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

       top - display top CPU processes

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

       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  interac-
	    tive 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 con-
	    figuration file.

       q    This causes top to refresh without any delay. If the caller has superuser privileges,
	    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 instead of individual CPUs. This  option  only  affects  SMP

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

       H    Show all threads.

       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 num-
	    ber 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
	    Shows the percentage of CPU time in user mode, system mode, niced tasks,  iowait  and
	    idle.   (Niced  tasks  are	only  those whose nice value is positive.)  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 com-

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

       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.

	    The code size of the task. This gives strange values for kernel processes and is bro-
	    ken for ELF processes.

	    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 inten-
	    tionally  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.

	    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  unin-
	    terruptible  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).

	    depending on the availability 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 per-
	    centage of total CPU time per processor.

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

	    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 pro-
	    cesses 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 separate 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

       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  com-
	    mand is not available in secure mode.

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

       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 configu-
	    ration file.

The Field and Order Screens
       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 corre-
       sponding 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
       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-
       non-privileged 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 configura-
       tion 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.

       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  cumula-
       tive  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.

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

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

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

       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 <john-
       sonm@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 ids.

       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

       Michael K. Johnson <johnsonm@redhat.com> is now the maintainer.

       Please send bug reports to <procps-list@redhat.com>

Linux					    Feb 1 1993					   TOP(1)
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