinimized: false
filterWindows: true
organizedGrid: true
overviewPartialActivationFactor: 0
overviewGestureInProgress: false
transitionPartialActivationFactor: 0
transitionGestureInProgress: false
gridPartialActivationFactor: 0
gridGestureInProgress: false
searchText: 

highlightwindow:

blendchanges:

startupfeedback:
type: 1

systembell:

screentransform:

kscreen:

invert:


Loaded Plugins:
---------------
BounceKeysPlugin
KeyNotificationPlugin
MouseKeysPlugin
SlowKeysPlugin
StickyKeysPlugin
TouchpadShortcutsPlugin
buttonsrebind
eis
gamecontroller
krunnerintegration
nightlight
screencast
screenshot

Available Plugins:
------------------
BounceKeysPlugin
KeyNotificationPlugin
MouseKeysPlugin
SlowKeysPlugin
StickyKeysPlugin
TouchpadShortcutsPlugin
buttonsrebind
eis
gamecontroller
krunnerintegration
nightlight
screencast
screenshot

name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) UHD Graphics 630 (CFL GT2) (0x3e98)
    Version: 26.1.3
    Accelerated: yes
    Video memory: 15644MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) UHD Graphics 630 (CFL GT2)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 26.1.3-arch1.2
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 4.6 (Compatibility Profile) Mesa 26.1.3-arch1.2
OpenGL shading language version string: 4.60
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile

OpenGL ES profile version string: OpenGL ES 3.2 Mesa 26.1.3-arch1.2
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

Arch Linux

#1 2026-06-20 16:59:13

High CPU usage from kwin_wayland after Plasma 6.7 upgrade

#2 2026-06-20 19:10:59

Re: High CPU usage from kwin_wayland after Plasma 6.7 upgrade

#3 2026-06-21 22:15:58

Re: High CPU usage from kwin_wayland after Plasma 6.7 upgrade

#4 2026-06-21 22:22:40

Re: High CPU usage from kwin_wayland after Plasma 6.7 upgrade

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