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

NAME
       top - display Linux tasks

SYNOPSIS
       ⟨⟩
	-hvV  |	 -bcHisSMm  -d delay -n iterations [-u user | -U user] -p
       pid [, pid ...]

       The traditional switches '-' and whitespace are optional.

DESCRIPTION
       The .ie 0 .    br
	program provides a dynamic real-time view of  a	 running  system.
       It  can	display	 system	 summary information as well as a list of
       tasks currently being managed by the Linux kernel.  The	types  of
       system  summary information shown and the types, order and size of
       information displayed for tasks are all user configurable and that
       configuration can be made persistent across restarts.

       The  program  provides a limited interactive interface for process
       manipulation as well as a much more extensive interface	for  per‐
       sonal  configuration   --  encompassing every aspect of its opera‐
       tion.  And while .ie 0 .	   br
	is referred to throughout this document, you are free to name the
       program anything you wish.  That new name, possibly an alias, will
       then be reflected on top's display and used when reading and writ‐
       ing a configuration file.

OVERVIEW
   Documentation
       The remaining Table of Contents
	   1. COMMAND-LINE Options
	   2. FIELDS / Columns
	      a. DESCRIPTIONS of Fields
	      b. SELECTING and ORDERING Columns
	   3. INTERACTIVE Commands
	      a. GLOBAL Commands
	      b. SUMMARY Area Commands
	      c. TASK Area Commands
	      d. COLOR Mapping
	   4. ALTERNATE-DISPLAY Mode
	      a. WINDOWS Overview
	      b. COMMANDS for Windows
	   5. FILES
	      a. SYSTEM Configuration File
	      b. PERSONAL Configuration File
	   6. STUPID TRICKS Sampler
	      a. Kernel Magic
	      b. Bouncing Windows
	      c. The Big Bird Window
	   7. BUGS, 8. HISTORY Former top, 9. AUTHOR, 10. SEE ALSO

   Operation
       When  operating	top, the two most important keys are help ('h' or
       '?') and quit ('q') key.	 Alternatively, you could simply use  the
       traditional interrupt key ('^C') when you're done.

       When  you  start	 top for the first time, you'll be presented with
       the  traditional	 screen	 elements:  1)	Summary	 Area;	2)   Mes‐
       sage/Prompt  Line;  3)  Columns Header; 4) Task Area.  There will,
       however, be some differences when compared to the former top.

       Highlighting
	  Summary_Area: There is no highlighting for load/uptime and only
	  values are highlighted for other elements.

	  Task_Area: Tasks running (or ready to run) will be highlighted,
	  and bold is only one way of emphasizing such processes.

       Content/Labels
	  Summary_Area: The program name is shown, perhaps a  symlink  or
	  alias.   The	Cpu(s)	state label hints at other possibilities.
	  The memory stats use a lower case 'k'.

	  Columns_Header: Will show a new field and some changed  labels.
	  More new fields will be found as you customize your top.

       Note: the width of top's display will be limited to 512 positions.
       Displaying all fields requires a minimum of 160	characters.   The
       remaining width could be used for the 'Command' column.

   Startup Defaults
       The  following startup defaults assume no configuration file, thus
       no user customizations.	Even so, items	shown  with  an	 asterisk
       ('*') could be overridden through the command-line.

	   Global_defaults
	      'A' - Alt display	     Off (full-screen)
	    * 'd' - Delay time	     3.0 seconds
	      'I' - Irix mode	     On	 (no, 'solaris' smp)
	    * 'p' - PID monitoring   Off
	    * 's' - Secure mode	     Off (unsecured)
	      'B' - Bold disable     Off
	   Summary_Area_defaults
	      'l' - Load Avg/Uptime  On	 (thus program name)
	      't' - Task/Cpu states  On	 (1+1 lines, see '1')
	      'm' - Mem/Swap usage   On	 (2 lines worth)
	      '1' - Single Cpu	     On	 (thus 1 line if smp)
	   Task_Area_defaults
	      'b' - Bold hilite	     On	 (not 'reverse')
	    * 'c' - Command line     Off (name, not cmdline)
	    * 'H' - Threads	     Off (show all threads)
	    * 'i' - Idle tasks	     On	 (show all tasks)
	      'R' - Reverse sort     On	 (pids high-to-low)
	    * 'S' - Cumulative time  Off (no, dead children)
	      'x' - Column hilite    Off (no, sort field)
	      'y' - Row hilite	     On	 (yes, running tasks)
	      'z' - color/mono	     Off (no, colors)

1. COMMAND-LINE Options
       The command-line syntax for top consists of:

	    -hvV | -bcHisSMm -d delay -n iterations [-u	 user  | -U user]
       -p pid [,pid...]

       The typically mandatory switches ('-')  and  even  whitespace  are
       completely optional.

       -b : Batch mode operation
	    Starts top in 'Batch mode', which could be useful for sending
	    output from top to other programs or  to  a	 file.	 In  this
	    mode, top will not accept input and runs until the iterations
	    limit you've set with the '-n' command-line option	or  until
	    killed.

