VMs based on Fedora template hang for a long time

[Rudd-O]

Qubes OS version R3.2

Affected TemplateVMs: at least fedora-24

Console shows hanging at A stop job is running for Session c1 of user user (...1min 30s...)

It does not happen all the time — most of the time this step takes 5 to 10 seconds tops — but when it does, it waits the full 90 seconds, consuming 100% CPU.

One thing that makes this more likely to be reproduced is to run qvm-start -a [VM] vlc (with VLC from rpmfusion installed in the VM) in order to start the VM, then qvm-shutdown [VM] in another terminal.

Pointers to help me break into the VM as it is shutting down will be most welcome. That way I can provide more debugging info. systemd in debug mode sadly doesn't provide much more information that is valuable in the console while shutting down — it would be nice if it showed which processes exactly it is trying to kill. Would be even nicer if I could run a top (as root, obviously) on another HVC during shutdown, without it getting killed.

[Rudd-O]

One thing that is obvious to me, is that right after "A stop job is running" finishes (whether in 10 seconds or 90 seconds), the kernel message [ time ] u2mfn_release, priv= (null) appears on the same line (as the kernel prints it out, and the cursor is right to the "A stop job" text). Always.

[Rudd-O]

One thing that is obvious to me, is that right after "A stop job is running" finishes (whether in 10 seconds or 90 seconds), the kernel message [ time ] u2mfn_release, priv= (null) appears on the same line (as the kernel prints it out, and the cursor is right to the "A stop job" text). Always.

[marmarek]

u2mfn_release happens when gui-agent is terminated. Also, take a look here: https://freedesktop.org/wiki/Software/systemd/Debugging/#index2h1

[marmarek]

u2mfn_release happens when gui-agent is terminated. Also, take a look here: https://freedesktop.org/wiki/Software/systemd/Debugging/#index2h1

[Rudd-O]

I tried that. None of it worked — I can't break into the system as it shuts down using xl console. Hence my request for help.

[Rudd-O]

I tried that. None of it worked — I can't break into the system as it shuts down using xl console. Hence my request for help.