systemd/man/systemd-cgtop.xml
Alessandro Puccetti 308253c5a2 cgtop: add option to show a single cgroup subtree (#3413)
When many services are running, it was difficult to see only the interesting ones.
This patch allows to show only the subtree of interest.
2016-06-05 13:42:37 -04:00

378 lines
14 KiB
XML

<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<refentry id="systemd-cgtop"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>systemd-cgtop</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-cgtop</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-cgtop</refname>
<refpurpose>Show top control groups by their resource usage</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemd-cgtop</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="opt">GROUP</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>systemd-cgtop</command> shows the top control
groups of the local Linux control group hierarchy, ordered by
their CPU, memory, or disk I/O load. The display is refreshed in
regular intervals (by default every 1s), similar in style to
<citerefentry project='man-pages'><refentrytitle>top</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
If a control group path is specified, shows only the services of
the specified control group.</para>
<para>If <command>systemd-cgtop</command> is not connected to a
tty, no column headers are printed and the default is to only run
one iteration. The <varname>--iterations=</varname> argument, if
given, is honored. This mode is suitable for scripting.</para>
<para>Resource usage is only accounted for control groups in the
relevant hierarchy, i.e. CPU usage is only accounted for control
groups in the <literal>cpuacct</literal> hierarchy, memory usage
only for those in <literal>memory</literal> and disk I/O usage for
those in <literal>blkio</literal>. If resource monitoring for
these resources is required, it is recommended to add the
<varname>CPUAccounting=1</varname>,
<varname>MemoryAccounting=1</varname> and
<varname>BlockIOAccounting=1</varname> settings in the unit files
in question. See
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details.</para>
<para>The CPU load value can be between 0 and 100 times the number of
processors the system has. For example, if the system has 8 processors,
the CPU load value is going to be between 0% and 800%. The number of
processors can be found in <literal>/proc/cpuinfo</literal>.</para>
<para>To emphasize this: unless
<literal>CPUAccounting=1</literal>,
<literal>MemoryAccounting=1</literal> and
<literal>BlockIOAccounting=1</literal> are enabled for the
services in question, no resource accounting will be available for
system services and the data shown by
<command>systemd-cgtop</command> will be incomplete.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>-p</option></term>
<term><option>--order=path</option></term>
<listitem><para>Order by control group
path name.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-t</option></term>
<term><option>--order=tasks</option></term>
<listitem><para>Order by number of tasks/processes in the control group.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-c</option></term>
<term><option>--order=cpu</option></term>
<listitem><para>Order by CPU load.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-m</option></term>
<term><option>--order=memory</option></term>
<listitem><para>Order by memory usage.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-i</option></term>
<term><option>--order=io</option></term>
<listitem><para>Order by disk I/O load.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-b</option></term>
<term><option>--batch</option></term>
<listitem><para>Run in "batch" mode: do not accept input and
run until the iteration limit set with
<option>--iterations=</option> is exhausted or until killed.
