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
       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 select-
       ing 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 following 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 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.

              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 displayed by option -u ) should be divided by the total number  of  proces-
              sors.

       -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 indi-
              cates 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 second, those which have not required loading a memory 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 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 children, the following values are displayed:

              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 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, referenced 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 statistics 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 num-
                     ber 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 are displayed:

              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  col-
                     lected 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 processor).

              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 variable:

       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 displayed.

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)