1. #!/bin/sh
    2. # Copyright 2011 Canonical, Inc
    3. #           2014 Tianon Gravi
    4. # Author: Serge Hallyn <serge.hallyn@canonical.com>
    5. #         Tianon Gravi <tianon@debian.org>
    6. set -e
    7. # for simplicity this script provides no flexibility
    8. # if cgroup is mounted by fstab, don't run
    9. # don't get too smart - bail on any uncommented entry with 'cgroup' in it
    10. if grep -v '^#' /etc/fstab | grep -q cgroup; then
    11.     echo 'cgroups mounted from fstab, not mounting /sys/fs/cgroup'
    12.     exit 0
    13. fi
    14. # kernel provides cgroups?
    15. if [ ! -e /proc/cgroups ]; then
    16.     exit 0
    17. fi
    18. # if we don't even have the directory we need, something else must be wrong
    19. if [ ! -d /sys/fs/cgroup ]; then
    20.     exit 0
    21. fi
    22. # mount /sys/fs/cgroup if not already done
    23. if ! mountpoint -q /sys/fs/cgroup; then
    24.     mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
    25. fi
    26. cd /sys/fs/cgroup
    27. # get/mount list of enabled cgroup controllers
    28. for sys in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
    29.     mkdir -p $sys
    30.     if ! mountpoint -q $sys; then
    31.   if ! mount -n -t cgroup -o $sys cgroup $sys; then
    32.       rmdir $sys || true
    33.   fi
    34.     fi
    35. done
    36. # example /proc/cgroups:
    37. #  #subsys_name    hierarchy    num_cgroups    enabled
    38. #  cpuset    2    3    1
    39. #  cpu    3    3    1
    40. #  cpuacct    4    3    1
    41. #  memory    5    3    0
    42. #  devices    6    3    1
    43. #  freezer    7    3    1
    44. #  blkio    8    3    1
    45. # enable cgroups memory hierarchy, like systemd does (and lxc/docker desires)
    46. # https://github.com/systemd/systemd/blob/v245/src/core/cgroup.c#L2983
    47. # https://bugs.debian.org/940713
    48. if [ -e /sys/fs/cgroup/memory/memory.use_hierarchy ]; then
    49.     echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy
    50. fi
    51. exit 0