TOP(1) | User Commands | TOP(1) |
NAME¶
top - display Linux processesSYNOPSIS¶
top -hv|-bcHisS -d delay -n limit - u|U user -p pid -w [cols]DESCRIPTION¶
The top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of processes or threads currently being managed by the Linux kernel. The types of system summary information shown and the types, order and size of information displayed for processes are all user configurable and that configuration can be made persistent across restarts.OVERVIEW¶
Documentation¶
The remaining Table of Contents1. COMMAND-LINE Options
2. SUMMARY Display
a. UPTIME and LOAD Averages
b. TASK and CPU States
c. MEMORY Usage
3. FIELDS / Columns Display
a. DESCRIPTIONS of Fields
b. MANAGING Fields
4. INTERACTIVE Commands
a. GLOBAL Commands
b. SUMMARY AREA Commands
c. TASK AREA Commands
1. Appearance
2. Content
3. Size
4. Sorting
d. COLOR Mapping
5. ALTERNATE-DISPLAY Provisions
a. WINDOWS Overview
b. COMMANDS for Windows
c. SCROLLING a Window
d. SEARCHING in a Window
6. FILES
a. SYSTEM Configuration File
b. PERSONAL Configuration File
7. STUPID TRICKS Sampler
a. Kernel Magic
b. Bouncing Windows
c. The Big Bird Window
8. BUGS, 9. HISTORY Former top, 10. AUTHOR, 11. SEE Also
Operation¶
When operating top, the two most important keys are the help ('h' or '?') key and quit ('q') key. Alternatively, you could simply use the traditional interrupt key ('^C') when you're done.key equivalents
Up alt + \ or alt + k
Down alt + / or alt + j
Left alt + < or alt + h
Right alt + > or alt + l (lower case L)
PgUp alt + Up
PgDn alt + Down
Home alt + Left
End alt + Right
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. All are explained in detail in the sections that follow.Global-defaults
'A' - Alt display Off (full-screen)
* 'd' - Delay time 3.0 seconds
* 'H' - Threads mode Off (summarize as tasks)
'I' - Irix mode On (no, 'solaris' smp)
* 'p' - PID monitoring Off (show all processes)
* 's' - Secure mode Off (unsecured)
'B' - Bold enable On (yes, bold globally)
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)
* 'i' - Idle tasks On (show all tasks)
'R' - Reverse sort On (pids high-to-low)
* 'S' - Cumulative time Off (no, dead children)
* 'u' - User filter Off (show euid only)
* 'U' - User filter Off (show any uid)
'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:- hv | -bcHisS -d delay -n limit - u|U user | -p pid -w [cols]
- -h | -v : Help/Version
- Show library version and the usage prompt, then quit.
- -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' interactive command for
additional information.
- -d : Delay-time interval as: -d ss.tt ( secs.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.
- -H : Threads-mode operation
- Instructs top to display individual threads. Without this
command-line option a summation of all threads in each process is shown.
Later this can be changed with the 'H' interactive command.
- -i : Idle-process toggle
- Starts top with the last remembered 'i' state reversed.
When this toggle is Off, tasks that have not used any CPU since the
last update will not be displayed. For additional information regarding
this toggle see topic 4c. TASK AREA Commands, SIZE.
- -n : Number-of-iterations limit as: -n number
- Specifies the maximum number of iterations, or frames, top
should produce before ending.
- -p : Monitor-PIDs mode as: -pN1 -pN2 ... or -pN1,N2,N3 ...
- 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.
- -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 6. FILES).
- -S : Cumulative-time toggle
- Starts top with the last remembered 'S' state reversed.
When 'Cumulative time' 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.
- -u | -U : User-filter-mode as: -u | -U number or name
- Display only processes with a user id or user name matching
that given. The '-u' option matches on effective user whereas the
'-U' option matches on any user (real, effective, saved, or
filesystem).
- -w : Output-width-override as: -w [ number ]
- In 'Batch' mode, when used without an argument top will
format output using the COLUMNS= and LINES= environment variables, if set.