This mode could be useful for sending output from
<command>systemd-cgtop</command> to other programs or to a
file.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-r</option></term>
<term><option>--raw</option></term>
<listitem><para>Format byte counts (as in memory usage and I/O metrics)
with raw numeric values rather than human-readable
numbers.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--cpu=percentage</option></term>
<term><option>--cpu=time</option></term>
<listitem><para>Controls whether the CPU usage is shown as
percentage or time. By default, the CPU usage is shown as
percentage. This setting may also be toggled at runtime by
pressing the <keycap>%</keycap> key.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-P</option></term>
<listitem><para>Count only userspace processes instead of all
tasks. By default, all tasks are counted: each kernel thread
and each userspace thread individually. With this setting,
kernel threads are excluded from the counting and each
userspace process only counts as one, regardless how many
threads it consists of. This setting may also be toggled at
runtime by pressing the <keycap>P</keycap> key. This option
may not be combined with
<option>-k</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-k</option></term>
<listitem><para>Count only userspace processes and kernel
threads instead of all tasks. By default, all tasks are
counted: each kernel thread and each userspace thread
individually. With this setting, kernel threads are included in
the counting and each userspace process only counts as on one,
regardless how many threads it consists of. This setting may
also be toggled at runtime by pressing the <keycap>k</keycap>
key. This option may not be combined with
<option>-P</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--recursive=</option></term>
<listitem><para>Controls whether the number of processes shown
for a control group shall include all processes that are
contained in any of the child control groups as well. Takes a
boolean argument, which defaults to <literal>yes</literal>. If
enabled, the processes in child control groups are included, if
disabled, only the processes in the control group itself are
counted. This setting may also be toggled at runtime by
pressing the <keycap>r</keycap> key. Note that this setting
only applies to process counting, i.e. when the
<option>-P</option> or <option>-k</option> options are
used. It has not effect if all tasks are counted, in which
case the counting is always recursive.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-n</option></term>
<term><option>--iterations=</option></term>
<listitem><para>Perform only this many iterations. A value of
0 indicates that the program should run
indefinitely.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-d</option></term>
<term><option>--delay=</option></term>
<listitem><para>Specify refresh delay in seconds (or if one of
<literal>ms</literal>, <literal>us</literal>,
<literal>min</literal> is specified as unit in this time
unit). This setting may also be increased and decreased at
runtime by pressing the <keycap>+</keycap> and
<keycap>-</keycap> keys.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--depth=</option></term>
<listitem><para>Maximum control group tree traversal depth.
Specifies how deep <command>systemd-cgtop</command> shall
traverse the control group hierarchies. If 0 is specified,
only the root group is monitored. For 1, only the first level
of control groups is monitored, and so on. Defaults to
3.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-M <replaceable>MACHINE</replaceable></option></term>
<term><option>--machine=<replaceable>MACHINE</replaceable></option></term>
<listitem><para>Limit control groups shown to the part
corresponding to the container
<replaceable>MACHINE</replaceable>.
This option may not be used when a control group path is specified.</para></listitem>
</varlistentry>
<xi:include href="standard-options.xml" xpointer="help" />
<xi:include href="standard-options.xml" xpointer="version" />
</variablelist>
</refsect1>
<refsect1>
<title>Keys</title>
<para><command>systemd-cgtop</command> is an interactive tool and
may be controlled via user input using the following keys:</para>
<variablelist>
<varlistentry>
<term><keycap>h</keycap></term>
<listitem><para>Shows a short help text.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap function="space"/></term>
<listitem><para>Immediately refresh output.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>q</keycap></term>
<listitem><para>Terminate the program.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>p</keycap></term>
<term><keycap>t</keycap></term>
<term><keycap>c</keycap></term>
<term><keycap>m</keycap></term>
<term><keycap>i</keycap></term>
<listitem><para>Sort the control groups by path, number of
tasks, CPU load, memory usage, or I/O load, respectively. This
setting may also be controlled using the
<option>--order=</option> command line
switch.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>%</keycap></term>
<listitem><para>Toggle between showing CPU time as time or
percentage. This setting may also be controlled using the
<option>--cpu=</option> command line switch.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>+</keycap></term>
<term><keycap>-</keycap></term>
<listitem><para>Increase or decrease refresh delay,
respectively. This setting may also be controlled using the
<option>--delay=</option> command line
switch.</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>P</keycap></term>
<listitem><para>Toggle between counting all tasks, or only
userspace processes. This setting may also be controlled using
the <option>-P</option> command line switch (see
above).</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>k</keycap></term>
<listitem><para>Toggle between counting all tasks, or only
userspace processes and kernel threads. This setting may also
be controlled using the <option>-k</option> command line
switch (see above).</para></listitem>
</varlistentry>
<varlistentry>
<term><keycap>r</keycap></term>
<listitem><para>Toggle between recursively including or
excluding processes in child control groups in control group
process counts. This setting may also be controlled using the
<option>--recursive=</option> command line switch. This key is
not available if all tasks are counted, it is only available
if processes are counted, as enabled with the
<keycap>P</keycap> or <keycap>k</keycap>
keys.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success, 0 is returned, a non-zero failure code
otherwise.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-cgls</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>top</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>