       -c : Command line/Program name toggle
	    Starts  top	 with  the  last  remembered  'c' state reversed.
	    Thus, if top was displaying command	 lines,	 now  that  field
	    will  show program names, and visa versa.  See the 'c' inter‐
	    active command for additional information.

       -d : Delay time interval as:  -d ss.tt (seconds.tenths)
	    Specifies the delay between screen updates, and overrides the
	    corresponding  value  in one's personal configuration file or
	    the startup default.  Later this can be changed with the  'd'
	    or 's' interactive commands.

	    Fractional	seconds are honored, but a negative number is not
	    allowed.  In all cases, however, such changes are  prohibited
	    if	top  is running in 'Secure mode', except for root (unless
	    the 's' command-line option was used).  For additional infor‐
	    mation  on	'Secure	 mode' see topic 5a. SYSTEM Configuration
	    File.

       -h : Help
	    Show library version and the usage prompt, then quit.

       -M : Detect memory units
	    Show memory units (k/M/G) and display floating  point  values
	    in the memory summary.

       -m : Sort by memory usage
	    This switch makes top to sort the processes by allocated mem‐
	    ory

       -H : Threads toggle
	    Starts top with the last remembered 'H' state reversed.  When
	    this  toggle is On, all individual threads will be displayed.
	    Otherwise, top displays a  summation  of  all  threads  in	a
	    process.

       -i : Idle Processes toggle
	    Starts top with the last remembered 'i' state reversed.  When
	    this toggle is Off, tasks that are idled or zombied will  not
	    be displayed.

       -n : Number of iterations limit as:  -n number
	    Specifies  the  maximum  number of iterations, or frames, top
	    should produce before ending.

       -u : Monitor by user as:	 -u somebody
	    Monitor only processes with an effective  UID  or  user  name
	    matching that given.

       -U : Monitor by user as:	 -U somebody
	    Monitor  only processes with a UID or user name matching that
	    given.  This matches real, effective, saved,  and  filesystem
	    UIDs.

       -p : Monitor PIDs as:  -pN1 -pN2 ...  or	 -pN1, N2 [,...]
	    Monitor  only  processes  with  specified  process IDs.  This
	    option can be given up to 20 times,	 or  you  can  provide	a
	    comma  delimited  list  with up to 20 pids.	 Co-mingling both
	    approaches is permitted.

	    This is a command-line option only.	 And should you	 wish  to
	    return  to	normal operation, it is not necessary to quit and
	    and restart top  --	 just issue the '=' interactive command.

       -s : Secure mode operation
	    Starts top with secure mode forced, even for root.	This mode
	    is	far  better  controlled	 through the system configuration
	    file (see topic 5. FILES).

       -S : Cumulative time mode toggle
	    Starts top with the last remembered 'S' state reversed.  When
	    'Cumulative	 mode' is On, each process is listed with the cpu
	    time that it and its dead children have used.   See	 the  'S'
	    interactive command for additional information regarding this
	    mode.

       -v : Version
	    Show library version and the usage prompt, then quit.

       -M : Detect memory units
	    Show memory units (k/M/G) and display floating  point  values
	    in the memory summary.

2. FIELDS / Columns
   2a. DESCRIPTIONS of Fields
       Listed  below are top's available fields.  They are always associ‐
       ated with the letter shown, regardless of  the  position	 you  may
       have  established for them with the 'o' (Order fields) interactive
       command.

       Any field is selectable as the sort field, and you control whether
       they are sorted high-to-low or low-to-high.  For additional infor‐
       mation on sort provisions see topic 3c. TASK Area Commands.

       a: PID  --  Process Id
	  The task's unique process ID, which periodically wraps,  though
	  never restarting at zero.

       b: PPID	--  Parent Process Pid
	  The process ID of a task's parent.

       c: RUSER	 --  Real User Name
	  The real user name of the task's owner.

       d: UID  --  User Id
	  The effective user ID of the task's owner.

       e: USER	--  User Name
	  The effective user name of the task's owner.

       f: GROUP	 --  Group Name
	  The effective group name of the task's owner.

       g: TTY  --  Controlling Tty
	  The  name  of	 the  controlling  terminal.  This is usually the
	  device (serial port, pty, etc.)  from	 which	the  process  was
	  started,  and	 which	it  uses for input or output.  However, a
	  task need not be associated with  a  terminal,  in  which  case
	  you'll see '?' displayed.

       h: PR  --  Priority
	  The priority of the task.

       i: NI  --  Nice value
	  The nice value of the task.  A negative nice value means higher
	  priority, whereas a positive nice value means	 lower	priority.
	  Zero	in  this field simply means priority will not be adjusted
	  in determining a task's dispatchability.

       j: P  --	 Last used CPU (SMP)
	  A number representing the last used processor.  In a	true  SMP
	  environment this will likely change frequently since the kernel
	  intentionally uses weak affinity.  Also, the very act	 of  run‐
	  ning	top may break this weak affinity and cause more processes
	  to change CPUs more often (because of the extra demand for  cpu
	  time).

       k: %CPU	--  CPU usage
	  The  task's share of the elapsed CPU time since the last screen
	  update, expressed as a percentage of total CPU time.	In a true
	  SMP  environment,  if	 'Irix	mode' is Off, top will operate in
	  'Solaris mode' where a task's cpu usage will be divided by  the
	  total number of CPUs.	 You toggle 'Irix/Solaris' modes with the
	  'I' interactive command.

