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1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?> | |
3 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
4 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> | |
5 | ||
6 | <!-- | |
7 | This file is part of systemd. | |
8 | ||
9 | Copyright 2013 Zbigniew Jędrzejewski-Szmek | |
10 | ||
11 | systemd is free software; you can redistribute it and/or modify it | |
12 | under the terms of the GNU Lesser General Public License as published by | |
13 | the Free Software Foundation; either version 2.1 of the License, or | |
14 | (at your option) any later version. | |
15 | ||
16 | systemd is distributed in the hope that it will be useful, but | |
17 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | Lesser General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU Lesser General Public License | |
22 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
23 | --> | |
24 | ||
25 | <refentry id="systemd.cgroup"> | |
26 | <refentryinfo> | |
27 | <title>systemd.cgroup</title> | |
28 | <productname>systemd</productname> | |
29 | ||
30 | <authorgroup> | |
31 | <author> | |
32 | <contrib>Developer</contrib> | |
33 | <firstname>Lennart</firstname> | |
34 | <surname>Poettering</surname> | |
35 | <email>lennart@poettering.net</email> | |
36 | </author> | |
37 | </authorgroup> | |
38 | </refentryinfo> | |
39 | ||
40 | <refmeta> | |
41 | <refentrytitle>systemd.cgroup</refentrytitle> | |
42 | <manvolnum>5</manvolnum> | |
43 | </refmeta> | |
44 | ||
45 | <refnamediv> | |
46 | <refname>systemd.cgroup</refname> | |
9365b048 | 47 | <refpurpose>Control Group configuration unit settings</refpurpose> |
d868475a ZJS |
48 | </refnamediv> |
49 | ||
50 | <refsynopsisdiv> | |
51 | <para> | |
52 | <filename><replaceable>slice</replaceable>.slice</filename>, | |
53 | <filename><replaceable>scope</replaceable>.scope</filename>, | |
54 | <filename><replaceable>service</replaceable>.service</filename>, | |
55 | <filename><replaceable>socket</replaceable>.socket</filename>, | |
56 | <filename><replaceable>mount</replaceable>.mount</filename>, | |
57 | <filename><replaceable>swap</replaceable>.swap</filename> | |
58 | </para> | |
59 | </refsynopsisdiv> | |
60 | ||
61 | <refsect1> | |
62 | <title>Description</title> | |
63 | ||
64 | <para>Unit configuration files for services, slices, scopes, | |
65 | sockets, mount points, and swap devices share a subset of | |
66 | configuration options which configure the control group settings | |
67 | for spawned processes.</para> | |
68 | ||
9365b048 LP |
69 | <para>Control Groups is a concept for organizing processes in a |
70 | hierarch tree of named groups for the purpose of resource | |
71 | management.</para> | |
72 | ||
d868475a ZJS |
73 | <para>This man page lists the configuration options shared by |
74 | those six unit types. See | |
75 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
76 | for the common options of all unit configuration files, and | |
77 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
78 | <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
79 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
80 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
81 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
82 | and | |
83 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
84 | for more information on the specific unit configuration files. The | |
6a75304e | 85 | execution-specific configuration options are configured in the |
d868475a ZJS |
86 | [Slice], [Scope], [Service], [Socket], [Mount], or [Swap] |
87 | sections, depending on the unit type.</para> | |
88 | </refsect1> | |
89 | ||
90 | <refsect1> | |
91 | <title>Options</title> | |
92 | ||
93 | <para>Units of the types listed above can have settings | |
94 | for cgroup configuration:</para> | |
95 | ||
96 | <variablelist class='unit-directives'> | |
d868475a ZJS |
97 | |
98 | <varlistentry> | |
61ad59b1 | 99 | <term><varname>CPUAccounting=</varname></term> |
