cgtop: recursively count cgroup member tasks

[thirdparty/systemd.git] / man / systemd-cgtop.xml

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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>
    </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>.</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 processes in 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 IO 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.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-k</option></term>

        <listitem><para>Include kernel threads when counting tasks in
        control groups. By default, kernel threads are not included in
        the count.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--recursive=</option></term>

        <listitem><para>Controls whether the number of tasks shown for
        a control group shall include all tasks that are contained in
        any of the child control groups as well. Takes a boolean
        argument, defaults to <literal>yes</literal>. If enabled the
        tasks in child control groups are included, if disabled only
        the tasks in the control group itself are
        counted.</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).</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>

      <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>h</term>

        <listitem><para>Shows a short help text.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>SPACE</term>

        <listitem><para>Immediately refresh output.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>q</term>

        <listitem><para>Terminate the program.</para></listitem>
      </varlistentry>


      <varlistentry>
        <term>p</term>
        <term>t</term>
        <term>c</term>
        <term>m</term>
        <term>i</term>

        <listitem><para>Sort the control groups by path, number of
        tasks, CPU load, memory usage, or IO load, respectively.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term>%</term>

        <listitem><para>Toggle between showing CPU time as time or
        percentage.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>+</term>
        <term>-</term>

        <listitem><para>Increase or decrease refresh delay,
        respectively.</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>