GNOME Bugzilla – Bug 652289
GDM Endlessly Writes to Saved_State Causing Failure
Last modified: 2012-02-21 22:52:25 UTC
Created attachment 189630 [details]
the saved_state file sitting in the .gconfd folder of $HOME for gdm
A certain unknown event is triggering gdm to write to saved_state over and over again. As new users attempt to authenticate their temporary gdm gconfd session is attemping to read in this file and leak horribly. Each new users gets a bigger and bigger memory footprint. Eventually the server becomes unusable.
Attaching the last 4000 lines of the saved_state file.
Ours had grown to almost 6GB before the server was rebooted.
Once I moved the file out of the way and killed the errant gdm's, the problem went away.
saved_state is gconf actually, moving
so i can't claim to know exactly why the saved_state file is growing to 6GB, but I do know from reading through the code that the saved_state file is not really designed to be written to by multiple gconfd's at the same time. Each one will stomp on the others toes, causing unexpected weirdness. It could very well be that the "stomping" makes stale entries stick around causing the file to grow without bound (although from quickly looking I can't quite see how)
I'll attach some patches to make saved_state per-session instead of per-user like the rest of gconfd is.
Created attachment 189700 [details] [review]
daemon: store saved_state in daemon dir not ~/.gconfd
The daemon dir isn't always ~/.gconfd so we shouldn't hard
Created attachment 189701 [details] [review]
daemon: store daemon data in XDG_RUNTIME_DIR
If XDG_RUNTIME_DIR is available it's a much better
directory than /tmp since it ensures there's no
Created attachment 189702 [details] [review]
daemon: tie saved_state file to session
The code isn't really designed to work well with multiple
gconfd's writing to the same saved_state file, so we should
make it per-session.
Did these patches work for you okay, Dave?
Ray - this is the downstream bug, no final conclution is reached there either.
Err - what if I included the link - sorry
I would still appreciate feedback on these patches if you've had a chance to try them.
Reopening as I can't see any open non-developer question.
I talked to Dave about these today. He said they've been working okay (though he has som cronscripts to clean things up that might not making testing 100% pristine.
I'll probably push these soon.
It's less important now that we don't use ORBit by default, but pushed
anyway to get it off my radar.
Attachment 189700 [details] pushed as ea68943 - daemon: store saved_state in daemon dir not ~/.gconfd
Attachment 189701 [details] pushed as 2895a09 - daemon: store daemon data in XDG_RUNTIME_DIR
Attachment 189702 [details] pushed as 14176e6 - daemon: tie saved_state file to session