PIDSTAT(1)		      Linux User's Manual		    PIDSTAT(1)



NAME
       pidstat - Report statistics for Linux tasks.

SYNOPSIS
       pidstat	[  -C  comm  ] [ -d ] [ -h ] [ -I ] [ -l ] [ -p { pid [,...] |
       SELF | ALL } ] [ -r ] [ -s ] [ -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.
	      This string can be a regular expression.

       -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.

       -h     Display  all  activities	horizontally on a single line. This is
	      intended to make it easier to be parsed by other programs.

       -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.

       -l     Display the process command name and all its arguments.

       -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.

	      %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 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.

       -s     Report stack utilization.	 The following values are displayed:

	      PID
		     The identification number of the task being monitored.

	      StkSize
		     The amount of memory in kilobytes reserved for  the  task
		     as stack, but not necessarily used.

	      StkRef
		     The  amount  of memory in kilobytes used as stack, refer-
		     enced by the task.

	      Command
		     The command name of the task.

       -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.

       -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.


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 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 ALSO
       sar(1), top(1), ps(1), mpstat(1), iostat(1), vmstat(8)

       http://pagesperso-orange.fr/sebastien.godard/



Linux				  AUGUST 2011			    PIDSTAT(1)