Otherwise, width will be fixed at the maximum 512 columns. With an
argument, output width can be decreased or increased (up to 512) but the
number of rows is considered unlimited.
2. SUMMARY Display¶
Each of the following three areas are individually controlled through one or more interactive commands. See topic 4b. SUMMARY AREA Commands for additional information regarding these provisions.2a. UPTIME and LOAD Averages¶
This portion consists of a single line containing:program or window name, depending on display mode
current time and length of time since last boot
total number of users
system load avg over the last 1, 5 and 15 minutes
2b. TASK and CPU States¶
This portion consists of a minimum of two lines. In an SMP environment, additional lines can reflect individual CPU state percentages.running; sleeping; stopped; zombie
us, user : time running un-niced user processes
sy, system : time running kernel processes
ni, nice : time running niced user processes
wa, IO-wait : time waiting for I/O completion
hi : time spent servicing hardware interrupts
si : time spent servicing software interrupts
st : time stolen from this vm by the hypervisor
2c. MEMORY Usage¶
This portion consists of two lines which may express values in kibibytes (KiB), mebibytes (MiB) or gibibytes (GiB) depending on the amount of currently installed physical memory.total, used, free, buffers
total, used, free, cached
3. FIELDS / Columns¶
3a. DESCRIPTIONS of Fields¶
Listed below are top's available process fields (columns). They are shown in alphabetical order. You may customize their position and whether or not they are displayable with the 'f' or 'F' (Fields Management) interactive commands.-
1. CGROUPS -- Control Groups - The names of the control group(s) to which a process
belongs, or '-' if not applicable for that process.
-
2. CODE -- Code Size (KiB) - The amount of physical memory devoted to executable code,
also known as the 'text resident set' size or TRS.
-
3. COMMAND -- Command Name or Command Line - 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.
[ mdrecoveryd ]
-
4. %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.
-
5. DATA -- Data + Stack Size (KiB) - The amount of physical memory devoted to other than
executable code, also known as the 'data resident set' size or DRS.
-
6. Flags -- Task Flags - This column represents the task's current scheduling flags
which are expressed in hexadecimal notation and with zeros suppressed.
These flags are officially documented in <linux/sched.h>.
-
7. GID -- Group Id - The effective group ID.
-
8. GROUP -- Group Name - The effective group name.
-
9. %MEM -- Memory Usage (RES) - A task's currently used share of available physical memory.
- 10. 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 dispatch-ability.
- 11. nDRT -- Dirty Pages Count
- The number of pages that have been modified since they were
last written to auxiliary storage. Dirty pages must be written to
auxiliary storage before the corresponding physical memory location can be
used for some other virtual page.
- 12. nMaj -- Major 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 auxiliary storage access is involved in
making that page available.
- 13. nMin -- Minor Page Fault count
- The number of minor 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 minor page fault does not involve auxiliary storage access in
making that page available.
- 14. nTH -- Number of Threads
- The number of threads associated with a process.
- 15. 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 running top may
break this weak affinity and cause more processes to change CPUs more
often (because of the extra demand for cpu time).
- 16. PGRP -- Process Group Id
- Every process is member of a unique process group which is
used for distribution of signals and by terminals to arbitrate requests
for their input and output. When a process is created (forked), it becomes
a member of the process group of its parent. By convention, this value
equals the process ID (see PID) of the first member of a process group,
called the process group leader.
- 17. PID -- Process Id
- The task's unique process ID, which periodically wraps,
though never restarting at zero. In kernel terms, it is a dispatchable
entity defined by a 'task_struct'.
- 18. PPID -- Parent Process Id
- The process ID (pid) of a task's parent.
- 19. PR -- Priority
- The scheduling priority of the task. If you see 'rt' in
this field, it means the task is running under
- 20. RES -- Resident Memory Size (KiB)
- The non-swapped physical memory a task has used.
- 21. RUID -- Real User Id
- The real user ID.
- 22. RUSER -- Real User Name
- The real user name.
- 23. 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
- 24. SHR -- Shared Memory Size (KiB)
- The amount of shared memory available to a task, not all of
which is typically resident. It simply reflects memory that could be
potentially shared with other processes.