d868475a ZJS |
100 | |
101 | <listitem> | |
61ad59b1 LP |
102 | <para>Turn on CPU usage accounting for this unit. Takes a |
103 | boolean argument. Note that turning on CPU accounting for | |
104 | one unit might also implicitly turn it on for all units | |
105 | contained in the same slice and for all its parent slices and | |
106 | the units contained therein.</para> | |
d868475a ZJS |
107 | </listitem> |
108 | </varlistentry> | |
109 | ||
d868475a ZJS |
110 | <varlistentry> |
111 | <term><varname>CPUShares=<replaceable>weight</replaceable></varname></term> | |
112 | ||
113 | <listitem> | |
114 | <para>Assign the specified overall CPU time share weight to | |
115 | the processes executed. Takes an integer value. This | |
116 | controls the <literal>cpu.shares</literal> control group | |
117 | attribute, which defaults to 1024. For details about this | |
6a75304e | 118 | control group attribute, see <ulink |
6ed80a4e | 119 | url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para> |
d868475a ZJS |
120 | |
121 | <para>Implies <literal>CPUAccounting=true</literal>.</para> | |
122 | </listitem> | |
123 | </varlistentry> | |
124 | ||
61ad59b1 LP |
125 | <varlistentry> |
126 | <term><varname>MemoryAccounting=</varname></term> | |
127 | ||
128 | <listitem> | |
129 | <para>Turn on process and kernel memory accounting for this | |
130 | unit. Takes a boolean argument. Note that turning on memory | |
131 | accounting for one unit might also implicitly turn it on for | |
132 | all units contained in the same slice and for all its parent | |
133 | slices and the units contained therein.</para> | |
134 | </listitem> | |
135 | </varlistentry> | |
136 | ||
d868475a ZJS |
137 | <varlistentry> |
138 | <term><varname>MemoryLimit=<replaceable>bytes</replaceable></varname></term> | |
139 | <term><varname>MemorySoftLimit=<replaceable>bytes</replaceable></varname></term> | |
140 | ||
141 | <listitem> | |
142 | <para>Specify the hard and soft limits on maximum memory | |
143 | usage of the executed processes. The "hard" limit specifies | |
144 | how much process and kernel memory can be used by tasks in | |
145 | this unit, when there is no memory contention. If the kernel | |
146 | detects memory contention, memory reclaim will be performed | |
147 | until the memory usage is within the "soft" limit. Takes a | |
148 | memory size in bytes. If the value is suffixed with K, M, G | |
6a75304e | 149 | or T, the specified memory size is parsed as Kilobytes, |
d868475a ZJS |
150 | Megabytes, Gigabytes, or Terabytes (with the base 1024), |
151 | respectively. This controls the | |
152 | <literal>memory.limit_in_bytes</literal> and | |
153 | <literal>memory.soft_limit_in_bytes</literal> control group | |
6a75304e | 154 | attributes. For details about these control group attributes, |
d868475a | 155 | see <ulink |
6ed80a4e | 156 | url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para> |
d868475a ZJS |
157 | |
158 | <para>Implies <literal>MemoryAccounting=true</literal>.</para> | |
159 | </listitem> | |
160 | </varlistentry> | |
161 | ||
61ad59b1 LP |
162 | <varlistentry> |
163 | <term><varname>BlockIOAccounting=</varname></term> | |
164 | ||
165 | <listitem> | |
166 | <para>Turn on Block IO accounting for this unit. Takes a | |
167 | boolean argument. Note that turning on block IO accounting | |
168 | for one unit might also implicitly turn it on for all units | |
169 | contained in the same slice and all for its parent slices and | |
170 | the units contained therein.</para> | |
171 | </listitem> | |
172 | </varlistentry> | |
173 | ||
d868475a ZJS |
174 | <varlistentry> |
175 | <term><varname>BlockIOWeight=<replaceable>weight</replaceable></varname></term> | |
176 | ||
177 | <listitem><para>Set the default | |
178 | overall block IO weight for the | |
179 | executed processes. Takes a single | |
180 | weight value (between 10 and 1000) to | |
181 | set the default block IO weight. This | |
182 | controls the | |
183 | <literal>blkio.weight</literal> | |
