Comment 22 for bug 2020641

Daniel,

Thanks for chiming in.

I've tried reproducing this bug outside of DCV, but no lucky.

What I tried last is to launch a baremetal instance on AWS (g4dn.metal) with the same Nvidia GPUs as the instance type where we are consistently able to reproduce this problem, and then I:

1. Installed KVM
2. Created a Jammy VM (just to see if I would be able to reproduce it, and then I would do the same for Lunar)
3. Added an Nvidia GPU to the VM with PCI passthrough
4. Installed the nvidia driver
5. Setup desktop with Xorg (and gdm3 with Xorg) the same way we've been doing with the AWS VM
6. Tried to reproduce the problem by installing skype snap or running 'sudo udevadm trigger'

However, I'm unable to reproduce this problem, even in a Jammy VM (when not using DCV).

You mentioned "then simply verifying the patch is present would suffice", how would I do that? Just showing tha gdm3 from -proposed is enough?

If so, I did setup a Lunar VM the same way (also with the same Nvidia GPU) and did the basic tests:

One thing to notice is that "apt install gdm3" wouldn't upgrade the package to the one in -proposed:

https://pastebin.ubuntu.com/p/FDdFfcPHDd/

So, I had to specify the version:

https://pastebin.ubuntu.com/p/Kq7Zj9wxH2/

Not sure if this is a problem.

Anyway, after that I rebooted the VM and did the basic tests:

Packages installed from -proposed:

https://pastebin.ubuntu.com/p/ZTxYTSQD3v/

- Logged in as ubuntu user and launched Firefox, LibreOffice and gedit:

https://pastebin.ubuntu.com/p/xBJXTG6NgP/

- Switched user to fabiomirmar and opened Thunderbird, skype and gnome-calculator:

https://pastebin.ubuntu.com/p/RSCxqCGcrH/

- Switched back to the ubuntu user and I see its apps are still running:

https://pastebin.ubuntu.com/p/j4kBKF3bXp/

- Once again, switched back to fabiomirmar, and the processes are also running:

https://pastebin.ubuntu.com/p/q9TJFJhQgp/

Also tested the "init 3" / "init 5" tests you mentioned. After the tests mentioned above, I switched to multi-user.target:

https://pastebin.ubuntu.com/p/VkrkdwXcbt/

Then went back to graphical.target:

https://pastebin.ubuntu.com/p/7X8VyydPGz/

Another feedback that I have to share, is that although it's not consistent, on Lunar sometimes the session (gnome?) crashes when you are logging back in after switching user. i.e.: you login as ubuntu, open one or more apps (such as firefox), hit "switch user" and try to login again. Most of the times, it will work and firefox will be running, but sometimes the session crashes and you are brought back to gdm and have to login again. After logging back in, Firefox is no longer there. The logs during the crash are available here:

https://pastebin.ubuntu.com/p/bfRQnrhFNG/

However, I don't think this is related to the GDM patch from Ghadi, as I'm able to reproduce the very same problem with gdm from lunar/main from a fresh installation:

https://pastebin.ubuntu.com/p/bSH7mwVTtB/

I think this might need its own launchpad bug, but leaving my comment with the details here, so that others can share their feedback. Also, not marking this as verification-done for lunar, but I think it's done :)

Regards,
Fabio Martins