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NAME    [Toc]    [Back]

       top - display top CPU processes

SYNOPSIS    [Toc]    [Back]

       top [-] [d delay] [p pid] [q] [c] [C] [S] [s] [i] [n iter] [b]

DESCRIPTION    [Toc]    [Back]

       top  provides  an  ongoing look at processor activity in real time.  It
       displays a listing of the most CPU-intensive tasks on the  system,  and
       can  provide  an  interactive interface for manipulating processes.  It
       can sort the tasks by CPU usage, memory usage and runtime.  can be better
  configured than the standard top from the procps suite.  Most features
 can either be selected by an interactive command or by specifying
       the  feature  in  the  personal	or system-wide configuration file. See
       below for more information.


       d    Specifies the delay between screen updates.  You can  change  this
	    with the s interactive command.

       p    Monitor  only  processes  with given process id.  This flag can be
	    given up to twenty times. This option is neither available	interactively
 nor can it be put into the configuration file.

       q    This  causes  top  to refresh without any delay. If the caller has
	    superuser priviledges, top runs with the highest  possible	priority.

       S    Specifies  cumulative  mode, where each process is listed with the
	    CPU time that it as well as its dead children has spent.  This  is
	    like  the  -S  flag  to  ps(1).  See the discussion below of the S
	    interactive command.

       s    Tells top to run in secure mode.  This  disables  the  potentially
	    dangerous  of  the interactive commands (see below).  A secure top
	    is a nifty thing to leave running on a spare terminal.

       i    Start top ignoring any idle or zombie processes. See the  interactive
 command i below.

       C    display  total  CPU  states  in  addition to individual CPUs. This
	    option only affects SMP systems.

       c    display command line instead of the command name only. The default
	    behaviour has been changed as this seems to be more useful.

       n    Number  of iterations. Update the display this number of times and
	    then exit.

       b    Batch mode. Useful for sending output from top to  other  programs
	    or	to  a  file.   In  this mode, top will not accept command line
	    input.  It	runs  until  it  produces  the	number	of  iterations
	    requested  with the n option or until killed. Output is plain text
	    suitable for display on a dumb terminal.


       top displays a variety of information about the processor  state.   The
       display	is updated every 5 seconds by default, but you can change that
       with the d command-line option or the s interactive command.

	    This line displays the time the system has been up, and the  three
	    load  averages  for the system.  The load averages are the average
	    number of process ready to run during the last 1, 5  and  15  minutes.
  This line is just like the output of uptime(1).  The uptime
	    display may be toggled by the interactive l command.

	    The total number of processes running at  the  time  of  the  last
	    update.   This  is also broken down into the number of tasks which
	    are running, sleeping,  stopped,  or  undead.  The	processes  and
	    states display may be toggled by the t interactive command.

       CPU states    [Toc]    [Back]
	    Shows  the percentage of CPU time in user mode, system mode, niced
	    tasks, and idle.  (Niced tasks are only those whose nice value  is
	    negative.)	Time spent in niced tasks will also be counted in system
 and user time, so the total will be more than 100%.  The  processes
 and states display may be toggled by the t interactive command.

       Mem  Statistics on memory usage, including total available memory, free
	    memory,  used  memory, shared memory, and memory used for buffers.
	    The display of memory information may be toggled by the m interactive

       Swap Statistics	on  swap  space, including total swap space, available
	    swap space, and used swap space.  This and Mem are just  like  the
	    output of free(1).

       PID  The process ID of each task.

       PPID The parent process ID each task.

       UID  The user ID of the task's owner.

       USER The user name of the task's owner.

       PRI  The priority of the task.

       NI   The  nice value of the task.  Negative nice values are higher priority.

       SIZE The size of the task's code plus data plus stack space,  in  kilobytes,
 is shown here.

       TSIZE    [Toc]    [Back]
	    The  code  size  of the task. This gives strange values for kernel
	    processes and is broken for ELF processes.

       DSIZE    [Toc]    [Back]
	    Data + Stack size. This is broken for ELF processes.

       TRS  Text resident size.

       SWAP Size of the swapped out part of the task.

       D    Size of pages marked dirty.

       LC   Last used processor.  (That this changes from time to time is  not
	    a  bug;  Linux intentionally uses weak affinity.  Also notice that
	    the very act of running top may break weak affinity and cause more
	    processes  to  change  current CPU more often because of the extra
	    demand for CPU time.)

