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authorLennart Poettering <lennart@poettering.net>2015-11-10 16:52:52 +0100
committerLennart Poettering <lennart@poettering.net>2015-11-10 17:36:46 +0100
commita4c1800284e3546bbfab2dc19eb59bcb91c4a2ca (patch)
tree4cd44c560d87c8cc1ea86d7c1311feaa885140ff /man/systemd.exec.xml
parentd580265eb4bbbafabdb3b7f0b501c0b05b76b2b7 (diff)
core: accept time units for time-based resource limits
Let's make sure "LimitCPU=30min" can be parsed properly, following the usual logic how we parse time values. Similar for LimitRTTIME=. While we are at it, extend a bit on the man page section about resource limits. Fixes: #1772
Diffstat (limited to 'man/systemd.exec.xml')
-rw-r--r--man/systemd.exec.xml86
1 files changed, 65 insertions, 21 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index 96298f11ed..2b090871ff 100644
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -568,90 +568,133 @@
of various resources for executed processes. See
<citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
for details. Use the string <varname>infinity</varname> to
- configure no limit on a specific resource. The multiplicative suffixes
- K (=1024), M (=1024*1024) and so on for G, T, P and E may be used for
- resource limits measured in bytes (e.g. LimitAS=16G).</para></listitem>
+ configure no limit on a specific resource. The multiplicative
+ suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E
+ may be used for resource limits measured in bytes
+ (e.g. LimitAS=16G). For the limits referring to time values,
+ the usual time units ms, s, min, h and so on may be used (see
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details). Note that if no time unit is specified for
+ <varname>LimitCPU=</varname> the default unit of seconds is
+ implied, while for <varname>LimitRTTIME=</varname> the default
+ unit of microseconds is implied. Also, note that the effective
+ granularity of the limits might influence their
+ enforcement. For example, time limits specified for
+ <varname>LimitCPU=</varname> will be rounded up implicitly to
+ multiples of 1s.</para>
+
+ <para>Note that most process resource limits configured with
+ these options are per-process, and processes may fork in order
+ to acquire a new set of resources that are accounted
+ independently of the original process, and may thus escape
+ limits set. Also note that <varname>LimitRSS=</varname> is not
+ implemented on Linux, and setting it has no effect. Often it
+ is advisable to prefer the resource controls listed in
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ over these per-process limits, as they apply to services as a
+ whole, may be altered dynamically at runtime, and are
+ generally more expressive. For example,
+ <varname>MemoryLimit=</varname> is a more powerful (and
+ working) replacement for <varname>LimitRSS=</varname>.</para>
<table>
<title>Limit directives and their equivalent with ulimit</title>
- <tgroup cols='2'>
+ <tgroup cols='3'>
<colspec colname='directive' />
<colspec colname='equivalent' />
+ <colspec colname='unit' />
<thead>
<row>
<entry>Directive</entry>
<entry>ulimit equivalent</entry>
+ <entry>Unit</entry>
</row>
</thead>
<tbody>
<row>
- <entry>LimitCPU</entry>
+ <entry>LimitCPU=</entry>
<entry>ulimit -t</entry>
+ <entry>Seconds</entry>
</row>
<row>
- <entry>LimitFSIZE</entry>
+ <entry>LimitFSIZE=</entry>
<entry>ulimit -f</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitDATA</entry>
+ <entry>LimitDATA=</entry>
<entry>ulimit -d</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitSTACK</entry>
+ <entry>LimitSTACK=</entry>
<entry>ulimit -s</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitCORE</entry>
+ <entry>LimitCORE=</entry>
<entry>ulimit -c</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitRSS</entry>
+ <entry>LimitRSS=</entry>
<entry>ulimit -m</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitNOFILE</entry>
+ <entry>LimitNOFILE=</entry>
<entry>ulimit -n</entry>
+ <entry>Number of File Descriptors</entry>
</row>
<row>
- <entry>LimitAS</entry>
+ <entry>LimitAS=</entry>
<entry>ulimit -v</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitNPROC</entry>
+ <entry>LimitNPROC=</entry>
<entry>ulimit -u</entry>
+ <entry>Number of Processes</entry>
</row>
<row>
- <entry>LimitMEMLOCK</entry>
+ <entry>LimitMEMLOCK=</entry>
<entry>ulimit -l</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitLOCKS</entry>
+ <entry>LimitLOCKS=</entry>
<entry>ulimit -x</entry>
+ <entry>Number of Locks</entry>
</row>
<row>
- <entry>LimitSIGPENDING</entry>
+ <entry>LimitSIGPENDING=</entry>
<entry>ulimit -i</entry>
+ <entry>Number of Queued Signals</entry>
</row>
<row>
- <entry>LimitMSGQUEUE</entry>
+ <entry>LimitMSGQUEUE=</entry>
<entry>ulimit -q</entry>
+ <entry>Bytes</entry>
</row>
<row>
- <entry>LimitNICE</entry>
+ <entry>LimitNICE=</entry>
<entry>ulimit -e</entry>
+ <entry>Nice Level</entry>
</row>
<row>
- <entry>LimitRTPRIO</entry>
+ <entry>LimitRTPRIO=</entry>
<entry>ulimit -r</entry>
+ <entry>Realtime Priority</entry>
</row>
<row>
- <entry>LimitRTTIME</entry>
+ <entry>LimitRTTIME=</entry>
<entry>No equivalent</entry>
+ <entry>Microseconds</entry>
</row>
</tbody>
</tgroup>
- </table>
+ </table></listitem>
</varlistentry>
<varlistentry>
@@ -1320,6 +1363,7 @@
<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>exec</refentrytitle><manvolnum>3</manvolnum></citerefentry>