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-"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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-
-<refentry id="systemd.resource-control">
- <refentryinfo>
- <title>systemd.resource-control</title>
- <productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
- </refentryinfo>
-
- <refmeta>
- <refentrytitle>systemd.resource-control</refentrytitle>
- <manvolnum>5</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>systemd.resource-control</refname>
- <refpurpose>Resource control unit settings</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <para>
- <filename><replaceable>slice</replaceable>.slice</filename>,
- <filename><replaceable>scope</replaceable>.scope</filename>,
- <filename><replaceable>service</replaceable>.service</filename>,
- <filename><replaceable>socket</replaceable>.socket</filename>,
- <filename><replaceable>mount</replaceable>.mount</filename>,
- <filename><replaceable>swap</replaceable>.swap</filename>
- </para>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para>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.</para>
-
- <para>This man page lists the configuration options shared by
- those six unit types. See
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for the common options of all unit configuration files, and
- <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- and
- <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- 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.</para>
-
- <para>See the <ulink
- url="http://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/">New
- Control Group Interfaces</ulink> for an introduction on how to make
- use of resource control APIs from programs.</para>
- </refsect1>
-
- <refsect1>
- <title>Options</title>
-
- <para>Units of the types listed above can have settings
- for resource control configuration:</para>
-
- <variablelist class='unit-directives'>
-
- <varlistentry>
- <term><varname>CPUAccounting=</varname></term>
-
- <listitem>
- <para>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. The system default for this
- setting maybe controlled with
- <varname>DefaultCPUAccounting=</varname> in
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUShares=<replaceable>weight</replaceable></varname></term>
- <term><varname>StartupCPUShares=<replaceable>weight</replaceable></varname></term>
-
- <listitem>
- <para>Assign the specified CPU time share weight to the
- processes executed. Those options take an integer value and
- control the <literal>cpu.shares</literal> control group
- attribute, which defaults to 1024. For details about this
- control group attribute, see <ulink
- url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.
- The available CPU time is split up among all units within
- one slice relative to their CPU time share weight.</para>
-
- <para>While <varname>StartupCPUShares=</varname> only
- applies to the startup phase of the system,
- <varname>CPUShares=</varname> applies to normal runtime of
- the system, and if the former is not set also to the startup
- phase. Using <varname>StartupCPUShares=</varname> allows
- prioritizing specific services at boot-up differently than
- during normal runtime.</para>
-
- <para>Those options imply
- <literal>CPUAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUQuota=</varname></term>
-
- <listitem>
- <para>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
- <literal>cpu.cfs_quota_us</literal> control group
- attribute. For details about this control group attribute,
- see <ulink
- url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para>
-
- <para>Example: <varname>CPUQuota=20%</varname> ensures that
- the executed processes will never get more than 20% CPU time
- on one CPU.</para>
-
- <para>Implies <literal>CPUAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>MemoryAccounting=</varname></term>
-
- <listitem>
- <para>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 its parent slices. The system default for this setting
- maybe controlled with
- <varname>DefaultMemoryAccounting=</varname> in
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>MemoryLimit=<replaceable>bytes</replaceable></varname></term>
-
- <listitem>
- <para>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
- <literal>memory.limit_in_bytes</literal> control group
- attribute. For details about this control group attribute,
- see <ulink
- url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para>
-
- <para>Implies <literal>MemoryAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIOAccounting=</varname></term>
-
- <listitem>
- <para>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. The system default for this
- setting maybe controlled with
- <varname>DefaultBlockIOAccounting=</varname> in
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIOWeight=<replaceable>weight</replaceable></varname></term>
- <term><varname>StartupBlockIOWeight=<replaceable>weight</replaceable></varname></term>
-
- <listitem><para>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 <literal>blkio.weight</literal> control group attribute,
- which defaults to 1000. For details about this control group
- attribute, see <ulink
- url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.
