Multiseat fails after reboot

adomas · Posted: Sun Feb 18, 2018 10:43 pm Post subject: Multiseat fails after reboot

Hello,
I have switched from Arch to Gentoo and I am unable to configure Multiseat setup on my system properly.

About my system:
I have two GPUs, GPU-0 is GTX 1080 Ti and used for seat0, GPU-1 is GTX 780 and used for seat1. I have two sets of input assigned to each seat via loginctl. I use ~amd64 Gentoo with OpenRC + elogind.

I manage to get Multiseat working, but after reboot it does not work anymore.

What I do:
1) Using loginctl I attach stuff to seat1
2) I generate xorg.conf file with nvidia-settings making a second X Screen on GPU-1
3) At this point second monitor turns on and shows sddm, I can log in and use seat1
4) I reboot the system and seat1 does not work anymore, also seat0 has glitches at this point
5) Deleting xorg.conf and restarting elogind or sddm disables seat1
6) Again I generate a new xorg.conf with nvidia-settings and everything works until reboot

At the point 4) when system is rebooted and xorg.conf is still there, I get loads of stuff going to /var/log/sddm.log and it reaches hundreds of megabytes in size.

In sddm.log I see these lines looping:

Zucca · Posted: Sun Feb 18, 2018 11:30 pm Post subject:

Back when I had GPU on MB and seperate GPU I used to have a multiseta setup.
What I had different was that back then I used systemd as init and I used lightdm as display manager.

If it's not too much of a hassle, try out lightdm. If it works, then sddm has a bug or there's something wrong on your sddm configs.
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Gentoo IRC channels reside on Libera.Chat.
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adomas · Posted: Sun Feb 18, 2018 11:44 pm Post subject:

Well same version of sddm (0.17.0) worked well on Arch. Might be something wrong with sddm.conf, but everything seems to be normal:

Zucca · Posted: Mon Feb 19, 2018 1:18 am Post subject:

adomas · Posted: Mon Feb 19, 2018 1:53 am Post subject:

Well the problem is Xorg Screen 1 dies as you can see from my Xorg.1.log, that is the reason sddm gets crazy retrying to launch Xorg.

I'm unsure but I think there is no problem with sddm, as sddm-helper does not exit.

At the moment I think it's something with xorg.conf, just unsure what. As I boot-up I let xorg detect stuffs by itself, and later I put xorg.conf to turn on the second Xorg server... It works like it should until reboot.

Checked the the link, I think it is not relevant...

Maybe it's problem with OpenRC? On Arch I had systemd and it worked well with same package versions.

Zucca · Posted: Mon Feb 19, 2018 10:37 am Post subject:

adomas · Posted: Mon Feb 19, 2018 5:39 pm Post subject:

I suspected that is OpenRC problem because of this article:

https://wiki.gentoo.org/wiki/Comparison_of_init_systems

In section "Supported services (in Gentoo)" I see that "X11 Display Manager setup" for OpenRC is "Single service for all (required to auto-restart)."
Somehow I'm unsure what does that mean, but I was thinking maybe it's about that only one DM can run from init? In systemd it says "Separate DM units."

Well about xorg.conf I think you are correct. I need to try to strip down as much as possible and let Xorg autodetect settings. I will try this right now

About that NVRM thing, it was always there, it does not depend on distro even. I always was seeing it on all Linux distros I have ran. It is because of NVIDIA proprietary drivers.

About nvidia-xconfig I can't use it, as it setups always only one Xorg Server and one Display. And yes it generates xorg.conf file

I use graphical nvidia-settings and make a second GPU with a second Monitor to have a separate Xorg server...

I could do a script which moves around xorg.conf, and I think it would work, but it feels like a very dirty solution to me.

I hope stripping xorg.conf to minimum will help out.

Thanks Zucca for helping, if you have any more ideas, I'm interested.

Zucca · Posted: Mon Feb 19, 2018 6:02 pm Post subject:

I'd stick a second GPU into my PC if I had space left. :( µATX motherboards have their limits.

Anyway OpenRC should not matter. Your session/login -manager is what matters. You have elogind, and it should be no problem then.
Can you succesfully run multiseat if you change to software OpenGL renderer (elselect opengl list)?
_________________
..: Zucca :..
Gentoo IRC channels reside on Libera.Chat.
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adomas · Posted: Tue Feb 20, 2018 2:23 pm Post subject:

With a software renderer was same problem. I have tried stripping down the xorg.conf to minimum, and got pretty weird results, as seat1 input was for Screen 0 and seat0 input did nothing as Screen 1 was off in a Xorg start-up loop.

Anyway I found sort of solution. I removed nouveau from blacklist and rebooted without xorg.conf and everything just did work as I would like. But as one of my GPUs is GTX 1080 Ti which is pretty new and not well supported by nouveau, I have pretty severe performance issues at least on seat0.

So the point is that NVIDIA proprietary drivers makes this a problem. I'm unsure how to proceed. I was few days already, I really need to get this seat1 working at full speed, as my wife wants to use it for graphics works.

I will try lightdm now.

EDIT: lightdm did not work at all with my configuration...

Zucca · Posted: Tue Feb 20, 2018 2:43 pm Post subject:

adomas · Posted: Tue Feb 20, 2018 2:46 pm Post subject:

Well lightdm did not work at all...

I'm lost and unsure what to try next.

I was using same version of NVIDIA drivers on Arch and everything worked.

Zucca · Posted: Tue Feb 20, 2018 2:58 pm Post subject:

n17r4m · n00b Joined: 22 Jan 2018 Posts: 23

Just throwing my 2 cents in, since I am running a very similar config as yours..

Often times there was trouble with one or both of the multi-seats not being brought up in a manner very similar to what is happening to you, however after setting up multi-seat, if after a reboot the display's refused to come up, changing the physical port the monitor was connected to in the back of the machine to one next to it (same card, different port), the problem fully resolved itself, and good behavior persisted across reboots. *shrugs* just something kinda non-intuitive that you may want to try,

Nreal · Apprentice Joined: 06 Jan 2009 Posts: 265

Still have kdm as login manager, have not been able to upgrade the system for a long while.. Stupid thing replacing kdm with alpha sddm... just saying..

Hu · Moderator Joined: 06 Mar 2007 Posts: 21607

Nreal · Apprentice Joined: 06 Jan 2009 Posts: 265

Zucca · Posted: Thu Apr 05, 2018 8:33 am Post subject:

Nreal · Apprentice Joined: 06 Jan 2009 Posts: 265

Not sure if nouveau drivers work with games like minecraft and some steam games. In my setup theres 2 seats with nvidia and one intel hd graphics for www browsing. Havent had any luck with Lightdm, i have xorg conf for all 3 seats, and it has worked like the toilets in trains for ages with kdm..