Bug 488848 - Mouse pointer becomes laggy on logout screen due to blur effect
Summary: Mouse pointer becomes laggy on logout screen due to blur effect
Status: VERIFIED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: effects-various (show other bugs)
Version: 6.1.0
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
: 489456 (view as bug list)
Depends on:
Blocks:
 
Reported: 2024-06-20 23:25 UTC by medin
Modified: 2024-10-24 13:38 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed In: 6.2.0
Sentry Crash Report:


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Description medin 2024-06-20 23:25:31 UTC
If you click on Logout, Shutdown or Restart, the confirmation layer appears, then you start moving the mouse pointer inside that layer, the pointer becomes laggy and slow like it's dragged by something, and at random time the pointer arrow becomes bigger.

Operating System: Manjaro Linux 
KDE Plasma Version: 6.1.0
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.1
Kernel Version: 6.9.5-1-MANJARO (64-bit)
Graphics Platform: Wayland
Comment 1 medin 2024-06-20 23:59:12 UTC
It seems the pointer becoming big is due to that shake cursor effect, but the slowness is always present in that confirmation layer, the previous one didn't have this problem.
Comment 2 Nate Graham 2024-06-21 20:33:06 UTC
Maybe the shader that drives this became slower somehow? I cannot reproduce the issue on my system which uses 225% scale on a 4k screen, which is generally graphically slow enough to trigger issues like the one you're reporting.

Can you paste the output of `env`?
Comment 3 medin 2024-06-21 20:42:44 UTC
(In reply to Nate Graham from comment #2)
> Can you paste the output of `env`?


This is the result from the laptop with lowest specs (100% scale), where the slowness is more visible:

CALIBRE_USE_SYSTEM_THEME=1
CASROOT=/usr
COLORFGBG=15;0
COLORTERM=truecolor
CSF_DrawPluginDefaults=/usr/share/opencascade/resources/DrawResources
CSF_EXCEPTION_PROMPT=1
CSF_IGESDefaults=/usr/share/opencascade/resources/XSTEPResource
CSF_LANGUAGE=us
CSF_MDTVTexturesDirectory=/usr/share/opencascade/resources/Textures
CSF_MIGRATION_TYPES=/usr/share/opencascade/resources/StdResource/MigrationSheet.txt
CSF_OCCTResourcePath=/usr/share/opencascade/resources
CSF_PluginDefaults=/usr/share/opencascade/resources/StdResource
CSF_SHMessage=/usr/share/opencascade/resources/SHMessage
CSF_STEPDefaults=/usr/share/opencascade/resources/XSTEPResource
CSF_ShadersDirectory=/usr/share/opencascade/resources/Shaders
CSF_StandardDefaults=/usr/share/opencascade/resources/StdResource
CSF_StandardLiteDefaults=/usr/share/opencascade/resources/StdResource
CSF_TObjDefaults=/usr/share/opencascade/resources/StdResource
CSF_TObjMessage=/usr/share/opencascade/resources/TObj
CSF_XCAFDefaults=/usr/share/opencascade/resources/StdResource
CSF_XSMessage=/usr/share/opencascade/resources/XSMessage
CSF_XmlOcafResource=/usr/share/opencascade/resources/XmlOcafResource
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1007/bus
DEBUGINFOD_CACHE_PATH=/var/tmp/.debuginfod_client/
DEBUGINFOD_URLS=https://debuginfod.archlinux.org 
DESKTOP_SESSION=plasmawayland
DISPLAY=:1
DOTNET_CLI_TELEMETRY_OPTOUT=1
DRAWDEFAULT=/usr/share/opencascade/resources/DrawResources/DrawDefault
DRAWHOME=/usr/share/opencascade/resources/DrawResources
FREETYPE_PROPERTIES=truetype:interpreter-version=40
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/mohamed/.gtkrc-2.0:/home/mohamed/.config/gtkrc-2.0
GTK_RC_FILES=/etc/gtk/gtkrc:/home/mohamed/.gtkrc:/home/mohamed/.config/gtkrc
HG=/usr/bin/hg
HOME=/home/mohamed
ICEAUTHORITY=/run/user/1007/iceauth_cnRINN
INVOCATION_ID=2339e9b7502e4d6e8d2f4fee28594d67
JOURNAL_STREAM=9:9680
KDE_APPLICATIONS_AS_SCOPE=1
KDE_FULL_SESSION=true
KDE_SESSION_UID=1007
KDE_SESSION_VERSION=6
KONSOLE_DBUS_SERVICE=:1.74
KONSOLE_DBUS_SESSION=/Sessions/2
KONSOLE_DBUS_WINDOW=/Windows/1
KONSOLE_VERSION=240501
LANG=en_US.UTF-8
LANGUAGE=
LC_ADDRESS=en_US.UTF-8
LC_IDENTIFICATION=en_US.UTF-8
LC_MEASUREMENT=en_US.UTF-8
LC_MONETARY=en_US.UTF-8
LC_NAME=en_US.UTF-8
LC_NUMERIC=en_US.UTF-8
LC_PAPER=en_US.UTF-8
LC_TELEPHONE=en_US.UTF-8
LC_TIME=en_US.UTF-8
LOGNAME=mohamed
MAIL=/var/spool/mail/mohamed
MANAGERPID=1252
MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/user.slice/user-1007.slice/user@1007.service/session.slice/plasma-plasmashell.service/memory.pressure
MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
MMGT_CLEAR=1
MOTD_SHOWN=pam
PAM_KWALLET5_LOGIN=/run/user/1007/kwallet5.socket
PATH=/home/mohamed/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
PROFILEHOME=
PWD=/home/mohamed
QT_AUTO_SCREEN_SCALE_FACTOR=0
QT_LINUX_ACCESSIBILITY_ALWAYS_ON=1
QT_WAYLAND_RECONNECT=1
SESSION_MANAGER=local/manjaro-med:@/tmp/.ICE-unix/1446,unix/manjaro-med:/tmp/.ICE-unix/1446
SHELL=/usr/bin/bash
SHELL_SESSION_ID=e4e431336fdc476195e744e51e2661a4
SYSTEMD_EXEC_PID=1469
TERM=xterm-256color
USER=mohamed
WAYLAND_DISPLAY=wayland-0
WINDOWID=3
XAUTHORITY=/run/user/1007/xauth_yMIQVC
XDG_ACTIVATION_TOKEN=kwin-7
XDG_CONFIG_DIRS=/home/mohamed/.config/kdedefaults:/etc/xdg:/usr/share/manjaro-kde-settings/xdg
XDG_CURRENT_DESKTOP=KDE
XDG_MENU_PREFIX=plasma-
XDG_RUNTIME_DIR=/run/user/1007
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=KDE
XDG_SESSION_ID=2
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session1
XDG_SESSION_TYPE=wayland
XDG_VTNR=1
XKB_DEFAULT_LAYOUT=fr
XKB_DEFAULT_MODEL=pc105
_JAVA_OPTIONS=-Dawt.useSystemAAFontSettings=on -Dswing.aatext=true -Dswing.defaultlaf=javax.swing.plaf.nimbus.NimbusLookAndFeel -Dswing.crossplatformlaf=javax.swing.plaf.nimbus.NimbusLookAndFeel 
SHLVL=1
OLDPWD=/home/mohamed
LESS_TERMCAP_mb=
LESS_TERMCAP_md=
LESS_TERMCAP_me=
LESS_TERMCAP_se=
LESS_TERMCAP_so=
LESS_TERMCAP_ue=
LESS_TERMCAP_us=
LESS=-R
LS_OPTIONS=--color=auto
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.7z=01;31:*.ace=01;31:*.alz=01;31:*.apk=01;31:*.arc=01;31:*.arj=01;31:*.bz=01;31:*.bz2=01;31:*.cab=01;31:*.cpio=01;31:*.crate=01;31:*.deb=01;31:*.drpm=01;31:*.dwm=01;31:*.dz=01;31:*.ear=01;31:*.egg=01;31:*.esd=01;31:*.gz=01;31:*.jar=01;31:*.lha=01;31:*.lrz=01;31:*.lz=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.lzo=01;31:*.pyz=01;31:*.rar=01;31:*.rpm=01;31:*.rz=01;31:*.sar=01;31:*.swm=01;31:*.t7z=01;31:*.tar=01;31:*.taz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tgz=01;31:*.tlz=01;31:*.txz=01;31:*.tz=01;31:*.tzo=01;31:*.tzst=01;31:*.udeb=01;31:*.war=01;31:*.whl=01;31:*.wim=01;31:*.xz=01;31:*.z=01;31:*.zip=01;31:*.zoo=01;31:*.zst=01;31:*.avif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*~=00;90:*#=00;90:*.bak=00;90:*.crdownload=00;90:*.dpkg-dist=00;90:*.dpkg-new=00;90:*.dpkg-old=00;90:*.dpkg-tmp=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:*.swp=00;90:*.tmp=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:
P9K_SSH=0
_P9K_SSH_TTY=/dev/pts/3
P9K_TTY=old
_P9K_TTY=/dev/pts/3
_=/usr/bin/env
Comment 4 medin 2024-06-22 15:29:22 UTC
After trying many things, it seems the culprit is that blur effect, disabling it seems to fix the slowness and the mouse cursor regains its smoothness, but I get a transparent confirmation layer which is not looking good.

