Kwin Overloads CPU After Updates [Solved]

[tonyawards]

Fitzcarraldo, I just saw your post after putting my last one up - was busy turning off Desktop Effects via the terminal and rebooting a few times.
That did not give any improvement, unfortunately. And, moving a bit too fast, I renamed the .kde4backup back to .kde4 (mv rather than cp) and forgot to make it recursive. Now with my original .kde4 it won't get past the first icon in the KDE login sequence.

So I had to rename it again (to 'bad'), and reboot like before to allow a fresh, default one to be auto-generated. Is there any way to merge the old settings with the newly created .kde4 so I don't have to reconfigure everything? Krusader or something? Comes from rushing past myself too much... all my fault.

Anyway - I did see your post, and you may well be right. It does seem that the nvidia-drivers upgraded right during one of those days, in a moderately large batch of updates.

I'll keep researching this and working on the issue tonight (US-PDT), and try again to get into a normal session now that Desktop Effects is off. I suppose I can wait it out in Failsafe if I have to, as well.

As to all the D-Bus errors, I suppose that shoud be another thread (after I do some more looking online); which forum is best if I need to post again on that issue?

[Fitzcarraldo]

One of those D-Bus error messages is a known bug in KDE, and it even happens on my main laptop running KDE (notice the same message in the second line of the Konsole output I've posted below) but does not seem to have any adverse effects on my experience using KDE 4.8.2:

Code: Select all

$ ./screenfetch-dev -D 'Gentoo'
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
         -/oyddmdhs+:.
     -odNMMMMMMMMNNmhy+-`             fitzcarraldo@meshedgedx
   -yNMMMMMMMMMMMNNNmmdhy+-           OS: Gentoo x86_64
 `omMMMMMMMMMMMMNmdmmmmddhhy/`        Kernel: 3.2.1-gentoo-r2
 omMMMMMMMMMMMNhhyyyohmdddhhhdo`      Uptime: 20h 10m
.ydMMMMMMMMMMdhs++so/smdddhhhhdm+`    Packages: 2251
 oyhdmNMMMMMMMNdyooydmddddhhhhyhNd.   Shell: bash
  :oyhhdNNMMMMMMMNNNmmdddhhhhhyymMh   Resolution: 1440x900
    .:+sydNMMMMMNNNmmmdddhhhhhhmMmy   DE: KDE
       /mMMMMMMNNNmmmdddhhhhhmMNhs:   WM: KWin
    `oNMMMMMMMNNNmmmddddhhdmMNhs+`    WM Theme: Air
  `sNMMMMMMMMNNNmmmdddddmNMmhs/.      GTK2 Theme: oxygen
 /NMMMMMMMMNNNNmmmdddmNMNdso:`        GTK3 Theme: Not Found
+MMMMMMMNNNNNmmmmdmNMNdso/-           Icon Theme: oxygen
MNNNNNNNmmmmmNNMmhs+/-`               Font: DejaVu Sans,8,-1,5,50,0,0,0,0,0
/hMMNNNNNNNNMNdhs++/-`                CPU: Intel(R) Core(TM) i7 CPU Q 720 @ 1.60GHz
`/ohdmmddhys+++/:.`                   RAM: 1719MB / 3944MB
  `-//////:--.
$

See also the following KDE Review Board post: Summary: Avoid QDBusConnection Qt warning message for each KUniqueApplication.

Something else you could try if you don't want to downgrade the NVIDIA video driver (although I doubt the following will make any difference, as the fundamental problem seems to be latest version of the video driver):

Create the file /etc/X11/xorg.conf.d/90-extensions.conf containing the following:

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Section "Extensions"
   Option "Composite" "Disable"
EndSection

If it makes no difference after you reboot, you can just delete the file. If the directory /etc/X11/xorg.conf.d/ does not already exist, just create it. You can leave it there afterwards even if it is empty, as it's always useful to have if you need to add any tweaks to your X Windows configuration in future.

[tonyawards]

Fitzcarraldo, well, believe it or not, your last suggestion to create the 90-extensions.conf file appears to have gotten things back on track. I did already have /etc/X11/xorg.conf.d/ so I just placed the file in there, rebooted, and I'm in a normal Plasma session and (for now...) running smoothly at a normal speed. Kwin is showing a negligible CPU load like it should as well.

And I was just getting ready to downgrade the nvidia driver, too. Spent most of last night Googling for some relevant solution, but with little success.

What did that actually do – did it somehow reinforce or override the

Hmm... I'll bet that Desktop Effects are disabled in the KDE Failsafe Mode. I wonder if you have Desktop Effects enabled under your normal KDE login? If you do, try turning them off. To do that, edit the file ~/.kde4/share/config/kwinrc and change "Enabled=true" to "Enabled=false" in the [Compositing] section.

disabling that I did before?

But – to be thorough, while I was writing this I just tested turning on the Desktop Effects setting with alt+shift+F12, and that brought things to a halt again as before. although last night without the 90-extensions.conf file in place, just disabling them did not seem to solve the issue. So I can't be 100% sure, but it does seem that the workaround takes both actions to have an effect. We'll see, I guess.

I'm going to leave it like this for the time being, and wait to receive the (hopefully) patched nvidia driver set when they fix it. I'll keep this open for now and report back with a [Solved] when they update the driver. But this certainly works for the time being.

Thank you once again for all your help.

As to those D-Bus errors (I believe I have rather more than you do), and krunner not working etc. as a result, that's a thread for another day, I suppose.

[tonyawards]

Well, I tried re-enabling Desktop Effects after the latest round of updates today, which included the nvidia set going to 295.49. I changed "Enabled" back to =true, rebooted, and everything is running with all kde effects in place as fast as before.

I did leave the 90-extensions.conf file in place (what can it hurt?), but it does seem that all is fine with the latest nvidia driver and userspace combo. So I feel safe in marking this one as [Solved].