- The available IO bandwidth is split up among all units within
- one slice relative to their block IO weight.</para>
-
- <para>While <varname>StartupBlockIOWeight=</varname> only
- applies to the startup phase of the system,
- <varname>BlockIOWeight=</varname> 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.</para>
-
- <para>Implies
- <literal>BlockIOAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIODeviceWeight=<replaceable>device</replaceable> <replaceable>weight</replaceable></varname></term>
-
- <listitem>
- <para>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
- <literal>blkio.weight_device</literal> 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 <ulink
- url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para>
-
- <para>Implies
- <literal>BlockIOAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIOReadBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
- <term><varname>BlockIOWriteBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
-
- <listitem>
- <para>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 <literal>blkio.read_bps_device</literal> and
- <literal>blkio.write_bps_device</literal> control group
- attributes. Use this option multiple times to set bandwidth
- limits for multiple devices. For details about these control
- group attributes, see <ulink
- url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.
- </para>
-
- <para>Implies
- <literal>BlockIOAccounting=true</literal>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>DeviceAllow=</varname></term>
-
- <listitem>
- <para>Control access to specific device nodes by the
- executed processes. Takes two space-separated strings: a
- device node specifier followed by a combination of
- <constant>r</constant>, <constant>w</constant>,
- <constant>m</constant> to control
- <emphasis>r</emphasis>eading, <emphasis>w</emphasis>riting,
- or creation of the specific device node(s) by the unit
- (<emphasis>m</emphasis>knod), respectively. This controls
- the <literal>devices.allow</literal> and
- <literal>devices.deny</literal> control group
- attributes. For details about these control group
- attributes, see <ulink
- url="https://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para>
-
- <para>The device node specifier is either a path to a device
- node in the file system, starting with
- <filename>/dev/</filename>, or a string starting with either
- <literal>char-</literal> or <literal>block-</literal>
- followed by a device group name, as listed in
- <filename>/proc/devices</filename>. 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
- <literal>*</literal> and <literal>?</literal>
- wildcards. Examples: <filename>/dev/sda5</filename> is a
- path to a device node, referring to an ATA or SCSI block
- device. <literal>char-pts</literal> and
- <literal>char-alsa</literal> are specifiers for all pseudo
- TTYs and all ALSA sound devices,
- respectively. <literal>char-cpu/*</literal> is a specifier
- matching all CPU related device groups.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>DevicePolicy=auto|closed|strict</varname></term>
-
- <listitem>
- <para>
- Control the policy for allowing device access:
- </para>
- <variablelist>
- <varlistentry>
- <term><option>strict</option></term>
- <listitem>
- <para>means to only allow types of access that are
- explicitly specified.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>closed</option></term>
- <listitem>
- <para>in addition, allows access to standard pseudo
- devices including
- <filename>/dev/null</filename>,
- <filename>/dev/zero</filename>,
- <filename>/dev/full</filename>,
- <filename>/dev/random</filename>, and
- <filename>/dev/urandom</filename>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>auto</option></term>
- <listitem>
- <para>
- in addition, allows access to all devices if no
- explicit <varname>DeviceAllow=</varname> is present.
- This is the default.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Slice=</varname></term>
-
- <listitem>
- <para>The name of the slice unit to place the unit
- in. Defaults to <filename>system.slice</filename> 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 <filename>system.slice</filename>
- that is named after the template name.</para>
-
- <para>This option may be used to arrange systemd units in a
- hierarchy of slices each of which might have resource
- settings applied.</para>
-
- <para>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.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Delegate=</varname></term>
-
- <listitem>
- <para>Turns on delegation of further resource control
- partitioning to processes of the unit. For unprivileged
- services (i.e. those using the <varname>User=</varname>
- 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.</para>
- </listitem>
- </varlistentry>
-
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>See Also</title>
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- The documentation for control groups and specific controllers in the Linux kernel:
- <ulink url="https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>,
- <ulink url="https://www.kernel.org/doc/Documentation/cgroups/cpuacct.txt">cpuacct.txt</ulink>,
- <ulink url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>,
- <ulink url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.
- </para>
- </refsect1>
-</refentry>
~ianmdlvl / elogind.git / blobdiff