[LightDM] [systemd-devel] sd 221 regression: login - nonexistent sessions via lightdm

[Martin Pitt]

Hello David,

David Herrmann [2015-07-07 19:10 +0200]:
> On Tue, Jul 7, 2015 at 6:55 PM, Martin Pitt <martin.pitt at ubuntu.com> wrote:
> > It's not that simple to reproduce, but sometimes it seems the lightdm
> > "greeter" session (running as user lightdm, where you select user/type
> > password and so on) doesn't completely terminate, but some processes
> > stay around in it. Thus the greeter session stays around in state
> > "Closing", and then the "real" session starts on the same VT.
> >
> > I asked the reporter of https://launchpad.net/bugs/1472259 to attach
> > systemd-cgls, so that we can see what's running in the session.

Got that now:

 └─user-110.slice
    ├─user at 110.service
    │ ├─996 /lib/systemd/systemd --user
    │ └─997 (sd-pam)
    └─session-c1.scope
      ├─1149 /usr/bin/pulseaudio --start --log-target=syslog
      └─1168 /usr/lib/pulseaudio/pulse/gconf-helper

So indeed some leaked processes which don't terminate along with
gnome-session. As it happens I get that on my system as well, but the
"leaked" session just lasts for a few seconds after logging in and
then goes away.

> So it might indeed just be a race in lightdm.

Right, it's IMHO a lightdm greeter bug that the session doesn't
properly terminate.

> Anyway, this patch here should also fix the issue (if it does, I'll
> commit something proper).

Thanks, looks good! It's surely a workaround, but indeed this might
not be the only case that's affected, so thanks for this safety net.
I'll build a package with that and ask the reporter for testing.

Martin
-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)