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[Glyn Normington <gnormington@xxxxxxxxxxxxx>]

This is not a bug.

It turns out the behaviour I was seeing was due to the fact that swap
accounting is disabled by default and so the perl process was swapping
rather than being killed when its RAM limit was reached.

If I turn swap off (swapoff -a), the process is killed correctly.
Similarly, if I inhibit swapping by setting memory.swappiness to 0 in
the "example" cgroup, the process is killed correctly.

Alternatively, if I turn swap accounting on (by setting
`GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"` in
/etc/default/grub, running update-grub, and rebooting), then
memory.memsw.* files appear in the "example" cgroup. If I set
memory.limit_in_bytes and memory.memsw.limit_in_bytes both to 3000000,
then the perl process is killed correctly.

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https://bugs.launchpad.net/bugs/1303683

Title:
  Memory resource controller oom killing not functioning

Status in “linux” package in Ubuntu:
  Invalid

Bug description:
  This problem reproduces on Ubuntu 13.10 with a 3.11 kernel but, for
  comparison, works ok on RHEL 7 with a 3.10 kernel.

  Steps to reproduce:

  1. Make a directory, for example /home/glyn/cgh1.
  2. Switch to root user.
  3. Attach the memory resource controller subsystem to a cgroup hierarchy:

  # mount -t cgroup -o memory none /home/glyn/cgh1

  4. cd /home/glyn/cgh1

  5. Createa a child cgroup:

  # mkdir example

  6. cd example

  7. check oom killing is enabled:

  # cat memory.oom_control 
  oom_kill_disable 0
  under_oom 0

  8. Set a memory limit for the example cgroup of approx. 1 MB:

  # echo 1000000 > memory.limit_in_bytes 
  # cat memory.limit_in_bytes 
  1003520

  9. Move the current process into the example cgroup and check it has
  moved:

  # echo $$ > tasks
  # cat tasks
  7357
  8449
  # cat tasks
  7357
  8450

  10. Run a process which will exceed 1 MB of memory:

  # perl -e 'for ($i = 0; $i < 10; $i++) { $foo .= "A" x (1024 * 1024); }'
  #

  This terminates successfully whereas it should have been killed. On
  RHEL 7 (and on earlier Ubuntu versions I have tried), the results look
  like this:

  # perl -e 'for ($i = 0; $i < 10; $i++) { $foo .= "A" x (1024 * 1024); }'
  killed
  #

  I will attempt to reproduce this bug on an upstream kernel, but don't
  want to lose the bug report during the upgrade, hence I am filing the
  report now.

  ProblemType: Bug
  DistroRelease: Ubuntu 13.10
  Package: linux-image (not installed)
  ProcVersionSignature: Ubuntu 3.11.0-17.31-generic 3.11.10.3
  Uname: Linux 3.11.0-17-generic x86_64
  ApportVersion: 2.12.5-0ubuntu2.2
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  glyn       1587 F.... pulseaudio
  Date: Mon Apr  7 10:16:24 2014
  HibernationDevice: RESUME=UUID=18692506-8752-46bb-8b44-1fb2f0ba5e03
  InstallationDate: Installed on 2014-03-05 (32 days ago)
  InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
  IwConfig:
   eth0      no wireless extensions.
   
   lo        no wireless extensions.
   
   docker0   no wireless extensions.
  Lsusb:
   Bus 001 Device 004: ID 80ee:0021 VirtualBox USB Tablet
   Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  MachineType: innotek GmbH VirtualBox
  MarkForUpload: True
  ProcEnviron:
   LANGUAGE=en_GB:en
   TERM=xterm
   PATH=(custom, no user)
   LANG=en_GB.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 VESA VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-17-generic root=UUID=24214f2e-a703-46ea-9fdd-0f64e110b628 ro quiet splash vt.handoff=7
  PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions:
   linux-restricted-modules-3.11.0-17-generic N/A
   linux-backports-modules-3.11.0-17-generic  N/A
   linux-firmware                             1.116.2
  RfKill:
   
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 12/01/2006
  dmi.bios.vendor: innotek GmbH
  dmi.bios.version: VirtualBox
  dmi.board.name: VirtualBox
  dmi.board.vendor: Oracle Corporation
  dmi.board.version: 1.2
  dmi.chassis.type: 1
  dmi.chassis.vendor: Oracle Corporation
  dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr:
  dmi.product.name: VirtualBox
  dmi.product.version: 1.2
  dmi.sys.vendor: innotek GmbH

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