       l: TIME	--  CPU Time
	  Total CPU time the task has used since it started.  When 'Cumu‐
	  lative  mode'	 is  On, each process is listed with the cpu time
	  that it and its dead children has used.  You toggle 'Cumulative
	  mode'	 with 'S', which is a command-line option and an interac‐
	  tive command.	 See the 'S' interactive command  for  additional
	  information regarding this mode.

       m: TIME+	 --  CPU Time, hundredths
	  The  same  as	 'TIME',  but reflecting more granularity through
	  hundredths of a second.

       n: %MEM	--  Memory usage (RES)
	  A task's currently used share of available physical memory.

       o: VIRT	--  Virtual Image (kb)
	  The total amount of  virtual	memory	used  by  the  task.   It
	  includes  all	 code,	data and shared libraries plus pages that
	  have been swapped out. (Note: you  can  define  the  STATSIZE=1
	  environment  variable	 and the VIRT will be calculated from the
	  /proc/#/state VmSize field.)

	  VIRT = SWAP + RES.

       p: SWAP	--  Non-resident size (kb)
	  The non-resident portion of a task's address space.

       q: RES  --  Resident size (kb)
	  The non-swapped physical memory a task has used.

	  RES = CODE + DATA.

       r: CODE	--  Code size (kb)
	  The amount of physical memory devoted to executable code,  also
	  known as the 'text resident set' size or TRS.

       s: DATA	--  Data+Stack size (kb)
	  The  amount of physical memory devoted to other than executable
	  code, also known as the 'data resident set' size or DRS.

       t: SHR  --  Shared Mem size (kb)
	  The amount of shared memory used by a task.  It simply reflects
	  memory that could be potentially shared with other processes.

       u: nFLT	--  Page Fault count
	  The  number of major page faults that have occurred for a task.
	  A page fault occurs when a process attempts  to  read	 from  or
	  write	 to  a	virtual page that is not currently present in its
	  address space.  A major page	fault  is  when	 disk  access  is
	  involved in making that page available.

       v: nDRT	--  Dirty Pages count
	  The  number  of  pages  that have been modified since they were
	  last written to disk.	 Dirty pages  must  be	written	 to  disk
	  before  the  corresponding physical memory location can be used
	  for some other virtual page.

       w: S  --	 Process Status
	  The status of the task which can be one of:
	     'D' = uninterruptible sleep
	     'R' = running
	     'S' = sleeping
	     'T' = traced or stopped
	     'Z' = zombie

	  Tasks shown as running should be more properly  thought  of  as
	  'ready  to run'  --  their task_struct is simply represented on
	  the Linux run-queue.	Even without a true SMP machine, you  may
	  see  numerous	 tasks	in  this  state	 depending on top's delay
	  interval and nice value.

       x: Command  --  Command line or Program name
	  Display the command line used to start a task or  the	 name  of
	  the  associated  program.   You toggle between command line and
	  name with 'c', which is  both	 a  command-line  option  and  an
	  interactive command.

	  When	you've chosen to display command lines, processes without
	  a command line (like kernel threads) will be	shown  with  only
	  the program name in parentheses, as in this example:
		( mdrecoveryd )

	  Either  form	of  display is subject to potential truncation if
	  it's too long to fit in this field's current width.  That width
	  depends upon other fields selected, their order and the current
	  screen width.

	  Note: The 'Command' field/column is unique, in that it  is  not
	  fixed-width.	When displayed, this column will be allocated all
	  remaining screen width (up to the maximum  512  characters)  to
	  provide  for the potential growth of program names into command
	  lines.

       y: WCHAN	 --  Sleeping in Function
	  Depending on the availability of the	kernel	link  map  ('Sys‐
	  tem.map'),  this field will show the name or the address of the
	  kernel function in which the task is currently sleeping.   Run‐
	  ning tasks will display a dash ('-') in this column.

	  Note:	 By  displaying this field, top's own working set will be
	  increased by over 700Kb.  Your  only	means  of  reducing  that
	  overhead will be to stop and restart top.

       z: Flags	 --  Task Flags
	  This	column	represents  the	 task's	 current scheduling flags
	  which are expressed in hexadecimal notation and with zeros sup‐
	  pressed.     These   flags   are   officially	  documented   in
	  <linux/sched.h>.  Less formal documentation can also	be  found
	  on the 'Fields select' and 'Order fields' screens.

   2b. SELECTING and ORDERING Columns
       After pressing the interactive commands 'f' (Fields select) or ´o'
       (Order fields) you will be shown a screen containing  the  current
       fields string followed by names and descriptions for all fields.

       Here  is	 a  sample  fields  string  from  one  of top's four win‐
       dows/field groups and an explanation of the conventions used:

       -  Sample fields string:
	     ANOPQRSTUVXbcdefgjlmyzWHIK

       -  The order of displayed fields corresponds to the order  of  the
	  letters in that string.