- 25. SID -- Session Id
- A session is a collection of process groups (see PGRP),
usually established by the login shell. A newly forked process joins the
session of its creator. By convention, this value equals the process ID
(see PID) of the first member of the session, called the session leader,
which is usually the login shell.
- 26. SUID -- Saved User Id
- The saved user ID.
- 27. SUPGIDS -- Supplementary Group IDs
- The IDs of any supplementary group(s) established at login
or inherited from a task's parent. They are displayed in a comma delimited
list.
- 28. SUPGRPS -- Supplementary Group Names
- The names of any supplementary group(s) established at
login or inherited from a task's parent. They are displayed in a comma
delimited list.
- 29. SUSER -- Saved User Name
- The saved user name.
- 30. SWAP -- Swapped Size (KiB)
- The non-resident portion of a task's address space.
- 31. TGID -- Thread Group Id
- The ID of the thread group to which a task belongs. It is
the PID of the thread group leader. In kernel terms, it represents those
tasks that share an 'mm_struct'.
- 32. TIME -- CPU Time
- Total CPU time the task has used since it started. When
'Cumulative mode' is On, each process is listed with the cpu time
that it and its dead children have used. You toggle 'Cumulative mode' with
'S', which is both a command-line option and an interactive command. See
the 'S' interactive command for additional information regarding this
mode.
- 33. TIME+ -- CPU Time, hundredths
- The same as 'TIME', but reflecting more granularity through
hundredths of a second.
- 34. TPGID -- Tty Process Group Id
- The process group ID of the foreground process for the
connected tty, or -1 if a process is not connected to a terminal. By
convention, this value equals the process ID (see PID) of the the process
group leader (see PGRP).
- 35. 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.
- 36. UID -- User Id
- The effective user ID of the task's owner.
- 37. USER -- User Name
- The effective user name of the task's owner.
- 38. VIRT -- Virtual Memory Size (KiB)
- 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 and pages that have been mapped but not used.
- 39. WCHAN -- Sleeping in Function
- Depending on the availability of the kernel link map
('System.map'), this field will show the name or the address of the kernel
function in which the task is currently sleeping. Running tasks will
display a dash ('-') in this column.
3b. MANAGING Fields¶
After pressing the interactive command 'f' or 'F' (Fields Management) you will be presented with a screen showing: 1) the ´current´ window name; 2) the designated sort field; 3) all fields in their current order along with descriptions. Entries marked with an asterisk are the currently displayed fields, screen width permitting.- o
- As the on screen instructions indicate, you navigate among
the fields with the Up and Down arrow keys. The PgUp, PgDn,
Home and End keys can also be used to quickly reach the first or last
available field.
- o
- The Right arrow key selects a field for
repositioning and the Left arrow key or the <Enter>
key commits that field's placement.
- o
- The 'd' key or the <Space> bar toggles
a field's display status, and thus the presence or absence of the
asterisk.
- o
- The 's' key designates a field as the sort field.
See topic 4c. TASK AREA Commands, SORTING for additional information
regarding your selection of a sort field.
- o
- The 'a' and 'w' keys can be used to cycle through all available windows and the ' q' or <Esc> keys exit Fields Management.
4. 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.4a. Global-Commands
<Ent/Sp> ?, =, A, B, d, g, h, H, I, k, q, r, s, W, Z
4b. Summary-Area-Commands
C, l, t, 1, m
4c. Task-Area-Commands
Appearance: b, x, y, z
Content: c, f, F, S, u, U, V
Size: #, i, n
Sorting: <, >, f, F, R
4d. Color-Mapping
<Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
5b. Commands-for-Windows
-, _, =, +, A, a, g, G, w
5c. Scrolling-a-Window
C, Up, Dn, Left, Right, PgUp, PgDn, Home, End
5d. Searching-in-a-Window
L, &
4a. 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'.- <Enter> or <Space> :Refresh-Display
- These commands awaken top and following receipt of any
input the entire display will be repainted. They also force an update of
any hotplugged cpu or physical memory changes.
