PIDSTAT(1) Linux User's Manual PIDSTAT(1)NAMEpidstat - Report statistics for Linux tasks.
SYNOPSISpidstat [ -C comm ] [ -d ] [ -I ] [ -p { pid | SELF | ALL } ] [ -r ] [
-t ] [ -T { TASK | CHILD | ALL } ] [ -u ] [ -V ] [ -w ] [ interval [
count ] ]
DESCRIPTION
The pidstat command is used for monitoring individual tasks currently
being managed by the Linux kernel. It writes to standard output activ‐
ities 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 below.
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 parameter 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 activity.
OPTIONS-C comm
Display only tasks whose command name includes the string comm.
-d Report I/O statistics (kernels 2.6.20 and later only). The fol‐
lowing values are displayed:
PID
The identification number of the task being monitored.
kB_rd/s
Number of kilobytes the task has caused to be read from
disk per second.
kB_wr/s
Number of kilobytes the task has caused, or shall cause
to be written to disk per second.
kB_ccwr/s
Number of kilobytes whose writing to disk has been can‐
celled by the task. This may occur when the task trun‐
cates some dirty pagecache. In this case, some IO which
another task has been accounted for will not be happen‐
ing.
Command
The command name of the task.
-I In an SMP environment, indicate that tasks CPU usage (as dis‐
played by option -u ) should be divided by the total number of
processors.
-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 page faults and memory utilization.
When reporting statistics for individual tasks, the following
values are displayed:
PID
The identification number of the task being monitored.
minflt/s
Total number of minor faults the task has made per sec‐
ond, those which have not required loading a memory page
from disk.
majflt/s
Total number of major faults the task has made per sec‐
ond, those which have required loading a memory page from
disk.
VSZ
Virtual Size: The virtual memory usage of entire task in
kilobytes.
RSS
Resident Set Size: The non-swapped physical memory used
by the task in kilobytes.
Command
The command name of the task.
When reporting global statistics for tasks and all their chil‐
dren, the following values are displayed:
PID
The identification number of the task which is being mon‐
itored 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.
-t Also display statistics for threads associated with selected
tasks.
This option adds the following value to the reports:
TID
The identification number of the thread being monitored.
-T { TASK | CHILD | ALL }
This option specifies what has to be monitored by the pidstat
command. The TASK keyword indicates that statistics 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 indicates 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 statis‐
tics of a child process are collected only when it finishes or
it is killed.
-u Report CPU utilization.
When reporting statistics for individual tasks, the following
values are displayed:
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).
%CPU
Total percentage of CPU time used by the task. In an SMP
environment, the task's CPU usage will be divided 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 chil‐
dren, the following values are displayed:
PID
The identification number of the task which is being mon‐
itored together with its children.
usr-ms
Total number of milliseconds spent by the task and all
its children while executing at the user level (applica‐
tion), with or without nice priority, and collected dur‐
ing 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 (ker‐
nel), 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 virtual pro‐
cessor).
Command
The command name of the task which is being monitored
together with its children.
-V Print version number then exit.
-w Report task switching activity (kernels 2.6.23 and later only).
The following values are displayed:
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. A 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 vari‐
able:
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.
EXAMPLESpidstat 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-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 dis‐
played.
BUGS
/proc filesystem must be mounted for the pidstat command to work.
FILES
/proc contains various files with system statistics.
AUTHOR
Sebastien Godard (sysstat <at> orange.fr)
SEE ALSOsar(1), top(1), ps(1), mpstat(1), iostat(1), vmstat(8)
http://pagesperso-orange.fr/sebastien.godard/
Linux JULY 2008 PIDSTAT(1)