       -  If the letter is upper case the corresponding field itself will
	  then be shown as part of the task display (screen width permit‐
	  ting).   This	 will  also  be	 indicated  by a leading asterisk
	  ('*'), as in this excerpt:
	      ...
	      * K: %CPU	      = CPU usage
		l: TIME	      = CPU Time
		m: TIME+      = CPU Time, hundredths
	      * N: %MEM	      = Memory usage (RES)
	      * O: VIRT	      = Virtual Image (kb)
	      ...

       Fields select screen  --	 the 'f' interactive command
	  You toggle the display of a field by simply pressing the corre‐
	  sponding letter.

       Order fields screen  --	the 'o' interactive command
	  You  move  a	field  to  the left by pressing the corresponding
	  upper case letter and to the right with the lower case letter.

3. INTERACTIVE Commands
       Listed below is a brief index of commands within categories.  Some
       commands	 appear	 more  than  once  --  their meaning or scope may
       vary depending on the context in which they are issued.

	 3a. GLOBAL_Commands
	       <Ret/Sp> ?, =, A, B, d, G, h, I, k, q, r, s, W, Z
	 3b. SUMMARY_Area_Commands
	       l, m, t, 1
	 3c. TASK_Area_Commands
	       Appearance:  b, x, y, z
	       Content:	    c, f, H, o, S, u
	       Size:	    #, i, n
	       Sorting:	    <, >, F, O, R
	 3d. COLOR_Mapping
	       <Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
	 4b. COMMANDS_for_Windows
	       -, _, =, +, A, a, G, g, w

   3a. GLOBAL Commands
       The global interactive  commands	 are  always  available	 in  both
       full-screen  mode  and  alternate-display  mode.	 However, some of
       these interactive commands  are	not  available	when  running  in
       'Secure mode'.

       If  you	wish  to know in advance whether or not your top has been
       secured, simply ask for help and view the system	 summary  on  the
       second line.

	 <Enter> or <Space> :Refresh_Display
	      These  commands  do nothing, they are simply ignored.  How‐
	      ever, they will awaken top and  following	 receipt  of  any
	      input the entire display will be repainted.

	      Use either of these keys if you have a large delay interval
	      and wish to see current status,

	 ´?´ or ´h´ :Help
	      There are two help levels available.  The first  will  pro‐
	      vide  a reminder of all the basic interactive commands.  If
	      top is secured, that screen will be abbreviated.

	      Typing 'h' or '?' on that help screen will take you to help
	      for those interactive commands applicable to alternate-dis‐
	      play mode.

	 ´=´ :Exit_Task_Limits
	      Removes restrictions on which tasks are shown.   This  com‐
	      mand  will reverse any 'i' (idle tasks) and 'n' (max tasks)
	      commands that might be active.  It  also	provides  for  an
	      'exit'  from  PID	 monitoring.   See  the '-p' command-line
	      option for a discussion of PID monitoring.

	      When operating in alternate-display mode this command has a
	      slightly broader meaning.

	 ´A´ :Alternate_Display_Mode_toggle
	      This  command  will  switch  between  full-screen	 mode and
	      alternate-display mode.	See  topic  4.	ALTERNATE-DISPLAY
	      Mode and the 'G' interactive command for insight into ´cur‐
	      rent' windows and field groups.

	 ´B´ :Bold_Disable/Enable_toggle
	      This command will influence  use	of  the	 'bold'	 terminfo
	      capability  and  alters both the summary area and task area
	      for the ´current' window.	 While it is  intended	primarily
	      for use with dumb terminals, it can be applied anytime.

	      Note:  When this toggle is On and top is operating in mono‐
	      chrome mode, the entire display will appear as normal text.
	      Thus,  unless  the 'x' and/or 'y' toggles are using reverse
	      for emphasis, there will be  no  visual  confirmation  that
	      they are even on.

       * ´d´ or ´s´ :Change_Delay_Time_interval
	      You  will	 be prompted to enter the delay time, in seconds,
	      between display updates.

	      Fractional seconds are honored, but a  negative  number  is
	      not   allowed.	Entering  0  causes  (nearly)  continuous
	      updates, with an unsatisfactory display as the  system  and
	      tty  driver  try	to keep up with top's demands.	The delay
	      value is inversely proportional to system loading,  so  set
	      it with care.

	      If  at  any  time	 you wish to know the current delay time,
	      simply ask for help and view the system summary on the sec‐
	      ond line.

	 ´G´ :Choose_Another_Window/Field_Group
	      You will be prompted to enter a number between 1 and 4 des‐
	      ignating the window/field group which should  be	made  the
	      ´current'	 window.   You	will  soon  grow comfortable with
	      these 4 windows, especially after experimenting with alter‐
	      nate-display mode.

	 ´I´ :Irix/Solaris_Mode_toggle
	      When  operating  in  'Solaris  mode'  ('I'  toggled Off), a
	      task's cpu usage will be divided by  the	total  number  of
	      CPUs.   After  issuing  this command, you'll be informed of
	      the new state of this toggle.

	 ´u´ :select a user
	      You will be prompted for a UID or username. Only	processes
	      belonging	 to  the  selected  user  will be displayed. This
	      option matches on the effective UID.