184 | control group attribute, which | |
185 | defaults to 1000. For details about | |
6a75304e | 186 | this control group attribute, see |
d868475a | 187 | <ulink |
61ad59b1 LP |
188 | url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para> |
189 | ||
190 | <para>Implies | |
191 | <literal>BlockIOAccounting=true</literal>.</para> | |
192 | </listitem> | |
d868475a ZJS |
193 | </varlistentry> |
194 | ||
195 | <varlistentry> | |
196 | <term><varname>BlockIODeviceWeight=<replaceable>device</replaceable> <replaceable>weight</replaceable></varname></term> | |
197 | ||
198 | <listitem> | |
199 | <para>Set the per-device overall block IO weight for the | |
200 | executed processes. Takes a space-separated pair of a file | |
201 | path and a weight value to specify the device specific | |
202 | weight value, between 10 and 1000. (Example: "/dev/sda | |
203 | 500"). The file path may be specified as path to a block | |
204 | device node or as any other file in which case the backing | |
205 | block device of the file system of the file is | |
206 | determined. This controls the | |
207 | <literal>blkio.weight_device</literal> control group | |
208 | attribute, which defaults to 1000. Use this option multiple | |
209 | times to set weights for multiple devices. For details about | |
6a75304e | 210 | this control group attribute, see <ulink |
6ed80a4e | 211 | url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para> |
61ad59b1 LP |
212 | |
213 | <para>Implies | |
214 | <literal>BlockIOAccounting=true</literal>.</para> | |
d868475a ZJS |
215 | </listitem> |
216 | </varlistentry> | |
217 | ||
218 | <varlistentry> | |
219 | <term><varname>BlockIOReadBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term> | |
220 | <term><varname>BlockIOWriteBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term> | |
221 | ||
222 | <listitem> | |
223 | <para>Set the per-device overall block IO bandwidth limit | |
224 | for the executed processes. Takes a space-separated pair of | |
225 | a file path and a bandwidth value (in bytes per second) to | |
226 | specify the device specific bandwidth. The file path may be | |
227 | a path to a block device node, or as any other file in which | |
228 | case the backing block device of the file system of the file | |
6a75304e | 229 | is used. If the bandwidth is suffixed with K, M, G, or T, |
d868475a ZJS |
230 | the specified bandwidth is parsed as Kilobytes, Megabytes, |
231 | Gigabytes, or Terabytes, respectively (Example: | |
232 | "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This | |
233 | controls the <literal>blkio.read_bps_device</literal> and | |
234 | <literal>blkio.write_bps_device</literal> control group | |
235 | attributes. Use this option multiple times to set bandwidth | |
236 | limits for multiple devices. For details about these control | |
6a75304e | 237 | group attributes, see |
6ed80a4e | 238 | <ulink url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>. |
d868475a | 239 | </para> |
61ad59b1 LP |
240 | |
241 | <para>Implies | |
242 | <literal>BlockIOAccounting=true</literal>.</para> | |
d868475a ZJS |
243 | </listitem> |
244 | </varlistentry> | |
245 | ||
246 | <varlistentry> | |
247 | <term><varname>DeviceAllow=</varname></term> | |
248 | ||
249 | <listitem> | |
250 | <para>Control access to specific device nodes by the | |
251 | executed processes. Takes two space-separated strings: a | |
252 | device node path (such as <filename>/dev/null</filename>) | |
253 | followed by a combination of <constant>r</constant>, | |
254 | <constant>w</constant>, <constant>m</constant> to control | |
255 | <emphasis>r</emphasis>eading, <emphasis>w</emphasis>riting, | |
6a75304e | 256 | or creation of the specific device node by the unit |
d868475a ZJS |
257 | (<emphasis>m</emphasis>knod), respectively. This controls |
258 | the <literal>devices.allow</literal> and | |
259 | <literal>devices.deny</literal> control group | |
6a75304e | 260 | attributes. For details about these control group attributes, |
