Manual Pages  — TOP

top – display and update information about the top cpu processes

SYNOPSIS DESCRIPTION INTERACTIVE MODE THE DISPLAY DESCRIPTION OF MEMORY Physical Memory Stats ZFS ARC Stats Swap Stats ENVIRONMENT SEE ALSO HISTORY AUTHORS BUGS

top [-abCHIijnPqSTtuvwz] [-d count] [-J jail] [-m cpu | io] [-o field] [-p pid] [-s time] [-U username] [number]

top displays the top processes on the system and periodically updates this information. If standard output is an intelligent terminal (see below) then as many processes as will fit on the terminal screen are displayed by default. Otherwise, a good number of them are shown (around 20). Raw cpu percentage is used to rank the processes. If number is given, then the top number processes will be displayed instead of the default.

top makes a distinction between terminals that support advanced capabilities and those that do not. This distinction affects the choice of defaults for certain options. In the remainder of this document, an "intelligent" terminal is one that supports cursor addressing, clear screen, and clear to end of line. Conversely, a "dumb" terminal is one that does not support such features. If the output of top is redirected to a file, it acts as if it were being run on a dumb terminal.

The options are as follows:

-a
	Display command names derived from the argv[] vector, rather than real executable name. It it useful when you want to watch applications, that puts their status information there. If the real name differs from argv[0], it will be displayed in parenthesis. Non-printable characters in the command line are encoded in C-style backslash sequences or a three digit octal sequences.
-b
	Use "batch" mode. In this mode, all input from the terminal is ignored. Interrupt characters (such as ^C and ^\) still have an effect. This is the default on a dumb terminal, or when the output is not a terminal.
-C
	Toggle CPU display mode. By default top displays the weighted CPU percentage in the WCPU column (this is the same value that ps(1) displays as CPU). Each time -C flag is passed it toggles between "raw cpu" mode and "weighted cpu" mode, showing the "CPU" or the "WCPU" column respectively.
-d count
	Show only count displays, then exit. A display is considered to be one update of the screen. The default is 1 for dumb terminals. Note that for count = 1 no information is available about the percentage of time spent by the CPU in every state.
-H
	Display each thread for a multithreaded process individually. By default a single summary line is displayed for each process.
-I
	Do not display idle processes. By default, top displays both active and idle processes.
-i
	Use "interactive" mode. In this mode, any input is immediately read for processing. See the section on "Interactive Mode" for an explanation of which keys perform what functions. After the command is processed, the screen will immediately be updated, even if the command was not understood. This mode is the default when standard output is an intelligent terminal.
-J jail
	Show only those processes owned by jail. This may be either the jid or name of the jail. Use 0 to limit to host processes. Using this option implies -j.
-j
	Display the jail(8) ID.
-m mode
	Display statistics in the specified mode. Available modes are cpu and io. Default is cpu.
-n
	Use "non-interactive" mode. This is identical to "batch" mode.
-o field
	Sort the process display area on the specified field. The field name is the name of the column as seen in the output, but in lower case: "cpu", "size", "res", "time", "pri", "threads", "total", "read", "write", "fault", "vcsw", "ivcsw", "jid", "swap", or "pid".
-P
	Display per-cpu CPU usage statistics.
-p pid
	Show only the process pid.
-q
	Renice top to -20 so that it will run faster. This can be used when the system is being very sluggish to improve the possibility of discovering the problem. This option can only be used by root.
-S
	Show system processes in the display. Normally, system processes such as the pager and the swapper are not shown. This option makes them visible.
-s time
	Set the delay between screen updates to time seconds, which may be fractional. The default delay between updates is 1 second.
-T
	Toggle displaying thread ID (tid) instead of process id (pid).
-t
	Do not display the top process itself.
-U username
	Show only those processes owned by username. This option currently only accepts usernames and will not understand uid numbers.
-u
	Do not map uid numbers to usernames. Normally, top will read as much of the file /etc/passwd as is necessary to map all the user id numbers it encounters into login names. This option disables all that, while possibly decreasing execution time. The uid numbers are displayed instead of the names.
-v
	Write version number information to stderr then exit immediately.
-w
	Display approximate swap usage for each process.
-z
	Do not display the system idle process.

Both count and number fields can be specified as "infinite", indicating that they can stretch as far as possible. This is accomplished by using any proper prefix of the keywords "infinity", "maximum", or "all". Boolean flags are toggles. A second specification of any of these options will negate the first.

Mem: 61M Active, 86M Inact, 368K Laundry, 22G Wired, 102G Free
ARC: 15G Total, 9303M MFU, 6155M MRU, 1464K Anon, 98M Header, 35M Other
     15G Compressed, 27G Uncompressed, 1.75:1 Ratio, 174M Overhead
Swap: 4096M Total, 532M Free, 13% Inuse, 80K In, 104K Out

Active	number of bytes active
Inact	number of clean bytes inactive
Laundry	number of dirty bytes queued for laundering
Wired	number of bytes wired down, including IO-level cached file data pages
Buf	number of bytes used for IO-level disk caching
Free	number of bytes free

These stats are only displayed when the ARC is in use.

Total	number of wired bytes used for the ZFS ARC
MRU	number of ARC bytes holding most recently used data
MFU	number of ARC bytes holding most frequently used data
Anon	number of ARC bytes holding in flight data
Header	number of ARC bytes holding headers
Other	miscellaneous ARC bytes
Compressed	bytes of memory used by ARC caches
Uncompressed
	bytes of data stored in ARC caches before compression
Ratio	compression ratio of data cached in the ARC

Total	total available swap usage
Free	total free swap usage
Inuse	swap usage
amp;In	bytes paged in from swap devices (last interval)
Out	bytes paged out to swap devices (last interval)

TOP	Default set of arguments to top.
LC_CTYPE	The locale to use when displaying the argv vector when -a flag is specified.

top first appeared in FreeBSD 2.2.2 .

William LeFebvre, EECS Department, Northwestern University