       RSS  The total amount of physical memory used by  the  task,  in  kilobytes,
  is	shown  here.  For ELF processes used library pages are
	    counted here, for a.out processes not.

       SHARE    [Toc]    [Back]
	    The amount of shared memory used by the task is shown in this column.

       STAT The  state	of  the  task is shown here. The state is either S for
	    sleeping, D for uninterruptible sleep, R for running, Z  for  zombies,
  or  T  for  stopped or traced. These states are modified by
	    trailing < for a process with negative nice value, N for a process
	    with  positive  nice value, W for a swapped out process (this does
	    not work correctly for kernel processes).

       WCHAN    [Toc]    [Back]
	    depending on the availablity of  either  /boot/psdatabase  or  the
	    kernel  link  map  /boot/System.map  this shows the address or the
	    name of the kernel function the task currently is sleeping in.

       TIME Total CPU time the task has used since it started.	If  cumulative
	    mode  is on, this also includes the CPU time used by the process's
	    children which have died.  You can set cumulative mode with the  S
	    command  line  option or toggle it with the interactive command S.
	    The header line will then be changed to CTIME.

       %CPU The task's share of the CPU time since  the  last  screen  update,
	    expressed as a percentage of total CPU time per processor.

       %MEM The task's share of the physical memory.

       COMMAND    [Toc]    [Back]
	    The task's command name, which will be truncated if it is too long
	    to be displayed on one line.  Tasks in memory  will  have  a  full
	    command line, but swapped-out tasks will only have the name of the
	    program in parentheses (for example, "(getty)").

       A , WP
	    these fields from the kmem top are not supported.


       Several single-key commands are recognized while top is running.   Some
       are disabled if the s option has been given on the command line.

	    Immediately updates the display.

       ^L   Erases and redraws the screen.

       h or ?
	    Displays a help screen giving a brief summary of commands, and the
	    status of secure and cumulative modes.

       k    Kill a process.  You will be prompted for the PID of the task, and
	    the signal to send to it.  For a normal kill, send signal 15.  For
	    a sure, but rather abrupt, kill, send signal 9.  The default  signal,
  as with kill(1), is 15, SIGTERM.  This command is not available
 in secure mode.

       i    Ignore idle and zombie processes.  This is a toggle switch.

       I    Toggle between Solaris (CPU percentage divided by total number  of
	    CPUs)  and	Irix  (CPU  percentage	calculated solely by amount of
	    time) views.  This is a toggle switch that affects only  SMP  systems.

       n or #
	    Change  the  number of processes to show.  You will be prompted to
	    enter the number.  This overrides automatic determination  of  the
	    number  of	processes  to show, which is based on window size measurement.
  If 0 is specified, then top will show as many processes
	    as will fit on the screen; this is the default.

       q    Quit.

       r    Re-nice  a process.  You will be prompted for the PID of the task,
	    and the value to nice it to.  Entering a positve value will  cause
	    a  process	to be niced to negative values, and lose priority.  If
	    root is running top, a negative value can be  entered,  causing  a
	    process  to get a higher than normal priority.  The default renice
	    value is 10.  This command is not available in secure mode.

       S    This toggles cumulative mode, the equivalent of ps -S, i.e.,  that
	    CPU  times	will  include  a process's defunct children.  For some
	    programs, such as compilers,  which  work  by  forking  into  many
	    seperate  tasks,  normal mode will make them appear less demanding
	    than they actually are.  For others, however, such as  shells  and
	    init,  this behavior is correct.  In any case, try cumulative mode
	    for an alternative view of CPU use.

       s    Change the delay between updates.  You will be prompted  to  enter
	    the  delay	time,  in seconds, between updates.  Fractional values
	    are recognized down to microseconds.  Entering 0 causes continuous
	    updates.   The  default  value is 5 seconds.  Note that low values
	    cause nearly unreadably fast displays, and greatly raise the load.
	    This command is not available in secure mode.

       f or F
	    Add fields to display or remove fields from the display. See below
	    for more information.

       o or O
	    Change order of displayed fields. See below for more  information.

       l    toggle display of load average and uptime information.

       m    toggle display of memory information.

       t    toggle display of processes and CPU states information.

       c    toggle display of command name or full command line.

       N    sort tasks by pid (numerically).

       A    sort tasks by age (newest first).

       P    sort tasks by CPU usage (default).

       M    sort tasks by resident memory usage.

       T    sort tasks by time / cumulative time.

