Gnome/gdm startup apps: Why are some children of gdm and others children of init?

sixerjman · 07-03-2009, 09:58 AM

I am curious to know why some of the applications listed in the gnome 'Startup applications' are children of x-session-manager and others have the init task (PID #1) as the parent PID:

Code:

/usr/sbin/gdm
root      4106  4101  0 10:30 ?        00:00:00     /usr/sbin/gdm
root      4111  4106 13 10:30 tty7     00:01:47       /usr/bin/X :0 -audit 0 -auth /var/lib/gdm/:0.Xauth -nolisten tcp vt7
1000      5054  4106  0 10:30 ?        00:00:00       x-session-manager
1000      5315  5054  0 10:30 ?        00:00:00         /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with-session /usr/bin/seahorse-agent --execute x-session-manager
1000      5364  5054  0 10:30 ?        00:00:00         /usr/bin/seahorse-agent --execute x-session-manager
1000      5608  5054  0 10:30 ?        00:00:04         /usr/bin/metacity
1000      5610  5054  1 10:30 ?        00:00:10         gnome-panel
1000      5612  5054  0 10:30 ?        00:00:00         gnome-volume-control-applet
root      5613  5054  0 10:30 ?        00:00:02         /usr/sbin/firestarter --start-hidden
1000      5614  5054  0 10:30 ?        00:00:00         gksu gnome-system-log
root      5627  5614  0 10:30 ?        00:00:04           gnome-system-log
1000      5615  5054  0 10:30 ?        00:00:01         python /usr/bin/hp-systray
1000      6023  5615  0 10:31 ?        00:00:00           python /usr/bi/hp-systray
1000      6025  6023  0 10:31 ?        00:00:00             python /usr/bin/hp-systray
1000      5618  5054  0 10:30 ?        00:00:00         gnome-power-manager
1000      5620  5054  0 10:30 ?        00:00:00         update-notifier
1000      5621  5054  0 10:30 ?        00:00:00         kerneloops-applet
1000      5622  5054  1 10:30 ?        00:00:10         nautilus -n
...
<*snip*>
...
1000      5603     1  0 10:30 ?        00:00:01   gnome-keyring-daemon --start
1000      5625     1  0 10:30 ?        00:00:00   /usr/lib/bonobo-activation/bonobo-activation-server --ac-activate --ior-output-fd=18
1000      5628     1  0 10:30 ?        00:00:00   /usr/lib/gnome-volume-manager/gnome-volume-manager --sm-disable

I just noticed this after reinstalling 'gnome-volume-manager', which has an entry that specifies '--sm-disable' (don't connect to session manager). Other apps like
pulseaudio and gnome-keyring-daemon are standalone daemons, so that would explain them not being children of the session manager.

I guess I would like to understand the whole process of gnome starting the startup apps from the standpoint of OS process creation (fork w/wout exec, clone, etc.) and
session management.

catkin · 07-04-2009, 10:48 AM

Hello sixerjman

How about this for a plausible hypothesis?

It's set up that way to provide automatic process termination on various events:

children of PID 1 are daemons (a.k.a servers) that should terminate on system shutdown.
children of gdm should terminate when X terminates.
children of gdm-session-manager should terminate when the user session terminates.

Best

Charles