	 ´U´ :select a user
	      You will be prompted for a UID or username. Only	processes
	      belonging	 to  the  selected  user  will be displayed. This
	      option matches on the real, effective, saved, and	 filesys‐
	      tem UID.

       * ´k´ :Kill_a_task
	      You will be prompted for a PID and then the signal to send.
	      The default signal, as reflected in the prompt, is SIGTERM.
	      However, you can send any signal, via number or name.

	      If  you  wish to abort the kill process, do one of the fol‐
	      lowing depending on your progress:
		 1) at the pid prompt, just press <Enter>
		 2) at the signal prompt, type 0

	 ´q´ :Quit

       * ´r´ :Renice_a_Task
	      You will be prompted for a PID and then the value	 to  nice
	      it  to.	Entering a positive value will cause a process to
	      lose priority.  Conversely, a negative value will	 cause	a
	      process to be viewed more favorably by the kernel.

	 ´W´ :Write_the_Configuration_File
	      This  will  save	all  of your options and toggles plus the
	      current display mode and delay time.  By issuing this  com‐
	      mand  just  before  quitting  top, you will be able restart
	      later in exactly that same state.

	 ´Z´ :Change_Color_Mapping
	      This key will take you to a separate screen where	 you  can
	      change the colors for the ´current' window, or for all win‐
	      dows.  For details regarding this interactive  command  see
	      topic 3d. COLOR Mapping.

       *  The  commands shown with an asterisk ('*') are not available in
	  'Secure mode', nor will they	be  shown  on  the  level-1  help
	  screen.

   3b. SUMMARY Area Commands
       The summary area interactive commands are always available in both
       full-screen mode and  alternate-display	mode.	They  affect  the
       beginning lines of your display and will determine the position of
       messages and prompts.

       These commands  always  impact  just  the  ´current'  window/field
       group.	See  topic 4. ALTERNATE-DISPLAY Mode and the 'G' interac‐
       tive command for insight into ´current' windows and field groups.

	 ´l´ :Toggle_Load_Average/Uptime  --  On/Off
	      This is also the line containing the program name (possibly
	      an  alias)  when operating in full-screen mode or the ´cur‐
	      rent' window name when operating in alternate-display mode.

	 ´m´ :Toggle_Memory/Swap_Usage	--  On/Off
	      This command affects two summary area lines.

	 ´t´ :Toggle_Task/Cpu_States  --  On/Off
	      This command affects from 2 to  many  summary  area  lines,
	      depending on the state of the '1' toggle and whether or not
	      top is running under true SMP.

	 ´1´ :Toggle_Single/Separate_Cpu_States	 --  On/Off
	      This command affects how the 't' command's Cpu States  por‐
	      tion  is	shown.	 Although this toggle exists primarily to
	      serve massively-parallel SMP machines, it is not restricted
	      to solely SMP environments.

	      When  you see 'Cpu(s):' in the summary area, the '1' toggle
	      is On and all cpu information is gathered in a single line.
	      Otherwise,  each	cpu  is	 displayed  separately as: 'Cpu0,
	      Cpu1, ...'

       Note: If the entire summary area has been toggled Off for any win‐
       dow,  you  would be left with just the message line.  In that way,
       you will have maximized available task rows but (temporarily) sac‐
       rificed the program name in full-screen mode or the ´current' win‐
       dow name when in alternate-display mode.

   3c. TASK Area Commands
       The  task  area	interactive  commands  are  always  available  in
       full-screen mode.

       The  task  area interactive commands are never available in alter‐
       nate-display mode if the ´current' window's task display has  been
       toggled Off (see topic 4. ALTERNATE-DISPLAY Mode).

       APPEARANCE of task window
	 The  following	 commands will also be influenced by the state of
	 the global 'B' (bold disable) toggle.

	 ´b´ :Bold/Reverse_toggle
	      This command will impact how the 'x' and	'y'  toggles  are
	      displayed.   Further,  it	 will  only  be available when at
	      least one of those toggles is On.

	 ´x´ :Column_Highlight_toggle
	      Changes highlighting for the current sort field.	You prob‐
	      ably  don't  need	 a  constant  visual reminder of the sort
	      field and top hopes that you always run with 'column  high‐
	      light' Off, due to the cost in path-length.

	      If  you forget which field is being sorted this command can
	      serve as a quick visual reminder.

	 ´y´ :Row_Highlight_toggle
	      Changes highlighting for "running" tasks.	  For  additional
	      insight into this task state, see topic 2a. DESCRIPTIONS of
	      Fields, Process Status.

	      Use of this provision provides important insight into  your
	      system's	health.	  The only costs will be a few additional
	      tty escape sequences.

	 ´z´ :Color/Monochrome_toggle
	      Switches the ´current' window between your last used  color
	      scheme  and  the	older form of black-on-white or white-on-
	      black.  This command will alter both the summary	area  and
	      task  area but does not affect the state of the 'x', 'y' or
	      'b' toggles.

       CONTENT of task window
	 ´c´ :Command_Line/Program_Name_toggle
	      This command will be honored whether or not  the	'Command'
	      column is currently visible.  Later, should that field come
	      into view, the change you applied will be seen.

