pidstat


SYNOPSIS
       pidstat  [  -C  comm  ] [ -d ] [ -h ] [ -I ] [ -l ] [ -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.

       -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 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:
              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.



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                            DECEMBER 2008                      PIDSTAT(1)
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