Is there any way to apply a simple solid color to that layer instead of blurring the whole screen?
Comment 5 Nate Graham 2024-06-26 19:52:13 UTC
Thanks. Indeed it is the blur effect. I've also thought that it was unnecessary here since you can barely see the blurred content anyway. 

FWIW I've found a way to reproduce this myself: plug in a second monitor. Then I get the same lag.

Regardless, moving to KWin for now to debug why the blur here is slow.
Comment 6 Nate Graham 2024-07-02 19:57:16 UTC
*** Bug 489456 has been marked as a duplicate of this bug. ***
Comment 7 Zamundaaa 2024-07-17 15:09:59 UTC
hmm, the cursor should be independent from compositing performance, and on my PC it still is.
Could you check if this also happens with KWIN_DRM_DISABLE_TRIPLE_BUFFERING=1 set? I suspect this might be the same as bug 488843
Comment 8 medin 2024-07-17 19:05:00 UTC
(In reply to Zamundaaa from comment #7)
> hmm, the cursor should be independent from compositing performance, and on
> my PC it still is.
> Could you check if this also happens with
> KWIN_DRM_DISABLE_TRIPLE_BUFFERING=1 set? I suspect this might be the same as
> bug 488843

Even if I set KWIN_DRM_DISABLE_TRIPLE_BUFFERING=1 in "/etc/environment" then reboot, the lagging is still happening.

If disable Blur effect, the mouse's movements immediately become fast.
Comment 9 Nate Graham 2024-07-24 18:30:50 UTC
I'm somewhat at a loss to explain how, but https://invent.kde.org/plasma/kwin/-/commit/b0a5918db9e281e8b680317eb35a7d20084e10c6 has fixed this for me.
Comment 10 medin 2024-10-24 10:55:15 UTC
(In reply to Nate Graham from comment #9)
> I'm somewhat at a loss to explain how, but
> https://invent.kde.org/plasma/kwin/-/commit/
> b0a5918db9e281e8b680317eb35a7d20084e10c6 has fixed this for me.

I confirm on Plasma 6.2.2, the lagging is gone with Blur enabled.