systemd-cgtop — Show top control groups by their resource usage
systemd-cgtop 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 top(1).
If systemd-cgtop is not connected to a
tty, no column headers are printed and the default is to only run
one iteration. The
--iterations= argument, if
given, is honored. This mode is suitable for scripting.
Resource usage is only accounted for control groups in the
relevant hierarchy, i.e. CPU usage is only accounted for control
groups in the "
cpuacct" hierarchy, memory usage
only for those in "
memory" and disk I/O usage for
those in "
blkio". If resource monitoring for
these resources is required, it is recommended to add the
BlockIOAccounting=1 settings in the unit files
in question. See
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 "
To emphasize this: unless
BlockIOAccounting=1" are enabled for the
services in question, no resource accounting will be available for
system services and the data shown by
systemd-cgtop will be incomplete.
The following options are understood:
Order by control group path name.
Order by number of processes in control group.
Order by CPU load.
Order by memory usage.
Order by disk I/O load.
Run in "batch" mode: do not accept input and
run until the iteration limit set with
--iterations= is exhausted or until killed.
This mode could be useful for sending output from
systemd-cgtop to other programs or to a
Format byte counts (as in memory usage and IO metrics) with raw numeric values rather than human-readable numbers.
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 % key.
Include kernel threads when counting tasks in control groups. By default, kernel threads are not included in the count. This setting may also be toggled at runtime by pressing the k key.
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 "
yes". If enabled the
tasks in child control groups are included, if disabled only
the tasks in the control group itself are counted. This
setting may also be toggled at runtime by pressing the
Perform only this many iterations. A value of 0 indicates that the program should run indefinitely.
Specify refresh delay in seconds (or if one of
min" is specified as unit in this time
unit). This setting may also be increased and decreased at
runtime by pressing the + and
Maximum control group tree traversal depth. Specifies how deep systemd-cgtop 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.
systemd-cgtop is an interactive tool and may be controlled via user input using the following keys:
Shows a short help text.
Immediately refresh output.
Terminate the program.
Sort the control groups by path, number of
tasks, CPU load, memory usage, or IO load, respectively. This
setting may also be controlled using the
--order= command line
Toggle between showing CPU time as time or
percentage. This setting may also be controlled using the
--cpu= command line switch.
Increase or decrease refresh delay,
respectively. This setting may also be controlled using the
--delay= command line
Toggle between including or excluding kernel
threads in control group task counts. This setting may also be
controlled using the
-k command line
Toggle between recursively including or
excluding tasks in child control groups in control group task
counts. This setting may also be controlled using the
--recursive= command line
On success, 0 is returned, a non-zero failure code otherwise.