Arch Linux

ArthurBorsboom

Member

Registered: 2014-05-20

Posts: 56

systemd-logind: failed to get session: PID xxx does not belong to any

On my 3 Arch systems I always have an error in my Xorg.0.log and if the computer has two video cards, also in Xorg.8.log.
The error message is the following, where the PID varies.

(EE) systemd-logind: failed to get session: PID 385 does not belong to any known session

This has an effect on my usage of Bumblebee, however this error message also appears on a system without Bumblebee and with only one video card.
I have the feeling this error also has an effect on the auto-login feature of SDDM.

I am not sure what causes this issue and I like to dig into it. I believe the following components are the 'involved' ones.

• kernel

• systemd, in particular systemd-logind

• xorg

• sddm

• lxqt

How would you suggest to debug this issue?

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,721

Re: systemd-logind: failed to get session: PID xxx does not belong to any

After this error occurs, does the referenced PID show up in ps -ef  ?  If so, what is the line from that output that references that PID?

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How to Ask Questions the Smart Way

ArthurBorsboom

Member

Registered: 2014-05-20

Posts: 56

Re: systemd-logind: failed to get session: PID xxx does not belong to any

The proces it refers to is:

/usr/bin/Xorg.bin :0 -auth /var/run/sddm/:0 -nolisten tcp -background none -noreset vt1

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,721

Re: systemd-logind: failed to get session: PID xxx does not belong to any

How do you start Xorg?

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Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
The shortest way to ruin a country is to give power to demagogues.— Dionysius of Halicarnassus
---
How to Ask Questions the Smart Way

ArthurBorsboom

Member

Registered: 2014-05-20

Posts: 56

Re: systemd-logind: failed to get session: PID xxx does not belong to any

Although not sure about the exact way, I do know that I have enabled SDDM as a systemd service.

My guess is that SDDM starts Xorg.

nbvcxz

Member

From: Poland

Registered: 2007-12-29

Posts: 202

Re: systemd-logind: failed to get session: PID xxx does not belong to any

Got very similar problem, with "fresh" install on Lenovo G50 laptop: Intel and Ati cards. I noticed using sftp transfer or conky's curl I am logged out from my session back to lightdm.
From dmesg:

[  966.843057] Chrome_ChildThr[1348]: segfault at 0 ip 00007f88d9d36391 sp 00007f88c5a8d500 error 6 in libmozalloc.so[7f88d9d35000+2000]

and Xorg.log

[  1209.395] (EE) systemd-logind: failed to get session: PID 1955 does not belong to any known session
[  1209.398] (EE) Failed to load module "modesetting" (module does not exist, 0)
[  1209.398] (EE) Failed to load module "fbdev" (module does not exist, 0)
[  1209.398] (EE) Failed to load module "vesa" (module does not exist, 0)

Is it something similar to this bug? Anything else seems to work OK.

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Lenovo G50 | LXQT-git | compton | conky

cro

Member

From: Germany

Registered: 2006-01-02

Posts: 101

Re: systemd-logind: failed to get session: PID xxx does not belong to any

Same problem here, starting Xorg through kdm service.

/var/log/Xorg.0.log:

[     6.193] (EE) systemd-logind: failed to get session: PID 1030 does not belong to any known session

ps -ef:

root      1030  1014  9 13:20 tty7     00:06:49 /usr/lib/xorg-server/Xorg :0 vt7 -nolisten tcp -auth /var/run/xauth/A:0-OesD8b

Should I be concerned about this error message? I currently not sure if it impacts something for me.

Sanne

Member

Registered: 2012-03-13

Posts: 87

Re: systemd-logind: failed to get session: PID xxx does not belong to any

I was just researching the issue as I get the same systemd-logind message in my Xorg log, everything seems to work though. I found an explanation in the Red Hat bug tracker, looks like the message can be ignored:

Starting with F-21 Xorg can talk to systemd-logind to get filedescriptors for the gpu and input devices from systemd-logind.
...
systemd-logind will refuse any requests to do so unless Xorg is started from a properly registered login session. Currently all display managers such as gdm, xdm, etc. do not set up a proper login session in which to start X, leading to this error. This error can be safely ignored, as Xorg is still capable of opening the devices itself.

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ValadeA

Member

Registered: 2015-08-16

Posts: 4

Re: systemd-logind: failed to get session: PID xxx does not belong to any

I got the same error message when launching optirun, but in my case, optirun couldn't acutally run. I guess I solved this problem by opening /etc/bumblebee/bumblebee.conf and switching TurnCardOffAtExit to true (which was set at false by default). Maybe I did wrong, but it works correctly since then...