       W    Write  current  setup to ~/.toprc.	This is the recommended way to
	    write a top configuration file.

The Field and Order Screens    [Toc]    [Back]

       After pressing f, F, o or O you will be shown a screen  specifying  the
       field  order  on  the top line and short descriptions of the field contents.
 The field order string uses the following syntax: If the	letter
       in  the filed string corresponding to a	field is upper case, the field
       will be displayed.  This is furthermore indicated  by  an  asterisk  in
       front of the field description.	The order of the fields corresponds to
       the order of the letters in the string.
	From the field select screen you can toggle the display of a field  by
       pressing the corresponding letter.
	From the order screen you may move a field to the left by pressing the
       corresponding upper case letter resp. to  the  right  by  pressing  the
       lower case one.

Configuration Files    [Toc]    [Back]

       Top  reads  it's  default  configuration from two files, /etc/toprc and
       ~/.toprc.  The global configuration file may be used  to  restrict  the
       usage  of  top to the secure mode for non-priviledged users. If this is
       desired, the file should contain a 's' to specify  secure  mode	and  a
       digit  d (2<=d<=9) for the default delay (in seconds) on a single line.
       The personal configuration file contains two lines. The first line contains
 lower and upper letters to specify which fields in what order are
       to be displayed. The letters correspond to the letters in the Fields or
       Order  screens  from top. As this is not very instructive, it is recommended
 to select fields and order in a running top process and to  save
       this  using  the W interactive command.	The second line is more interesting
 (and important). It contains information on the  other  options.
       Most  important,  if you have saved a configuration in secure mode, you
       will not get an insecure top without removing the lower	's'  from  the
       second line of your ~/.toprc.  A digit specifies the delay time between
       updates, a capital 'S' cumulative mode, a lower	'i'  no-idle  mode,  a
       capital	'I'  Irix  view. As in interactive mode, a lower 'm', 'l', and
       't' suppresses the display of memory,  uptime  resp.  process  and  CPU
       state  information.   Currently	changing the default sorting order (by
       CPU usage) is not supported.

NOTES    [Toc]    [Back]

       This proc-based top works by reading the files in the proc  filesystem,
       mounted on /proc.  If /proc is not mounted, top will not work.

       %CPU  shows  the  cputime/realtime  percentage  in  the	period of time
       between updates.  For the first update, a short delay is used, and  top
       itself  dominates the CPU usage.  After that, top will drop back, and a
       more reliable estimate of CPU usage is available.

       The SIZE and RSS fields don't count the page tables and the task_struct
       of  a  process; this is at least 12K of memory that is always resident.
       SIZE is the virtual size of the process (code+data+stack).

       Keep in mind that a process must die for its time to be recorded on its
       parent  by  cumulative  mode.  Perhaps more useful behavior would be to
       follow each process upwards, adding time, but that would be more expensive,
  possibly	prohibitively  so.  In any case, that would make top's
       behavior incompatible with ps.

FILES    [Toc]    [Back]

       /etc/toprc The global configuration file.  ~/.toprc The	personal  configuration

SEE ALSO    [Toc]    [Back]

       ps(1), free(1), uptime(1), kill(1), renice(1).

BUGS    [Toc]    [Back]

       If  the window is less than about 70x7, top will not format information
	Many fields still have problems with ELF processes.
	the help screens are not yet optimized for windows with less  than  25

AUTHOR    [Toc]    [Back]

       top  was originally written by Roger Binns, based on Branko Lankester's
       <lankeste@fwi.uva.nl>	  ps	   program.	   Robert	Nation
       <nation@rocket.sanders.lockheed.com>  re-wrote  it significantly to use
       the proc filesystem,  based  on	Michael  K.  Johnson's	<johnsonm@redhat.com>
      proc-based      ps      program.	   Michael     Shields
       <mjshield@nyx.cs.du.edu> made many changes, including secure and  cumulative
 modes and a general cleanup.  Tim Janik <timj@gtk.org> added age
       sorting and the ability to monitor  specific  processes	through  their

       Helmut Geyer <Helmut.Geyer@iwr.uni-heidelberg.de> Heavily changed it to
       include support for configurable fields and other new options, and  did
       further cleanup and use of the new readproc interface.

       The    "b"    and    "n"   options   contributed   by   George	Bonser
       <george@captech.com> for CapTech IT Services.

       Please send bug reports to <acahalan@cs.uml.edu>

Linux				  Feb 1 1993				TOP(1)
[ Back ]
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