systemd-cgtop Man page

SYSTEMD-CGTOP(1) systemd-cgtop SYSTEMD-CGTOP(1)

NAME

systemd-cgtop – Show top control groups by their resource usage

SYNOPSIS

systemd-cgtop [OPTIONS…]

DESCRIPTION

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.

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 CPUAccounting=1,
MemoryAccounting=1 and BlockIOAccounting=1 settings in the unit files
in question. See systemd.resource-control(5) for details.

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 “/proc/cpuinfo”.

To emphasize this: unless “CPUAccounting=1”, “MemoryAccounting=1” and
“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.

OPTIONS

The following options are understood:

-p, –order=path
Order by control group path name.

-t, –order=tasks
Order by number of tasks/processes in the control group.

-c, –order=cpu
Order by CPU load.

-m, –order=memory
Order by memory usage.

-i, –order=io
Order by disk I/O load.

-b, –batch
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 file.

-r, –raw
Format byte counts (as in memory usage and I/O metrics) with raw
numeric values rather than human-readable numbers.

–cpu=percentage, –cpu=time
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.

-P
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 P key. This option may not be
combined with -k.

-k
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 k key.
This option may not be combined with -P.

–recursive=
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
“yes”. 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 r key. Note that this setting only applies to process
counting, i.e. when the -P or -k options are used. It has not
effect if all tasks are counted, in which case the counting is
always recursive.

-n, –iterations=
Perform only this many iterations. A value of 0 indicates that the
program should run indefinitely.

-d, –delay=
Specify refresh delay in seconds (or if one of “ms”, “us”, “min” is
specified as unit in this time unit). This setting may also be
increased and decreased at runtime by pressing the + and – keys.

–depth=
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.

-M MACHINE, –machine=MACHINE
Limit control groups shown to the part corresponding to the
container MACHINE.

-h, –help
Print a short help text and exit.

–version
Print a short version string and exit.

KEYS
systemd-cgtop is an interactive tool and may be controlled via user
input using the following keys:

h
Shows a short help text.

Space
Immediately refresh output.

q
Terminate the program.

p, t, c, m, i
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 –order= command line switch.

%
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 switch.

P
Toggle between counting all tasks, or only userspace processes.
This setting may also be controlled using the -P command line
switch (see above).

k
Toggle between counting all tasks, or only userspace processes and
kernel threads. This setting may also be controlled using the -k
command line switch (see above).

r
Toggle between recursively including or excluding processes in
child control groups in control group process counts. This setting
may also be controlled using the –recursive= 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 P or k
keys.

EXIT STATUS
On success, 0 is returned, a non-zero failure code otherwise.

SEE ALSO

systemd, systemctl, systemd-cgls, systemd.resource-control(5),
top

systemd 229 SYSTEMD-CGTOP(1)