Bug 413207 - plasma5 logoff and re-login hangs forever
Summary: plasma5 logoff and re-login hangs forever
Status: RESOLVED WORKSFORME
Alias: None
Product: plasmashell
Classification: Plasma
Component: general (show other bugs)
Version: 5.17.0
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: 1.0
Assignee: David Edmundson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-10-19 18:44 UTC by slartibart70
Modified: 2019-11-07 17:18 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
tasks (1.89 KB, text/plain)
2019-10-21 18:54 UTC, slartibart70
Details
tasks2 (2.91 KB, text/plain)
2019-10-21 18:54 UTC, slartibart70
Details
tasks3 (1.66 KB, text/plain)
2019-10-21 18:54 UTC, slartibart70
Details

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Description slartibart70 2019-10-19 18:44:02 UTC
Hi,
since plasma 5.16.x and 5.17.0 (using zawertun copr repo) on fedora30 i very often encounter problems when leaving (using logout) and re-login to plasma.
In 5.16.x i could simply try
systemctl restart sddm.service and re-login successfully. Sometimes an additional 'killall -u <user>' was necessary followed by sddm-restart in a separate root-vterm.

The sysmptoms are:
sddm accepts your password, then the screen goes black with the rotating spinner and the kde/plasma logo in the middle.
Normally, the screen flickers once, then the login succeeds and plasma desktop is available.

When it 'hangs', the flicker is missing and the spinner just goes away, the logo is also gone, just the mouse cursor remains on a black screen. No desktop whatsoever, though...

Since 5.17.0, all is way quicker - even the error situation :-))
But, here a new 'quality' occurrs: plasma does not even clear the screen, the sddm-login with the breeze background picture is still visible, but the password is greyed out (similar to the 'wrong password' situation, but never returning nor loading your desktop)

So, here it helps to (using root-vterm) kill the current Xorg process, killall -u <user>, systemctl restart sddm.service
If you're lucky, then, after a new login-try, your desktop appears again. Sometimes though, not immediately, it takes way more time for plasma to 'think this over' and give you access to your desktop...

i didn't find anything particularly interesting in dmesg/xorg.log, maybe other logs are giving better info?
Any help is appreciated
Comment 1 Rex Dieter 2019-10-19 21:35:55 UTC
I'd encourage you to consider setting
KillUserProcesses=yes
in /etc/systemd/logind.conf to ensure no lingering processes from your previous session are still running after you logout. This has been a primary cause for the symptom(s) you describe in my experience.
Comment 2 David Edmundson 2019-10-20 01:29:32 UTC
~/.local/share/sddm/xorg-session.log please

As well as what Rex says can you switch to a real VT and run ps -u  between sessions
Comment 3 slartibart70 2019-10-21 18:27:44 UTC
thanks for the suggestions,
i added Rex' suggestion, started plasma, started chromium and systemsettings5 and a konsole and did a Ctrl-Alt-Del to logoff.
Next, try to login... and plasma hangs again.

This time, a systemctl restart sddm.service did the trick for the (next) login.
So, maybe the 'hanging' tasks are only part of the story?

Sorry, but on my fc30 system there is no 
 ~/.local/share/sddm/xorg-session.log
(also not when trying to 'find' it starting by /)
Comment 4 slartibart70 2019-10-21 18:38:52 UTC
i checked the user processes when logging off on a root-VTerm (ctrl-alt-F2).
It seems, it takes a while until all user tasks are ended.
So, when waiting until all user tasks are gone, the re-login to plasma seems to work properly
(maybe i was just a bit too impatient?)
Comment 5 slartibart70 2019-10-21 18:53:06 UTC
once again, more info:
- when logging off of plasma, the tasks in attachment 'tasks' are still available/active
- when logging in again, and plasma hangs, the situation is shown in 'tasks2'
- when logging in and the sddm just greys out the password field (and showing the background image forever) we have the situation in 'tasks3'

When i killed -9 the defunct processes of tasks3, a new login was possible.

Maybe, there is still a problem here which is not addressed by the logind setting.
In plasma 5.14? (the default one of fc30) the same problem appeared, but way less often (and with the default setting in logind, all entries commented)
Comment 6 slartibart70 2019-10-21 18:54:16 UTC
Created attachment 123389 [details]
tasks
Comment 7 slartibart70 2019-10-21 18:54:32 UTC
Created attachment 123390 [details]
tasks2
Comment 8 slartibart70 2019-10-21 18:54:46 UTC
Created attachment 123391 [details]
tasks3
Comment 9 Bug Janitor Service 2019-11-05 04:33:10 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 10 slartibart70 2019-11-07 17:18:59 UTC
seems that with the latest plasma 5.17.2 update some (if not all) problems were fixed. At least, i did not encounter the effects described above any more.
Thanks for your help 
*closing this ticket*