Set a positive value to oom_score_adj for session processes

[Jean-Baptiste Lallement]

Reference: bug 1376165

In /etc/init/lightdm.override the oom score adjustment is set to -10. But system processes have an adjustment of 0 which means system processes will be preferred to session process in out of memory conditions.

The score for session processes should be much higher.

I tried the following test case:
- Take a picture with camera
- Copy it 100 times to simulate several shots with the camera.
- Then go to the Photo scope
- tap on "My Pictures"

With the current setting oom killer selects system dbus or powerd which requires a hard reboot of the device.
I tried 300 (this is an example to have a significant difference with current setting) and OOM killer selects unity8-dash (which used 44% of the memory) and the system recovered without a reboot.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: lxc-android-config 0.207 [origin: Ubuntu RTM]
Uname: Linux 3.4.67 armv7l
ApportVersion: 2.14.7-0ubuntu1
Architecture: armhf
Date: Mon Oct 6 11:41:24 2014
InstallationDate: Installed on 2014-09-29 (7 days ago)
InstallationMedia: Ubuntu Utopic Unicorn (development branch) - armhf (20140929-030205)
PackageArchitecture: all
SourcePackage: lxc-android-config
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.init.device.hacks.conf: [modified]
mtime.conffile..etc.init.device.hacks.conf: 2014-09-25T15:57:00
upstart.alsa-restore.override: manual
upstart.alsa-store.override: manual
upstart.boot-hooks: Error: [Errno 21] Is a directory: '/etc/init/boot-hooks'
upstart.cups.override:
 # cups - CUPS Printing spooler and server
 # socket activation overrides for touch
 start on socket PROTO=inet PORT=631 ADDR=127.0.0.1
 exec /usr/sbin/cupsd -f -x 30
upstart.lxc-net.override: manual
upstart.plymouth-upstart-bridge.override: manual
upstart.setvtrgb.override: manual
upstart.ssh.override:
 manual

 exec /usr/sbin/sshd -D -o PasswordAuthentication=no
upstart.tty1.override: manual
upstart.tty2.override: manual
upstart.tty3.override: manual
upstart.tty4.override: manual
upstart.tty5.override: manual
upstart.tty6.override: manual
upstart.ureadahead-other.override: manual
upstart.ureadahead.override: manual

[Oliver Grawert (ogra)]

sigh, indeed the file is in ubuntu-touch-session ... not in lxc-android-config, adjusting bug taslks accordingly

[Oliver Grawert (ogra)]

http://paste.ubuntu.com/8505997/ for reference

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-touch-session - 0.108+14.10.20141006-0ubuntu1

---------------
ubuntu-touch-session (0.108+14.10.20141006-0ubuntu1) utopic; urgency=low

  [ Oliver Grawert ]
  * fix the oom score for the ubuntu-touch session so that the value
    lies above system processes and session processes get killed first.
    (LP: #1377869)
 -- Ubuntu daily release <email address hidden> Mon, 06 Oct 2014 13:48:02 +0000