Manual: pidstat
PIDSTAT(1) Linux User's Manual PIDSTAT(1)
NAME
pidstat - Report statistics for Linux tasks.
SYNOPSIS
pidstat [ -d ] [ -H ] [ -h ] [ -I ] [ -l ] [ -R ] [ -r ] [ -s ] [ -t ] [ -U [ username ] ] [ -u ] [ -V ] [ -v ] [ -w
] [ -C comm ] [ -G process_name ] [ --dec={ 0 | 1 | 2 } ] [ --human ] [ -o JSON ] [ -p { pid[,...] | SELF | ALL } ]
[ -T { TASK | CHILD | ALL } ] [ interval [ count ] ] [ -e program args ]
DESCRIPTION
The pidstat command is used for monitoring individual tasks currently being managed by the Linux kernel. It writes
to standard output activities for every task selected with option -p or for every task managed by the Linux kernel if
option -p ALL has been used. Not selecting any tasks is equivalent to specifying -p ALL but only active tasks (tasks
with non-zero statistics values) will appear in the report.
The pidstat command can also be used for monitoring the child processes of selected tasks. Read about option -T be‐
low.
The interval parameter specifies the amount of time in seconds between each report. A value of 0 (or no parameters
at all) indicates that tasks statistics are to be reported for the time since system startup (boot). The count para‐
meter can be specified in conjunction with the interval parameter if this one is not set to zero. The value of count
determines the number of reports generated at interval seconds apart. If the interval parameter is specified without
the count parameter, the pidstat command generates reports continuously.
You can select information about specific task activities using flags. Not specifying any flags selects only CPU ac‐
tivity.
OPTIONS
-C comm
Display only tasks whose command name includes the string comm. This string can be a regular expression.
-d Report I/O statistics (kernels 2.6.20 and later only). The following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
kB_rd/s
Number of kibibytes the task has caused to be read from disk per second.
kB_wr/s
Number of kibibytes the task has caused, or shall cause to be written to disk per second.
kB_ccwr/s
Number of kibibytes whose writing to disk has been cancelled by the task. This may occur when the task
truncates some dirty pagecache. In this case, some IO which another task has been accounted for will
not be happening.
iodelay
Block I/O delay of the task being monitored, measured in clock ticks. This metric includes the delays
spent waiting for sync block I/O completion and for swapin block I/O completion.
Command
The command name of the task.
--dec={ 0 | 1 | 2 }
Specify the number of decimal places to use (0 to 2, default value is 2).
-e program args
Execute program with given arguments args and monitor it with pidstat. pidstat stops when program terminates.
A non-zero value must be specified for the interval parameter.
-G process_name
Display only processes whose command name includes the string process_name. This string can be a regular ex‐
pression. If option -t is used together with option -G then the threads belonging to that process are also
displayed (even if their command name doesn't include the string process_name).
-H Display timestamp in seconds since the epoch.
-h Display all activities horizontally on a single line, with no average statistics at the end of the report.
This is intended to make it easier to be parsed by other programs.
--human
Print sizes in human readable format (e.g. 1.0k, 1.2M, etc.) The units displayed with this option supersede
any other default units (e.g. kibibytes, sectors...) associated with the metrics.
-I In an SMP environment, indicate that tasks CPU usage (as displayed by option -u) should be divided by the to‐
tal number of processors.
-l Display the process command name and all its arguments.
-o JSON
Display the statistics in JSON (JavaScript Object Notation) format. JSON output field order is undefined, and
new fields may be added in the future.
-p { pid[,...] | SELF | ALL }
Select tasks (processes) for which statistics are to be reported. pid is the process identification number.
The SELF keyword indicates that statistics are to be reported for the pidstat process itself, whereas the ALL
keyword indicates that statistics are to be reported for all the tasks managed by the system.
-R Report realtime priority and scheduling policy information. The following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
prio The realtime priority of the task being monitored.
policy The scheduling policy of the task being monitored.
Command
The command name of the task.
-r Report page faults and memory utilization.
When reporting statistics for individual tasks, the following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
minflt/s
Total number of minor faults the task has made per second, those which have not required loading a mem‐
ory page from disk.
majflt/s
Total number of major faults the task has made per second, those which have required loading a memory
page from disk.
VSZ Virtual Size: The virtual memory usage of entire task in kibibytes.
RSS Resident Set Size: The non-swapped physical memory used by the task in kibibytes.
%MEM The tasks's currently used share of available physical memory.
Command
The command name of the task.
When reporting global statistics for tasks and all their children, the following values may be displayed:
UID The real user identification number of the task which is being monitored together with its children.
USER The name of the real user owning the task which is being monitored together with its children.
PID The identification number of the task which is being monitored together with its children.
minflt-nr
Total number of minor faults made by the task and all its children, and collected during the interval
of time.
majflt-nr
Total number of major faults made by the task and all its children, and collected during the interval
of time.
Command
The command name of the task which is being monitored together with its children.
-s Report stack utilization. The following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
StkSize
The amount of memory in kibibytes reserved for the task as stack, but not necessarily used.
StkRef The amount of memory in kibibytes used as stack, referenced by the task.
Command
The command name of the task.
-T { TASK | CHILD | ALL }
This option specifies what has to be monitored by the pidstat command. The TASK keyword indicates that statis‐
tics are to be reported for individual tasks (this is the default option) whereas the CHILD keyword indicates
that statistics are to be globally reported for the selected tasks and all their children. The ALL keyword in‐
dicates that statistics are to be reported for individual tasks and globally for the selected tasks and their
children.
