This output of 'top' is grabbed from just moving the mouse around over the top of the system settings dialog. top - 12:28:24 up 2 min, 2 users, load average: 0.67, 0.28, 0.10 Tasks: 287 total, 2 running, 284 sleeping, 0 stopped, 1 zombie %Cpu(s): 9.7 us, 3.0 sy, 0.0 ni, 87.0 id, 0.0 wa, 0.2 hi, 0.2 si, 0.0 st KiB Mem : 10228404 total, 8320700 free, 1099032 used, 808672 buff/cache KiB Swap: 5181436 total, 5181436 free, 0 used. 8807936 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1861 netwiz 20 0 988516 154128 92760 R 49.2 1.5 0:16.39 systemsettings5 988 root 20 0 291872 70384 44240 S 23.3 0.7 0:15.02 Xorg 1318 netwiz 20 0 3365896 141000 87728 S 10.0 1.4 0:15.30 kwin_x11 1333 netwiz 20 0 4571460 420064 159660 S 4.3 4.1 0:12.64 plasmashell 1024 root -51 0 0 0 0 S 1.0 0.0 0:00.64 irq/40-nvidia 8 root 20 0 0 0 0 S 0.3 0.0 0:00.05 rcu_sched 492 root 20 0 0 0 0 S 0.3 0.0 0:00.05 btrfs-transacti 887 root 20 0 789412 18016 15060 S 0.3 0.2 0:00.19 NetworkManager 1885 netwiz 20 0 756992 68836 58156 S 0.3 0.7 0:00.49 konsole Disabling the desktop effects via "Alt-Shift-F12" will cause this behaviour to stop immediately. # rpm -qa | grep kwin | sort kf5-kwindowsystem-5.34.0-1.fc26.x86_64 kwin-5.9.5-2.fc26.x86_64 kwin-common-5.9.5-2.fc26.x86_64 kwin-libs-5.9.5-2.fc26.x86_64 # rpm -qa | grep nvidia | sort akmod-nvidia-381.22-2.fc26.x86_64 kmod-nvidia-4.11.3-300.fc26.x86_64-381.22-2.fc26.x86_64 nvidia-driver-381.22-6.fc26.x86_64 nvidia-driver-cuda-libs-381.22-6.fc26.x86_64 nvidia-driver-libs-381.22-6.fc26.x86_64 nvidia-libXNVCtrl-381.22-1.fc26.x86_64 nvidia-settings-381.22-1.fc26.x86_64 Am more than happy to do more debug as required.
For the record, I have managed to get systemsettings5 to show the same level of CPU usage on a laptop with an intel GPU. Another point - on the first system with the nvidia card, if I have the compositor enabled, I have observed kwin_x11 use up to 160% CPU (average of 140%) while playing a DVB-T stream within VLC. Disabling the compositor or using Alt-Shift-F12 causes the problem to disappear completely.
The following output is from an i7 laptop with only an intel GPU. I was doing nothing but moving the mouse around in circles over the 'systemsettings5' window. top - 12:12:45 up 1:24, 3 users, load average: 0.74, 0.33, 0.20 Tasks: 223 total, 1 running, 222 sleeping, 0 stopped, 0 zombie %Cpu(s): 13.8 us, 2.7 sy, 0.0 ni, 82.5 id, 0.3 wa, 0.4 hi, 0.3 si, 0.0 st KiB Mem : 8077024 total, 5125184 free, 1464352 used, 1487488 buff/cache KiB Swap: 8125436 total, 8125436 free, 0 used. 5987760 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3748 shaigh 20 0 744544 67684 56812 S 46.5 0.8 0:07.06 systemsettings5 1076 root 20 0 368044 101532 69928 S 11.6 1.3 1:23.75 Xorg 1271 shaigh 20 0 3239840 85740 61076 S 7.6 1.1 2:01.79 kwin_x11 1281 shaigh 20 0 3932612 280104 110536 S 0.7 3.5 0:51.55 plasmashell 2035 shaigh 20 0 1431656 267336 135888 S 0.7 3.3 2:41.00 chrome 125 root 20 0 0 0 0 S 0.3 0.0 0:03.57 kworker/u8:4 812 root -51 0 0 0 0 S 0.3 0.0 0:21.02 irq/30-iwlwifi 2218 shaigh 20 0 1048804 118212 68972 S 0.3 1.5 0:08.65 chrome 3298 root 20 0 0 0 0 S 0.3 0.0 0:01.18 kworker/u8:2 3709 shaigh 20 0 1002728 122836 68264 S 0.3 1.5 0:17.03 chrome 3747 shaigh 20 0 157036 4252 3680 R 0.3 0.1 0:00.11 top
I can confirm the same behavior: kwin_x11 is always at 10%, while disabling the accelleration (Ctrl+Alt-F12) it goes back to 1%/2% System: ArchLinux KDE Plasma: 5.10.1 KDE Frameworks: 5.35.0 Qt: 5.9 Kernel: 4.11.3-1-ARCH OS Type: 64 Bit Processor: i7-7500
The high cpu load of systemsettings it the root problem here. It seems to trigger repaints which explains the high cpu load in X and KWin.
I remember we already had a ticket about this, but cannot find it right now.
(And don't add back Martin, he refuses to acknowledge that compositing causes higher load. Just fix constant repaints on mouse move.)
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with Plasma 5.27 (the current LTS version)
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!
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!