Extramodules for Zen Kernel

TomZ · August 31, 2020, 7:15am

Well, looks like a bit more than just installing zen is required, at least on my machine.

Had a bit of a panic situation this morning when back at my desk (2 monitor setup) after a week off and the nVidia card wouldn’t load any longer. Turns out that all of my kernel extra modules were missing:

Not a big deal because I am now back on the regular kernel and back in business. But as an eager learner :-), what do I have to do to get all these modules linked to the Zen kernel?

By the way, after running Zen for a week I can’t tell a difference between Zen and the regular kernel.

Hystrix · August 31, 2020, 8:17am

Same here

pebcak · August 31, 2020, 8:26am

see

Here is the result of one benchmark test comparing linux-zen an linux-hardened. My guess is that the result is more or less the same for the other kernels as well

Looking at Hardened - #45 by pebcak

TomZ · September 7, 2020, 5:47pm

Did a bit of research on this but without any luck. Does anyone have an idea why off the three kernels I have installed only one, 5.8.x, has got the extramodules folder?
For LTS to be a true backup kernel I would need all those modules available for LTS as well.

dalto · September 7, 2020, 5:58pm

If you want to use modules for other kernels, you should consider using dkms modules instead. Those will work with most other kernels.

anon31687413 · September 7, 2020, 5:59pm

LTS has nvidia modules ready-built, vbox should be taken care of by dkms.
(PS: I don’t even have extramodules folder on vanilla 5.8, lol)

TomZ · September 7, 2020, 6:04pm

Thanks guys, I need to read up on this some more, switching to dkms seems like a pretty fundamental change which I need to better understand before I ruin my current install

nVidia and vBOX seem to be covered, last one I need is bbswitch.

dalto · September 7, 2020, 6:04pm

I think you will find it mostly just works if you install the relevant dkms packages.

anon31687413 · September 7, 2020, 6:09pm

bbswitch has a dkms package: https://www.archlinux.org/packages/community/x86_64/bbswitch-dkms/

TomZ · September 7, 2020, 6:12pm

Yes, indeed. So I guess I need the base dkms package (#1), nVidia (#2), bbswitch (#5) and the two vBox packages (#11 and #12)

No need to remove the existing modules or reconfigure any config files?

anon31687413 · September 7, 2020, 6:13pm

You only need vbox-host (12) on the host.

You’ll probably run into a conflict when installing the dkms packages, telling you to remove the prebuilt modules.

TomZ · September 7, 2020, 6:14pm

Excellent! On it now…

Looks good so far! Now a reboot with LTS…

==> dkms install --no-depmod -m vboxhost -v 6.1.12_OSE -k 5.8.7-arch1-1
==> dkms install --no-depmod -m bbswitch -v 0.8 -k 5.8.7-zen1-1-zen
==> dkms install --no-depmod -m nvidia -v 450.66 -k 5.4.63-1-lts
==> dkms install --no-depmod -m nvidia -v 450.66 -k 5.8.7-zen1-1-zen
==> dkms install --no-depmod -m bbswitch -v 0.8 -k 5.4.63-1-lts
==> dkms install --no-depmod -m nvidia -v 450.66 -k 5.8.7-arch1-1

Good news! Module version 450.66 for nvidia.ko.xz
exactly matches what is already found in kernel 5.8.7-arch1-1.
DKMS will not replace this module.
You may override by specifying --force.

Good news! Module version 450.66 for nvidia-modeset.ko.xz
exactly matches what is already found in kernel 5.8.7-arch1-1.
DKMS will not replace this module.
You may override by specifying --force.

Good news! Module version 450.66 for nvidia-drm.ko.xz
exactly matches what is already found in kernel 5.8.7-arch1-1.
DKMS will not replace this module.
You may override by specifying --force.
==> dkms install --no-depmod -m vboxhost -v 6.1.12_OSE -k 5.4.63-1-lts
==> dkms install --no-depmod -m vboxhost -v 6.1.12_OSE -k 5.8.7-zen1-1-zen
==> dkms install --no-depmod -m bbswitch -v 0.8 -k 5.8.7-arch1-1
==> depmod 5.8.7-arch1-1
==> depmod 5.4.63-1-lts
==> depmod 5.8.7-zen1-1-zen

anon31687413 · September 7, 2020, 6:25pm

I think you’re fine

TomZ · September 7, 2020, 6:31pm

I am indeed, all services up and running with the LTS kernel. That was indeed a lot easier than expected!
Thanks for helping along

$ sudo dkms status
bbswitch, 0.8, 5.4.63-1-lts, x86_64: installed
bbswitch, 0.8, 5.8.7-arch1-1, x86_64: installed
bbswitch, 0.8, 5.8.7-zen1-1-zen, x86_64: installed
nvidia, 450.66, 5.4.63-1-lts, x86_64: installed
nvidia, 450.66, 5.8.7-arch1-1, x86_64: installed (original_module exists) (WARNING! Diff between built and installed module!) (WARNING! Diff between built and installed module!) (WARNING! Diff between built and installed module!)
nvidia, 450.66, 5.8.7-zen1-1-zen, x86_64: installed
vboxhost, 6.1.12_OSE, 5.4.63-1-lts, x86_64: installed
vboxhost, 6.1.12_OSE, 5.8.7-arch1-1, x86_64: installed
vboxhost, 6.1.12_OSE, 5.8.7-zen1-1-zen, x86_64: installed

According to this https://wiki.archlinux.org/index.php/Dynamic_Kernel_Module_Support upgrades seem to take care of themselves as well.

Is there anything else I need to know as a fresh dkms user?

anon31687413 · September 7, 2020, 6:38pm

Well if you don’t need any other extramodules, and use only the dkms packages and kernels that come directly from the repos, then I think you don’t have to worry.

dkms can sometimes get complicated if you 1) use a custom kernel, 2) use clang compiler and 3) want to sign your extramodules.

EDIT: semi off-topic:
Funnily enough, in some cases (custom kernel) you can have both dkms and the extramodule installed, in which case the extramodule takes precedence.

TomZ · September 8, 2020, 7:09am

Looks like there is a bit more to dkms, as this morning when I put my laptop in it’s dock my primary screen, which is attached via the nVidia card, goes dark after a few minutes?
In fact, both screens will go dark for a second and then only the secondary screen will come back.
Rebooted twice now with the same results. Nothing obvious in journalctl.

The strange thing is that I can see a cursor, and the cursor will move on both screens in parallel but none of the application windows on the primary screens show. I can try to drag them over to the working second screen and will catch one by chance.
Maybe it’s Plasma or X which is struggling with the screen reset…

Coincidentally a new nVidia dkms driver arrived this morning so maybe this bug is because of the new nVidia driver and not the switch to dkms. I’ll report back once I know more.

Update: Had a few more crashes yesterday, some so bad that I couldn’t even rescue the machine with REISUB. After another bad one this morning I decided to roll back step by step, starting with the nVidia driver.
Installed the standard nVidia driver and didn’t have a crash all morning. Yesterday I was able to reliably crash the machine just be plugin in a USB device. Today things seem to be back to normal.

Interestingly yay didn’t ask me if I want to replace the dkms driver but simply installed. Means I don’t even know what I am running now? Is there a way to determine if I am running dkms or standard driver?