KDE high dom0 CPU usage

[54th Parallel]

Quick question:

I decided to try out KDE on 4.0 and was liking it until I noticed the low overall framerate and the high CPU usage of dom0 shown in xentop whenever there's motion (like dragging windows around). Since I'm using an i7-1065G7, power shouldn't be an issue, so I was surprised. 

Is there any way I can fix this? Has anyone here experienced this?

[Chris Laprise]

Not an issue with dom0 KDE here. But I did have this problem with
k/ubuntu on my new AMD Ryzen Thinkpad... graphics driver was not working
and defaulted to a non-accelerated framebuffer mode. In this case I had
to upgrade the kernel to resolve it.

Check output of 'sudo lspci -nnk' and look for the section with 'VGA'.
If it says 'unclaimed' then your graphics driver isn't working. The
'lshw' command can also be used for a different view; it will show the
VGA section with a line 'configuration: driver=<yourGPUkerneldriver>' if
its working or the 'driver' part will be absent if its not working.

--
Chris Laprise, tas...@posteo.net
https://github.com/tasket
https://twitter.com/ttaskett
PGP: BEE2 20C5 356E 764A 73EB 4AB3 1DC4 D106 F07F 1886

[54th Parallel]

On Thursday, 20 August 2020 at 06:58:35 UTC+8 Chris Laprise wrote:

Not an issue with dom0 KDE here. But I did have this problem with
k/ubuntu on my new AMD Ryzen Thinkpad... graphics driver was not working
and defaulted to a non-accelerated framebuffer mode. In this case I had
to upgrade the kernel to resolve it.

Check output of 'sudo lspci -nnk' and look for the section with 'VGA'.
If it says 'unclaimed' then your graphics driver isn't working. The
'lshw' command can also be used for a different view; it will show the
VGA section with a line 'configuration: driver=<yourGPUkerneldriver>' if
its working or the 'driver' part will be absent if its not working.

--
Chris Laprise, tas...@posteo.net
https://github.com/tasket
https://twitter.com/ttaskett
PGP: BEE2 20C5 356E 764A 73EB 4AB3 1DC4 D106 F07F 1886

lspci -nnk showed VGA working fine, but the output gave me other ideas (lshw not available on dom0). I modified xen.cfg so that i915.alpha_support=1 became i915.preliminary_hw_support=1 but that made things worse. I then switched to a newer kernel (5.6)  and saw a minor framerate improvement, but the high CPU usage remained. I removed iommu=no-igfx and saw a better framerate, but again, high CPU usage remained. 

I looked around and found that KDE and NVidia don't mix--at least for the older versions of KDE (https://www.phoronix.com/scan.php?page=news_item&px=NVIDIA-KDE-High-CPU-Fix). The KDE Plasma version of dom0 current is 5.10, but the NVidia GPU in my laptop (which is weaker than my iGPU's) needs 5.16. But the thing is--I don't remember installing an NVidia propietary driver at all. Anyways, I installed the recommended fix ('export __GL_MaxFramesAllowed=1' in an executable script in /etc/profile.d) but that didn't work as well, so I gave up and uninstalled KDE. 

[Chris Laprise]

I switch off any nvidia gpus before installation. The company is
anti-open source and I'm not interested in running drivers that are the
result of a cat-and-mouse obfuscation game.

[54th Parallel]

I tried to find ways to disable my Nvidia GPU before my first installation since the i7-1065G7 has a more powerful integrated one but didn't find anything. The BIOS doesn't have anything either. I didn't install any drivers but my display works fine, so am I free of Nvidia drivers?

Oh, and quick question about Qubes VM hardening: I have it installed and working fine on all of my VMs except one, where every time that VM boots up, it automatically starts an xterm window headlined with '** VM-BOOT-PROTECT SERVICE SHELL' . This happens on a debian-10-minimal sys-dispVM when VM-boot-protect (not root) is enabled and disabled. DispVM Template displays the same behavior with an added error line 'cat: /var/run/vm-boot-protect-error: No such file or directory'.  The DVM template has VM-boot-protect-root enabled.

Problem persists after reinstallation of hardening in template. It doesn't seem like a major error, but it's bugging me. I'd be grateful for any pointers

[donoban]

Maybe your problem is Opengl not being hardware accelerated. Try
switching to XRender under System Settings -> Display and Monitor ->
Compositor -> Rendering backend

[54th Parallel]

On Thursday, 20 August 2020 at 20:08:10 UTC+8 donoban wrote:

Maybe your problem is Opengl not being hardware accelerated. Try
switching to XRender under System Settings -> Display and Monitor ->
Compositor -> Rendering backend

KDE was already uninstalled when you posted this so I can't test it out, but I'll give it a try next time. Thanks