d868475a | 261 | see <ulink |
6ed80a4e | 262 | url="https://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para> |
d868475a ZJS |
263 | </listitem> |
264 | </varlistentry> | |
265 | ||
266 | <varlistentry> | |
267 | <term><varname>DevicePolicy=auto|closed|strict</varname></term> | |
268 | ||
269 | <listitem> | |
270 | <para> | |
271 | Control the policy for allowing device access: | |
272 | </para> | |
273 | <variablelist> | |
274 | <varlistentry> | |
275 | <term><option>strict</option></term> | |
276 | <listitem> | |
277 | <para>means to only allow types of access that are | |
278 | explicitly specified.</para> | |
279 | </listitem> | |
280 | </varlistentry> | |
281 | ||
282 | <varlistentry> | |
283 | <term><option>closed</option></term> | |
284 | <listitem> | |
6a75304e | 285 | <para>in addition, allows access to standard pseudo |
d868475a ZJS |
286 | devices including |
287 | <filename>/dev/null</filename>, | |
288 | <filename>/dev/zero</filename>, | |
289 | <filename>/dev/full</filename>, | |
290 | <filename>/dev/random</filename>, and | |
291 | <filename>/dev/urandom</filename>. | |
292 | </para> | |
293 | </listitem> | |
294 | </varlistentry> | |
295 | ||
296 | <varlistentry> | |
297 | <term><option>auto</option></term> | |
298 | <listitem> | |
299 | <para> | |
6a75304e | 300 | in addition, allows access to all devices if no |
d868475a ZJS |
301 | explicit <varname>DeviceAllow=</varname> is present. |
302 | This is the default. | |
303 | </para> | |
304 | </listitem> | |
305 | </varlistentry> | |
306 | </variablelist> | |
307 | </listitem> | |
308 | </varlistentry> | |
61ad59b1 LP |
309 | |
310 | <varlistentry> | |
311 | <term><varname>Slice=</varname></term> | |
312 | ||
313 | <listitem> | |
314 | <para>The name of the slice unit to place the unit | |
315 | in. Defaults to <filename>system.slice</filename> for all | |
dc7adf20 LP |
316 | non-instantiated units of all unit types (except for slice |
317 | units themselves see below). Instance units are by default | |
318 | placed in a subslice of <filename>system.slice</filename> | |
319 | that is named after the template name.</para> | |
320 | ||
321 | <para>This option may be used to arrange systemd units in a | |
322 | hierarchy of slices each of which might have resource | |
323 | settings applied.</para> | |
61ad59b1 | 324 | |
fbce1139 | 325 | <para>For units of type slice, the only accepted value for |
61ad59b1 | 326 | this setting is the parent slice. Since the name of a slice |
fbce1139 | 327 | unit implies the parent slice, it is hence redundant to ever |
61ad59b1 LP |
328 | set this parameter directly for slice units.</para> |
329 | </listitem> | |
330 | </varlistentry> | |
331 | ||
d868475a ZJS |
332 | </variablelist> |
333 | </refsect1> | |
334 | ||
335 | <refsect1> | |
336 | <title>See Also</title> | |
337 | <para> | |
338 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
339 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
340 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
341 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
342 | <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
343 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
344 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
345 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
346 | <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
61ad59b1 | 347 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
d868475a | 348 | The documentation for control groups and specific controllers in the Linux kernel: |
6ed80a4e JSJ |
349 | <ulink url="https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>, |
350 | <ulink url="https://www.kernel.org/doc/Documentation/cgroups/cpuacct.txt">cpuacct.txt</ulink>, | |
351 | <ulink url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>, | |
352 | <ulink url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>. | |
d868475a ZJS |
353 | </para> |
354 | </refsect1> | |
355 | </refentry> |