	 ´f´ and ´o´ :Fields_select or Order_fields
	      These keys display separate screens where	 you  can  change
	      which fields are displayed and their order.  For additional
	      information on these interactive	commands  see  topic  2b.
	      SELECTING and ORDERING Columns.

	 ´H´ :Threads_toggle
	      When this toggle is On, all individual threads will be dis‐
	      played.  Otherwise, top displays a summation of all threads
	      in a process.

	 ´S´ :Cumulative_Time_Mode_toggle
	      When  'Cumulative	 mode' is On, each process is listed with
	      the cpu time that it and its dead children have used.

	      When Off, programs that fork into many separate tasks  will
	      appear less demanding.  For programs like 'init' or a shell
	      this is appropriate but for others, like compilers, perhaps
	      not.   Experiment	 with  two  task windows sharing the same
	      sort field but with different 'S' states and see which rep‐
	      resentation you prefer.

	      After  issuing  this command, you'll be informed of the new
	      state of this toggle.  If	 you  wish  to	know  in  advance
	      whether  or  not 'Cumulative mode' is in effect, simply ask
	      for help and view the window summary on the second line.

	 ´u´ :Show_Specific_User_Only
	      You will be prompted to enter the name of the user to  dis‐
	      play.   Thereafter,  in that task window only matching User
	      ID's will be shown, or possibly no tasks will be shown.

	      Later, if you wish to monitor  all  tasks	 again,	 re-issue
	      this  command but just press <Enter> at the prompt, without
	      providing a name.

       SIZE of task window
	 ´i´ :Idle_Processes_toggle
	      Displays all tasks or just active tasks.	When this  toggle
	      is Off, idled or zombied processes will not be displayed.

	      If this command is applied to the last task display when in
	      alternate-display mode, then it will not	affect	the  win‐
	      dow's  size,  as	all prior task displays will have already
	      been painted.

	 ´n´ or ´#´ :Set_Maximum_Tasks
	      You will be prompted to enter the number of tasks	 to  dis‐
	      play.   The lessor of your number and available screen rows
	      will be used.

	      When used in alternate-display mode, this	 is  the  command
	      that  gives  you precise control over the size of each cur‐
	      rently visible task display, except for the very last.   It
	      will  not	 affect the last window's size, as all prior task
	      displays will have already been painted.

	      Note: If you wish to increase the size of the last  visible
	      task   display   when  in	 alternate-display  mode,  simply
	      decrease the size of the task display(s) above it.

       SORTING of task window
	 For compatibility, this top supports most of the former top sort
	 keys.	 Since	this  is primarily a service to former top users,
	 these commands do not appear on any help screen.
	    command   sorted field		    supported
	      A		start time (non-display)      No
	      M		%MEM			      Yes
	      N		PID			      Yes
	      P		%CPU			      Yes
	      T		TIME+			      Yes

	 Before using any of the following sort provisions, top	 suggests
	 that  you  temporarily turn on column highlighting using the 'x'
	 interactive command.  That will help ensure that the actual sort
	 environment matches your intent.

	 The following interactive commands will only be honored when the
	 current sort field is visible.	 The sort field might not be vis‐
	 ible because:
	      1) there is insufficient Screen Width
	      2) the 'f' interactive command turned it Off

	 ´<´ :Move_Sort_Field_Left
	      Moves  the  sort column to the left unless the current sort
	      field is the first field being displayed.

	 ´>´ :Move_Sort_Field_Right
	      Moves the sort column to the right unless the current  sort
	      field is the last field being displayed.

	 The  following	 interactive  commands	will  always  be  honored
	 whether or not the current sort field is visible.

	 ´F´ or ´O´ :Select_Sort_Field
	      These keys display a separate screen where you  can  change
	      which field is used as the sort column.

	      If  a field is selected which was not previously being dis‐
	      played, it will be forced On when you  return  to	 the  top
	      display.	However, depending upon your screen width and the
	      order of your fields, this  sort	field  may  not	 be  dis‐
	      playable.

	      This  interactive command can be a convenient way to simply
	      verify the current sort field, when running top with column
	      highlighting turned Off.

	 ´R´ :Reverse/Normal_Sort_Field_toggle
	      Using  this  interactive	command you can alternate between
	      high-to-low and low-to-high sorts.

	 Note: Field sorting uses internal values, not	those  in  column
	 display.   Thus,  the	TTY  and WCHAN fields will violate strict
	 ASCII collating sequence.

   3d. COLOR Mapping
       When you issue the 'Z' interactive command, you will be	presented
       with  a	separate  screen.   That screen can be used to change the
       colors in just the ´current' window or in all four windows  before
       returning to the top display.

       Available interactive commands
	   4 upper case letters to select a target
	   8 numbers to select a color
	   normal toggles available
	       'B'	 :bold disable/enable
	       'b'	 :running tasks "bold"/reverse
	       'z'	 :color/mono
	   other commands available
	       'a'/'w'	 :apply, then go to next/prior
	       <Enter>	 :apply and exit
	       'q'	 :abandon current changes and exit

       If your use 'a' or 'w' to cycle the targeted window, you will have
       applied the color scheme that was displayed  when  you  left  that
       window.	You can, of course, easily return to any window and reap‐
       ply different colors or turn colors Off completely  with	 the  'z'
       toggle.

