README.rst

cgroup-tools

DEPRECATION NOTICE:

| These scripts are useless on a modern linux with unified cgroup-v2 hierarchy. | On a systemd-enabled machine, use "systemd-run --scope" instead. | See also: mk-fg/fgtk#cgrc tool <https://github.com/mk-fg/fgtk#cgrc>_

A set of tools to work with cgroup tree and process classification/QoS according to it.

More (of a bit outdated) info can be found in a blog post here <http://blog.fraggod.net/2011/2/cgroups-initialization-libcgroup-and-my-ad-hoc-replacement-for-it>_.

Main script there - cgconf - allows to use YAML like this to configure initial cgroup hierarcy like this::

path: /sys/fs/cgroup

defaults: _tasks: root:wheel:664 _admin: root:wheel:644 # _path: root:root:755 # won't be chown/chmod'ed, if unset freezer:

groups:

# Must be applied to root cgroup
memory.use_hierarchy: 1

# base:
#   _default: true # to put all pids here initially
#   cpu.shares: 1000
#   blkio.weight: 1000

user.slice:
  cpu:
    cfs_quota_us: 1_500_000
    cfs_period_us: 1_000_000

tagged:

  cave:
    _tasks: root:paludisbuild
    _admin: root:paludisbuild
    cpu:
      shares: 100
      cfs_quota_us: 100_000
      cfs_period_us: 250_000
    blkio.weight: 100
    memory.soft_limit_in_bytes: 2G

  desktop:

    roam:
      _tasks: root:users
      cpu.shares: 300
      blkio.weight: 300
      memory.soft_limit_in_bytes: 2G

    de_misc:
      memory.soft_limit_in_bytes: 700M
      memory.limit_in_bytes: 1500M

  vm:
    quasi:
    misc:
      cpu.shares: 200
      blkio.weight: 100
      memory.soft_limit_in_bytes: 1200M
      memory.limit_in_bytes: 1500M

  bench:
    # Subdir for adhoc cgroups created by user
    tmp:
      # Corresponding pw_gid will be used, if "user:" is specified
      # Specs like "user", ":group:770" or "::775" are all valid.
      _tasks: 'fraggod:'
      _admin: 'fraggod:'
      _path: 'fraggod:'
      # These will be initialized as dirs with proper uid/gid, but no stuff applied there
      cpuacct:
      memory:
      blkio:
    # Limits that groups in tmp/ can't transcend
    cpu.shares: 500
    blkio.weight: 500
    memory.soft_limit_in_bytes: 300M
    memory.limit_in_bytes: 500M

And then something like cgrc <tagged-name> <cmd> <args...> to run anything inside these (can also be used in shebang with -s, with cmd from stdin, etc).

Other tools allow waiting for threads within some cgroup to finish before proceeding (cgwait), put stuff running there on hold easily (cgfreeze) and run stuff in temp-cgroup, reporting accounting data for it afterwards (cgtime).

cgconf and cgrc turn out to be surprisingly useful still, despite systemd adding knobs to control cgroup resource limits (but not all of them, and spread over lot of small files, which are pain if you need a big picture of e.g. weights) and systemd-run, which hides i/o of whatever it runs in systemd slices.