Note: Global statistics for tasks and all their children are not available for all options of pidstat. Also
these statistics are not necessarily relevant to current time interval: The statistics of a child process are
collected only when it finishes or it is killed.
-t Also display statistics for threads associated with selected tasks.
This option adds the following values to the reports:
TGID The identification number of the thread group leader.
TID The identification number of the thread being monitored.
-U [ username ]
Display the real user name of the tasks being monitored instead of the UID. If username is specified, then
only tasks belonging to the specified user are displayed.
-u Report CPU utilization.
When reporting statistics for individual tasks, the following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
%usr Percentage of CPU used by the task while executing at the user level (application), with or without
nice priority. Note that this field does NOT include time spent running a virtual processor.
%system
Percentage of CPU used by the task while executing at the system level (kernel).
%guest Percentage of CPU spent by the task in virtual machine (running a virtual processor).
%wait Percentage of CPU spent by the task while waiting to run.
%CPU Total percentage of CPU time used by the task. In an SMP environment, the task's CPU usage will be di‐
vided by the total number of CPU's if option -I has been entered on the command line.
CPU Processor number to which the task is attached.
Command
The command name of the task.
When reporting global statistics for tasks and all their children, the following values may be displayed:
UID The real user identification number of the task which is being monitored together with its children.
USER The name of the real user owning the task which is being monitored together with its children.
PID The identification number of the task which is being monitored together with its children.
usr-ms Total number of milliseconds spent by the task and all its children while executing at the user level
(application), with or without nice priority, and collected during the interval of time. Note that this
field does NOT include time spent running a virtual processor.
system-ms
Total number of milliseconds spent by the task and all its children while executing at the system level
(kernel), and collected during the interval of time.
guest-ms
Total number of milliseconds spent by the task and all its children in virtual machine (running a vir‐
tual processor).
Command
The command name of the task which is being monitored together with its children.
-V Print version number then exit.
-v Report values of some kernel tables. The following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
threads
Number of threads associated with current task.
fd-nr Number of file descriptors associated with current task.
Command
The command name of the task.
-w Report task switching activity (kernels 2.6.23 and later only). The following values may be displayed:
UID The real user identification number of the task being monitored.
USER The name of the real user owning the task being monitored.
PID The identification number of the task being monitored.
cswch/s
Total number of voluntary context switches the task made per second. A voluntary context switch occurs
when a task blocks because it requires a resource that is unavailable.
nvcswch/s
Total number of non voluntary context switches the task made per second. An involuntary context switch
takes place when a task executes for the duration of its time slice and then is forced to relinquish
the processor.
Command
The command name of the task.
ENVIRONMENT
The pidstat command takes into account the following environment variables:
S_COLORS
By default statistics are displayed in color when the output is connected to a terminal. Use this variable to
change the settings. Possible values for this variable are never, always or auto (the latter is equivalent to
the default settings).
Please note that the color (being red, yellow, or some other color) used to display a value is not indicative
of any kind of issue simply because of the color. It only indicates different ranges of values.
S_COLORS_SGR
Specify the colors and other attributes used to display statistics on the terminal. Its value is a colon-sep‐
arated list of capabilities that defaults to I=32;22:N=34;1:W=35;1:X=31;1:Z=34;22. Supported capabilities
are:
I= SGR (Select Graphic Rendition) substring for item values like PID, UID or CPU number.
N= SGR substring for non-zero statistics values and for tasks names.
W= (or M=)
SGR substring for percentage values in the range from 75% to 90% (or in the range 10% to 25% depending
on the metric's meaning).
X= (or H=)
SGR substring for percentage values greater than or equal to 90% (or lower than or equal to 10% depend‐
ing on the metric's meaning).
Z= SGR substring for zero values and for threads names.
S_TIME_FORMAT
If this variable exists and its value is ISO then the current locale will be ignored when printing the date in
the report header. The pidstat command will use the ISO 8601 format (YYYY-MM-DD) instead. The timestamp will
also be compliant with ISO 8601 format.
EXAMPLES
pidstat 2 5
Display five reports of CPU statistics for every active task in the system at two second intervals.
pidstat -r -p 1643 2 5
Display five reports of page faults and memory statistics for PID 1643 at two second intervals.
pidstat -C "fox|bird" -r -p ALL
Display global page faults and memory statistics for all the processes whose command name includes the string
"fox" or "bird".
pidstat -T CHILD -r 2 5
Display five reports of page faults statistics at two second intervals for the child processes of all tasks in
the system. Only child processes with non-zero statistics values are displayed.
BUGS
/proc filesystem must be mounted for the pidstat command to work.
Although pidstat displays units corresponding to kilobytes (kB), megabytes (MB)..., it actually uses kibibytes (kiB),
mebibytes (MiB)... A kibibyte is equal to 1024 bytes, and a mebibyte is equal to 1024 kibibytes.
FILES
/proc contains various files with system statistics.
AUTHOR
Sebastien Godard (sysstat orange.fr)
SEE ALSO
sar(1), top(1), ps(1), mpstat(1), iostat(1), vmstat(8)
https://github.com/sysstat/sysstat
https://sysstat.github.io/
Linux JANUARY 2025 PIDSTAT(1)