       The  Color Mapping screen can also be used to change the ´current'
       window/field group in either full-screen mode or alternate-display
       mode.   Whatever was targeted when 'q' or <Enter> was pressed will
       be made current as you return to the top display.

4. ALTERNATE-DISPLAY Mode
   4a. WINDOWS Overview
       Field Groups/Windows:
	      In full-screen mode there is a single window represented by
	      the entire screen.  That single window can still be changed
	      to display 1 of 4	 different  field  groups  (see	 the  'G'
	      interactive  command, repeated below).  Each of the 4 field
	      groups has a unique separately  configurable  summary  area
	      and its own configurable task area.

	      In  alternate-display mode, those 4 underlying field groups
	      can now be made visible simultaneously, or  can  be  turned
	      Off individually at your command.

	      The  summary  area will always exist, even if it's only the
	      message line.  At any given time only one summary area  can
	      be  displayed.   However, depending on your commands, there
	      could be from zero to four separate task displays currently
	      showing on the screen.

       Current Window:
	      The ´current' window is the window associated with the sum‐
	      mary area and the window to which task related commands are
	      always  directed.	  Since in alternate-display mode you can
	      toggle  the  task	 display  Off,	some  commands	might  be
	      restricted for the ´current' window.

	      A	 further  complication	arises	when you have toggled the
	      first summary area line Off.  With the loss of  the  window
	      name  (the  'l'  toggled line), you'll not easily know what
	      window is the ´current' window.

   4b. COMMANDS for Windows
	 ´-´ and ´_´ :Show/Hide_Window(s)_toggles
	      The '-' key turns the ´current' window's	task  display  On
	      and  Off.	  When	On, that task area will show a minimum of
	      the columns header you've established with the 'f' and  'o'
	      commands.	  It  will  also  reflect  any	other  task  area
	      options/toggles you've applied yielding zero or more tasks.

	      The '_' key does the same for all task displays.	In  other
	      words,  it switches between the currently visible task dis‐
	      play(s) and any task display(s) you had  toggled	Off.   If
	      all 4 task displays are currently visible, this interactive
	      command will leave the summary area  as  the  only  display
	      element.

       * ´=´ and ´+´ :Equalize_(re-balance)_Window(s)
	      The  '='	key forces the ´current' window's task display to
	      be visible.  It also reverses any 'i' (idle tasks) and  'n'
	      (max tasks) commands that might be active.

	      The  '+'	key does the same for all windows.  The four task
	      displays will reappear, evenly balanced.	 They  will  also
	      have   retained	any  customizations  you  had  previously
	      applied, except for the  'i'  (idle  tasks)  and	'n'  (max
	      tasks) commands.

       * ´A´ :Alternate_Display_Mode_toggle
	      This  command  will  switch  between  full-screen	 mode and
	      alternate-display mode.

	      The first time you issue this command, all four  task  dis‐
	      plays will be shown.  Thereafter when you switch modes, you
	      will see only the task display(s)	 you've	 chosen	 to  make
	      visible.

       * ´a´ and ´w´ :Next_Window_Forward/Backward
	      This  will  change  the  ´current'  window,  which  in turn
	      changes the window to which commands are	directed.   These
	      keys act in a circular fashion so you can reach any desired
	      ´current' window using either key.

	      Assuming the window name is visible (you have  not  toggled
	      'l'  Off),  whenever  the	 ´current'  window name loses its
	      emphasis/color, that's a reminder the task display  is  Off
	      and many commands will be restricted.

       * ´G´ :Choose_Another_Window/Field_Group
	      You will be prompted to enter a number between 1 and 4 des‐
	      ignating the window/field group which should  be	made  the
	      ´current' window.

	      In full-screen mode, this command is necessary to alter the
	      ´current' window.	 In alternate-display mode, it is  simply
	      a less convenient alternative to the 'a' and 'w' commands.

	 ´g´ :Change_Window/Field_Group_Name
	      You  will	 be  prompted for a new name to be applied to the
	      ´current' window.	 It does not require that the window name
	      be visible (the 'l' toggle to be On).

       *  The  interactive commands shown with an asterisk ('*') have use
	  beyond alternate-display mode.
	      ´=', 'A', 'G'  are always available
	      ´a', 'w'	     act the same when color mapping

5. FILES
   5a. SYSTEM Configuration File
       The presence of this file will  influence  which	 version  of  the
       'help'  screen is shown to an ordinary user.  More importantly, it
       will limit what ordinary users are allowed to do when top is  run‐
       ning.  They will not be able to issue the following commands.
	  k	    Kill a task
	  r	    Renice a task
	  d or s    Change delay/sleep interval

       The  system configuration file is not created by top.  Rather, you
       create this file manually and place it in the /etc directory.  Its
       name  must  be  'toprc' and must have no leading '.' (period).  It
       must have only two lines.

       Here is an example of the contents of /etc/toprc:
	  s	    # line 1: 'secure' mode switch
	  5.0	    # line 2: 'delay'  interval in seconds

   5b. PERSONAL Configuration File
       This file is written as '$HOME/.your-name-4-top' + 'rc'.	 Use  the
       'W' interactive command to create it or update it.

