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SYSTEMD.RESOURCE-CONTROL(5)systemd.resource-controlSYSTEMD.RESOURCE-CONTROL(5)

NAME
       systemd.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
       Control Groups kernel concept for organizing processes in a
       hierarchical 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 on 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 will
           also implicitly turn it on for all units contained in the same
           slice and for all its parent slices and the units contained
           therein. The system default for this setting may be controlled with
           DefaultCPUAccounting= in systemd-system.conf(5).
       CPUShares=weight, StartupCPUShares=weight
           Assign the specified CPU time share weight to the processes
           executed. These options take an integer value and control the
           "cpu.shares" control group attribute. The allowed range is 2 to
           262144. Defaults to 1024. For details about this control group
           attribute, see sched-design-CFS.txt[2]. The available CPU time is
           split up among all units within one slice relative to their CPU
           time share weight.
           While StartupCPUShares= only applies to the startup phase of the
           system, CPUShares= applies to normal runtime of the system, and if
           the former is not set also to the startup phase. Using
           StartupCPUShares= allows prioritizing specific services at boot-up
           differently than during normal runtime.
           These options imply "CPUAccounting=true".
       CPUQuota=
           Assign the specified CPU time quota to the processes executed.
           Takes a percentage value, suffixed with "%". The percentage
           specifies how much CPU time the unit shall get at maximum, relative
           to the total CPU time available on one CPU. Use values > 100% for
           allotting CPU time on more than one CPU. This controls the
           "cpu.cfs_quota_us" control group attribute. For details about this
           control group attribute, see sched-design-CFS.txt[2].
           Example: CPUQuota=20% ensures that the executed processes will
           never get more than 20% CPU time on one CPU.
           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 will also implicitly turn it on for all units contained in the
           same slice and for all its parent slices and the units contained
           therein. The system default for this setting may be controlled with
           DefaultMemoryAccounting= in systemd-system.conf(5).
       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. If assigned the special value
           "infinity" no memory limit is applied. This controls the
           "memory.limit_in_bytes" control group attribute. For details about
           this control group attribute, see memory.txt[3].
           Implies "MemoryAccounting=true".
       TasksAccounting=
           Turn on task accounting for this unit. Takes a boolean argument. If
           enabled, the system manager will keep track of the number of tasks
           in the unit. The number of tasks accounted this way includes both
           kernel threads and userspace processes, with each thread counting
           individually. Note that turning on tasks accounting for one unit
           will also implicitly turn it on for all units contained in the same
           slice and for all its parent slices and the units contained
           therein. The system default for this setting may be controlled with
           DefaultTasksAccounting= in systemd-system.conf(5).
       TasksMax=N
           Specify the maximum number of tasks that may be created in the
           unit. This ensures that the number of tasks accounted for the unit
           (see above) stays below a specific limit. This either takes an
           absolute number of tasks or a percentage value that is taken
           relative to the configured maximum number of tasks on the system.
           If assigned the special value "infinity", no tasks limit is
           applied. This controls the "pids.max" control group attribute. For
           details about this control group attribute, see pids.txt[4].
           Implies "TasksAccounting=true". The system default for this setting
           may be controlled with DefaultTasksMax= in systemd-system.conf(5).
       BlockIOAccounting=
           Turn on Block IO accounting for this unit. Takes a boolean
           argument. Note that turning on block IO accounting for one unit
           will also implicitly turn it on for all units contained in the same
           slice and all for its parent slices and the units contained
           therein. The system default for this setting may be controlled with
           DefaultBlockIOAccounting= in systemd-system.conf(5).
       BlockIOWeight=weight, StartupBlockIOWeight=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 500. For details about this
           control group attribute, see blkio-controller.txt[5]. The available
           IO bandwidth is split up among all units within one slice relative
           to their block IO weight.
           While StartupBlockIOWeight= only applies to the startup phase of
           the system, BlockIOWeight= applies to the later runtime of the
           system, and if the former is not set also to the startup phase.
           This allows prioritizing specific services at boot-up differently
           than during runtime.
           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[5].
           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, to the
           base of 1000. (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[5].
           Implies "BlockIOAccounting=true".
       DeviceAllow=
           Control access to specific device nodes by the executed processes.
           Takes two space-separated strings: a device node specifier followed
           by a combination of r, w, m to control reading, writing, or
           creation of the specific device node(s) 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[6].
           The device node specifier is either a path to a device node in the
           file system, starting with /dev/, or a string starting with either
           "char-" or "block-" followed by a device group name, as listed in
           /proc/devices. The latter is useful to whitelist all current and
           future devices belonging to a specific device group at once. The
           device group is matched according to file name globbing rules, you
           may hence use the "*" and "?"  wildcards. Examples: /dev/sda5 is a
           path to a device node, referring to an ATA or SCSI block device.
           "char-pts" and "char-alsa" are specifiers for all pseudo TTYs and
           all ALSA sound devices, respectively.  "char-cpu/*" is a specifier
           matching all CPU related device groups.
       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.
       Delegate=
           Turns on delegation of further resource control partitioning to
           processes of the unit. For unprivileged services (i.e. those using
           the User= setting) this allows processes to create a subhierarchy
           beneath its control group path. For privileged services and scopes
           this ensures the processes will have all control group controllers
           enabled.
SEE ALSO
       systemd(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[7], cpuacct.txt[8], memory.txt[3], blkio-controller.txt[5].
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. pids.txt
           https://www.kernel.org/doc/Documentation/cgroup-v1/pids.txt
        5. blkio-controller.txt
           https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt
        6. devices.txt
           https://www.kernel.org/doc/Documentation/cgroups/devices.txt
        7. cgroups.txt
           https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt
        8. cpuacct.txt
           https://www.kernel.org/doc/Documentation/cgroups/cpuacct.txt

systemd 219                                        SYSTEMD.RESOURCE-CONTROL(5)