kscreen.xcb.helper flooding syslog

[hstoellinger]

Hello,
I am on Kubuntu 20.10 (see enclosed inxi-Output). In general, things are working fine. However, sometimes my system seems to perform worse than what I experienced under 20.04. Looking at syslog, i notice loads of the following messages, involving kscreen.xcb.helper:

kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
kscreen.xcb.helper: #011Output: 586
kscreen.xcb.helper: #011Property: Backlight
kscreen.xcb.helper: #011State (newValue, Deleted: 0

):

I wonder what's the reason.

Here comes the inxi -F output:

System: Host: hslaptop Kernel: 5.8.0-26-generic x86_64 bits: 64 Console: tty 8 Distro: Ubuntu 20.10 (Groovy Gorilla)
Machine: Type: Laptop System: Sony product: VGN-AW11M_H v: C6010CXT serial: 28282369-5004308
Mobo: Sony model: VAIO serial: N/A BIOS: American Megatrends v: R0200Y2 date: 08/12/2008
Battery: ID-1: BAT0 charge: 72.2 Wh condition: 72.2/73.3 Wh (98%)
CPU: Info: Dual Core model: Intel Core2 Duo P8400 bits: 64 type: MCP L2 cache: 3072 KiB
Speed: 1596 MHz min/max: 1600/2267 MHz Core speeds (MHz): 1: 1596 2: 1596
Graphics: Device-1: NVIDIA G98M [GeForce 9300M GS] driver: nvidia v: 340.108
Device-2: Ricoh Visual Communication Camera VGP-VCC9 [R5U870] type: USB driver: uvcvideo
Display: server: X.org 1.20.9 driver: nvidia note: display driver n/a FAILED: nvidia unloaded: modesetting
tty: 127x28
Message: Advanced graphics data unavailable in console for root.
Audio: Device-1: Intel 82801I HD Audio driver: snd_hda_intel
Sound Server: ALSA v: k5.8.0-26-generic
Network: Device-1: Marvell 88E8055 PCI-E Gigabit Ethernet driver: sky2
IF: enp2s0 state: up speed: 1000 Mbps duplex: full mac: 00:1d:ba:86:ca:c7
Device-2: Intel WiFi Link 5100 driver: iwlwifi
IF: wlp5s0 state: down mac: 00:21:5d:b5:9a:72
Drives: Local Storage: total: 298.09 GiB used: 188.46 GiB (63.2%)
ID-1: /dev/sda vendor: Fujitsu model: MHZ2320BH G1 size: 298.09 GiB
Partition: ID-1: / size: 94.09 GiB used: 71.34 GiB (75.8%) fs: ext4 dev: /dev/sda5
Swap: ID-1: swap-1 type: partition size: 8.41 GiB used: 456.1 MiB (5.3%) dev: /dev/sda3
ID-2: swap-2 type: partition size: 9.97 GiB used: 0 KiB (0.0%) dev: /dev/sda1
Sensors: System Temperatures: cpu: 59.0 C mobo: 59.0 C
Fan Speeds (RPM): N/A
Info: Processes: 276 Uptime: 4h 18m Memory: 3.81 GiB used: 2.46 GiB (64.6%) Init: systemd runlevel: 5 Shell: Sudo
inxi: 3.1.07System: Host: hslaptop Kernel: 5.8.0-26-generic x86_64 bits: 64 Console: tty 8 Distro: Ubuntu 20.10 (Groovy Gorilla)
Machine: Type: Laptop System: Sony product: VGN-AW11M_H v: C6010CXT serial: 28282369-5004308
Mobo: Sony model: VAIO serial: N/A BIOS: American Megatrends v: R0200Y2 date: 08/12/2008
Battery: ID-1: BAT0 charge: 72.2 Wh condition: 72.2/73.3 Wh (98%)
CPU: Info: Dual Core model: Intel Core2 Duo P8400 bits: 64 type: MCP L2 cache: 3072 KiB
Speed: 1596 MHz min/max: 1600/2267 MHz Core speeds (MHz): 1: 1596 2: 1596
Graphics: Device-1: NVIDIA G98M [GeForce 9300M GS] driver: nvidia v: 340.108
Device-2: Ricoh Visual Communication Camera VGP-VCC9 [R5U870] type: USB driver: uvcvideo
Display: server: X.org 1.20.9 driver: nvidia note: display driver n/a FAILED: nvidia unloaded: modesetting
tty: 127x28
Message: Advanced graphics data unavailable in console for root.
Audio: Device-1: Intel 82801I HD Audio driver: snd_hda_intel
Sound Server: ALSA v: k5.8.0-26-generic
Network: Device-1: Marvell 88E8055 PCI-E Gigabit Ethernet driver: sky2
IF: enp2s0 state: up speed: 1000 Mbps duplex: full mac: 00:1d:ba:86:ca:c7
Device-2: Intel WiFi Link 5100 driver: iwlwifi
IF: wlp5s0 state: down mac: 00:21:5d:b5:9a:72
Drives: Local Storage: total: 298.09 GiB used: 188.46 GiB (63.2%)
ID-1: /dev/sda vendor: Fujitsu model: MHZ2320BH G1 size: 298.09 GiB
Partition: ID-1: / size: 94.09 GiB used: 71.34 GiB (75.8%) fs: ext4 dev: /dev/sda5
Swap: ID-1: swap-1 type: partition size: 8.41 GiB used: 456.1 MiB (5.3%) dev: /dev/sda3
ID-2: swap-2 type: partition size: 9.97 GiB used: 0 KiB (0.0%) dev: /dev/sda1
Sensors: System Temperatures: cpu: 59.0 C mobo: 59.0 C
Fan Speeds (RPM): N/A
Info: Processes: 276 Uptime: 4h 18m Memory: 3.81 GiB used: 2.46 GiB (64.6%) Init: systemd runlevel: 5 Shell: Sudo
inxi: 3.1.07

Any idea what's wrong?
Regards
H. Stoellinger

[GreyGeek]

Found this possible solution on the web:

It's a re-occurring bug: https://bugs.launchpad.net/kubuntu-ppa/+bug/1579735

I have found at least two solutions: 

1) Just added the following line into
/etc/profile.d/kf5.sh
export QT_LOGGING_RULES="kscreen.xcb.helper=false"
Probably, it could be worth mention in the book.

You may have to create kf5.sh

OR,
2)
"After getting really annoyed at this bug, and it not being fixed I've found a workaround.
Pipe all KScreen stdout and stderr to null.
Edit /usr/share/dbus-1/services/org.kde.kscreen.service
To say
[D-BUS Service]
Name=org.kde.KScreen
Exec=/bin/sh -c '/usr/lib/x86_64-linux-gnu/libexec/kf5/kscreen_backend_launcher > /dev/null 2>/dev/null' "

The last fix is from 2-24-2017. The last entry is for Kubuntu 20.10 on 12-28-2020.

[hstoellinger]

xcb.helper messages flooding syslog

Thanks! I tried both your suggestions and they both work.
Regards from Austria
H. Stoellinger