       Here is the general layout:
	  global    # line 1: the program name/alias notation
	    "	    # line 2: id,altscr,irixps,delay,curwin
	  per ea    # line a: winname,fieldscur
	  window    # line b: winflags,sortindx,maxtasks
	    "	    # line c: summclr,msgsclr,headclr,taskclr

       If  the	$HOME  variable is not present, top will try to write the
       personal configuration file to the current directory,  subject  to
       permissions.

6. STUPID TRICKS Sampler
       Many  of	 these	'tricks' work best when you give top a scheduling
       boost.  So plan on starting him with a nice value of -10, assuming
       you've got the authority.

   6a. Kernel Magic
       For these stupid tricks, top needs full-screen mode.

       -*-  The	 user  interface, through prompts and help, intentionally
	    implies that the delay interval is limited	to  tenths  of	a
	    second.   However,	you're free to set any desired delay.  If
	    you want to see Linux at his scheduling best, try a delay  of
	    .09 seconds or less.

	    For	 this experiment, under x-windows open an xterm and maxi‐
	    mize it.  Then do the following:
	      . provide a scheduling boost and tiny delay via:
		  nice -n -10 top -d.09
	      . keep sorted column highlighting Off to minimize
		path length
	      . turn On reverse row highlighting for emphasis
	      . try various sort columns (TIME/MEM work well),
		and normal or reverse sorts to bring the most
		active processes into view

	    What you'll see is a very busy Linux doing what  he's  always
	    done  for  you,  but there was no program available to illus‐
	    trate this.

       -*-  Under an xterm using  'white-on-black'  colors,  try  setting
	    top's  task color to black and be sure that task highlighting
	    is set to bold, not reverse.  Then set the delay interval  to
	    around .3 seconds.

	    After  bringing  the  most	active	processes into view, what
	    you'll see are the ghostly images of just the currently  run‐
	    ning tasks.

       -*-  Delete  the	 existing rcfile, or create a new symlink.  Start
	    this new version then type 'T' (a secret key, see  topic  3c.
	    TASK  Area	Commands,  Sorting)  followed  by  'W'	and  'q'.
	    Finally, restart the program with -d0 (zero delay).

	    Your display will be refreshed at three times the rate of the
	    former  top,  a 300% speed advantage.  As top climbs the TIME
	    ladder, be as patient as you can while speculating on whether
	    or not top will ever reach the top.

   6b. Bouncing Windows
       For these stupid tricks, top needs alternate-display mode.

       -*-  With 3 or 4 task displays visible, pick any window other than
	    the last and turn idle processes Off.  Depending on where you
	    applied 'i', sometimes several task displays are bouncing and
	    sometimes it's like an accordion, as top tries  his	 best  to
	    allocate space.

       -*-  Set each window's summary lines differently: one with no mem‐
	    ory; another with no states; maybe one with nothing	 at  all,
	    just the message line.  Then hold down 'a' or 'w' and watch a
	    variation on bouncing windows  --  hopping windows.

       -*-  Display all 4 windows and for each, in turn,  set  idle  pro‐
	    cesses  to	Off.   You've  just  entered the "extreme bounce"
	    zone.

   6c. The Big Bird Window
       This stupid trick also requires alternate-display mode.

       -*-  Display all 4 windows and make sure that 1:Def is  the  ´cur‐
	    rent'  window.   Then,  keep increasing window size until the
	    all the other task displays are "pushed out of the nest".

	    When they've all been displaced,  toggle  between  all  visi‐
	    ble/invisible windows.  Then ponder this:
	       is top fibbing or telling honestly your imposed truth?

7. BUGS
       Send bug reports to:
	  Albert D. Cahalan, <albert@users.sf.net>

       The  top command calculates Cpu(s) by looking at the change in CPU
       time values between samples. When you first run it, it has no pre‐
       vious  sample  to compare to, so these initial values are the per‐
       centages since boot. It means you need at least two loops  or  you
       have  to ignore summary output from the first loop.  This is prob‐
       lem for example for batch mode. There is a possible workaround  if
       you  define  the	 CPULOOP=1  environment variable. The top command
       will be run one extra hidden loop for  CPU  data	 before	 standard
       output.

8. HISTORY Former top
       The  original  top  was	written	 by  Roger Binns, based on Branko
       Lankester's <lankeste@fwi.uva.nl> ps program.

       Robert Nation <nation@rocket.sanders.lockheed.com> adapted it  for
       the proc file system.

       Helmut  Geyer  <Helmut.Geyer@iwr.uni-heidelberg.de>  added support
       for configurable fields.

       Plus many other individuals contributed over the years.

9. AUTHOR
       This entirely new and enhanced replacement was written by:
	  Jim / James C. Warner, <warnerjc@worldnet.att.net>

       With invaluable help from:
	  Albert D. Cahalan, <albert@users.sf.net>
	  Craig Small, <csmall@small.dropbear.id.au>

10. SEE ALSO
       free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1).

Linux			      September 2002			   TOP(1)
[top]

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