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

NAME
       top - display top CPU processes

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

DESCRIPTION
       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 bet-
       ter  configured than the	standard top from the procps suite.  Most fea-
       tures can either	be selected by an interactive command or by specifying
       the  feature in the personal or system-wide configuration file. See be-
       low for more information.

COMMAND-LINE OPTIONS
       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	inter-
	    actively nor can it	be put into the	configuration 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  in-
	    teractive 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 interac-
	    tive command i below.

       C    display total CPU states instead of	individual CPUs.  This	option
	    only affects SMP systems.

       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  in-
	    put.  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.

FIELD DESCRIPTIONS
       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.

       uptime
	    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 min-
	    utes.  This	line is	just like the output of	uptime(1).  The	uptime
	    display may	be toggled by the interactive l	command.

       processes
	    The	 total number of processes running at the time of the last up-
	    date.  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	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 interac-
	    tive 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  pri-
	    ority.

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

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

       DSIZE
	    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 kilo-
	    bytes, is shown here. For ELF processes  used  library  pages  are
	    counted here, for a.out processes not.

       SHARE
	    The	amount of shared memory	used by	the task is shown in this col-
	    umn.

       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 zom-
	    bies, 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
	    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, ex-
	    pressed as a percentage of total CPU time per processor.

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

       COMMAND
	    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.

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

       space
	    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 sig-
	    nal, as with kill(1), is 15, SIGTERM.  This	command	is not	avail-
	    able 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 sys-
	    tems.

       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  mea-
	    surement.  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 sepa-
	    rate 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
       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 con-
       tents. 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
       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 con-
       tains 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	recom-
       mended to select	fields and order in a running top process and to  save
       this  using  the	W interactive command.	The second line	is more	inter-
       esting (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
       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 be-
       tween 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	expen-
       sive,  possibly	prohibitively  so.  In any case, that would make top's
       behavior	incompatible with ps.

FILES
       /etc/toprc The global configuration file.  ~/.toprc The	personal  con-
       figuration file.

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

BUGS
       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

AUTHOR
       top  was	originally written by Roger Binns, based on Branko Lankester's
       <lankeste@fwi.uva.nl>	ps    program.	    Robert     Nation	  <na-
       tion@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	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 Services.

       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)

NAME | SYNOPSIS | DESCRIPTION | COMMAND-LINE OPTIONS | FIELD DESCRIPTIONS | INTERACTIVE COMMANDS | The Field and Order Screens | Configuration Files | NOTES | FILES | SEE ALSO | BUGS | AUTHOR

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