SYSTEMD.RESOURCE-CONTROL(5)systemd.resource-controlSYSTEMD.RESOURCE-CONTROL(5)NAMEsystemd.resource-control - Resource control unit settings
SYNOPSIS
slice.slice, scope.scope, service.service, socket.socket, mount.mount,
swap.swap
DESCRIPTION
Unit configuration files for services, slices, scopes, sockets, mount
points, and swap devices share a subset of configuration options for
resource control of spawned processes. Internally, this relies on the
the Control Groups kernel concept for organizing processes in a
hierarchial tree of named groups for the purpose of resource
management.
This man page lists the configuration options shared by those six unit
types. See systemd.unit(5) for the common options of all unit
configuration files, and systemd.slice(5), systemd.scope(5),
systemd.service(5), systemd.socket(5), systemd.mount(5), and
systemd.swap(5) for more information on the specific unit configuration
files. The resource control configuration options are configured in the
[Slice], [Scope], [Service], [Socket], [Mount], or [Swap] sections,
depending on the unit type.
See the New Control Group Interfaces[1] for an introduction how to make
use of resource control APIs from programs.
OPTIONS
Units of the types listed above can have settings for resource control
configuration:
CPUAccounting=
Turn on CPU usage accounting for this unit. Takes a boolean
argument. Note that turning on CPU accounting for one unit might
also implicitly turn it on for all units contained in the same
slice and for all its parent slices and the units contained
therein.
CPUShares=weight
Assign the specified overall CPU time share weight to the processes
executed. Takes an integer value. This controls the "cpu.shares"
control group attribute, which defaults to 1024. For details about
this control group attribute, see sched-design-CFS.txt[2].
Implies "CPUAccounting=true".
MemoryAccounting=
Turn on process and kernel memory accounting for this unit. Takes a
boolean argument. Note that turning on memory accounting for one
unit might also implicitly turn it on for all units contained in
the same slice and for all its parent slices and the units
contained therein.
MemoryLimit=bytes
Specify the limit on maximum memory usage of the executed
processes. The limit specifies how much process and kernel memory
can be used by tasks in this unit. Takes a memory size in bytes. If
the value is suffixed with K, M, G or T, the specified memory size
is parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with
the base 1024), respectively. This controls the
"memory.limit_in_bytes" control group attribute. For details about
this control group attribute, see memory.txt[3].
Implies "MemoryAccounting=true".
BlockIOAccounting=
Turn on Block IO accounting for this unit. Takes a boolean
argument. Note that turning on block IO accounting for one unit
might also implicitly turn it on for all units contained in the
same slice and all for its parent slices and the units contained
therein.
BlockIOWeight=weight
Set the default overall block IO weight for the executed processes.
Takes a single weight value (between 10 and 1000) to set the
default block IO weight. This controls the "blkio.weight" control
group attribute, which defaults to 1000. For details about this
control group attribute, see blkio-controller.txt[4].
Implies "BlockIOAccounting=true".
BlockIODeviceWeight=device weight
Set the per-device overall block IO weight for the executed
processes. Takes a space-separated pair of a file path and a weight
value to specify the device specific weight value, between 10 and
1000. (Example: "/dev/sda 500"). The file path may be specified as
path to a block device node or as any other file in which case the
backing block device of the file system of the file is determined.
This controls the "blkio.weight_device" control group attribute,
which defaults to 1000. Use this option multiple times to set
weights for multiple devices. For details about this control group
attribute, see blkio-controller.txt[4].
Implies "BlockIOAccounting=true".
BlockIOReadBandwidth=device bytes, BlockIOWriteBandwidth=device bytes
Set the per-device overall block IO bandwidth limit for the
executed processes. Takes a space-separated pair of a file path and
a bandwidth value (in bytes per second) to specify the device
specific bandwidth. The file path may be a path to a block device
node, or as any other file in which case the backing block device
of the file system of the file is used. If the bandwidth is
suffixed with K, M, G, or T, the specified bandwidth is parsed as
Kilobytes, Megabytes, Gigabytes, or Terabytes, respectively
(Example: "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M").
This controls the "blkio.read_bps_device" and
"blkio.write_bps_device" control group attributes. Use this option
multiple times to set bandwidth limits for multiple devices. For
details about these control group attributes, see
blkio-controller.txt[4].
Implies "BlockIOAccounting=true".
DeviceAllow=
Control access to specific device nodes by the executed processes.
Takes two space-separated strings: a device node path (such as
/dev/null) followed by a combination of r, w, m to control reading,
writing, or creation of the specific device node by the unit
(mknod), respectively. This controls the "devices.allow" and
"devices.deny" control group attributes. For details about these
control group attributes, see devices.txt[5].
DevicePolicy=auto|closed|strict
Control the policy for allowing device access:
strict
means to only allow types of access that are explicitly
specified.
closed
in addition, allows access to standard pseudo devices including
/dev/null, /dev/zero, /dev/full, /dev/random, and /dev/urandom.
auto
in addition, allows access to all devices if no explicit
DeviceAllow= is present. This is the default.
Slice=
The name of the slice unit to place the unit in. Defaults to
system.slice for all non-instantiated units of all unit types
(except for slice units themselves see below). Instance units are
by default placed in a subslice of system.slice that is named after
the template name.
This option may be used to arrange systemd units in a hierarchy of
slices each of which might have resource settings applied.
For units of type slice, the only accepted value for this setting
is the parent slice. Since the name of a slice unit implies the
parent slice, it is hence redundant to ever set this parameter
directly for slice units.
SEE ALSOsystemd(1), systemd.unit(5), systemd.service(5), systemd.slice(5),
systemd.scope(5), systemd.socket(5), systemd.mount(5), systemd.swap(5),
systemd.directives(7), systemd.special(7), The documentation for
control groups and specific controllers in the Linux kernel:
cgroups.txt[6], cpuacct.txt[7], memory.txt[3], blkio-controller.txt[4].
NOTES
1. New Control Group Interfaces
http://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/
2. sched-design-CFS.txt
https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt
3. memory.txt
https://www.kernel.org/doc/Documentation/cgroups/memory.txt
4. blkio-controller.txt
https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt
5. devices.txt
https://www.kernel.org/doc/Documentation/cgroups/devices.txt
6. cgroups.txt
https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt
7. cpuacct.txt
https://www.kernel.org/doc/Documentation/cgroups/cpuacct.txt
systemd 208SYSTEMD.RESOURCE-CONTROL(5)