- ´?´ | ´h´ :Help
- There are two help levels available. The first will provide
a reminder of all the basic interactive commands. If top is
secured, that screen will be abbreviated.
- ´=´ :Exit-Task-Limits
- Removes restrictions on which tasks are shown. This command
will reverse any 'i' (idle tasks) and 'n' (max tasks) commands that might
be active. It also provides for an 'exit' from pid monitoring and
user filtering. See the '-p' command-line option for a discussion of PID
monitoring and the 'U' or 'u' interactive commands regarding user
filtering.
- ´A´ :Alternate-Display-Mode toggle
- This command will switch between full-screen mode and
alternate-display mode. See topic 5. ALTERNATE-DISPLAY Provisions and the
'g' interactive command for insight into ´current´ 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.
- * ´d´ | ´s´ :Change-Delay-Time-interval
- You will be prompted to enter the delay time, in seconds,
between display updates.
- ´g´ :Choose-Another-Window/Field-Group
- You will be prompted to enter a number between 1 and 4
designating the field group which should be made the ´current´
window. You will soon grow comfortable with these 4 windows, especially
after experimenting with alternate-display mode.
- ´H´ :Threads-mode toggle
- When this toggle is On, individual threads will be
displayed for all processes in all visible task windows. Otherwise, top
displays a summation of all threads in each process.
- ´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 told the new state of this toggle.
- * ´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.
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 command 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 windows.
For details regarding this interactive command see topic 4d. 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.
4b. 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.- ´l´ :Load-Average/Uptime toggle
- This is also the line containing the program name (possibly
an alias) when operating in full-screen mode or the ´current´
window name when operating in alternate-display mode.
- ´t´ :Task/Cpu-States toggle
- 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´ :Single/Separate-Cpu-States toggle
- This command affects how the 't' command's Cpu States
portion is shown. Although this toggle exists primarily to serve
massively-parallel SMP machines, it is not restricted to solely SMP
environments.
- ´m´ :Memory/Swap-Usage toggle
- This command affects the two summary area lines dealing
with physical and virtual memory.
4c. TASK AREA Commands¶
The task area interactive commands are always available in full-screen mode.- APPEARANCE of task window
- The following commands will also be influenced by the state
of the global 'B' (bold enable) 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. If you
forget which field is being sorted this command can serve as a quick
visual reminder, providing the sort field is being displayed. The sort
field might not be visible because:
1) there is insufficient Screen Width
2) the 'f' interactive command turned it Off
- ´y´ :Row-Highlight toggle
- Changes highlighting for "running" tasks. For
additional insight into this task state, see topic 3a. DESCRIPTIONS of
Fields, the 'S' field (Process Status).
- ´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.
- ´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´ | ´F´ :Fields-Management
- These keys display a separate screen where you can change
which fields are displayed, their order and also designate the sort field.
For additional information on these interactive commands see topic 3b.
MANAGING Fields.
- ´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.
- ´u' | 'U' :Show-Specific-User-Only
- You will be prompted for the uid or name of
the user to display. The '-u' option matches on effective user
whereas the '-U' option matches on any user (real, effective,
saved, or filesystem).
- ´V' :Forest-View-Mode toggle
- In this mode, processes are reordered according to their
parents and the layout of the COMMAND column resembles that of a tree. In
forest view mode it is still possible to toggle between program name and
commamd line (see the 'c' interactive command) or between processes and
threads (see the 'H' interactive command).
- ´i´ :Idle-Process toggle
- Displays all tasks or just active tasks. When this toggle
is Off, tasks that have not used any CPU since the last update will
not be displayed. However, due to the granularity of the %CPU and TIME+
fields, some processes may still be displayed that appear to have
used no CPU.
- ´n´ | ´#´ :Set-Maximum-Tasks
- You will be prompted to enter the number of tasks to
display. The lessor of your number and available screen rows will be used.
- 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
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´ | ´F´ :Fields-Management
- These keys display a separate screen where you can change
which field is used as the sort column, among other functions. This 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.
4d. 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.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
5. ALTERNATE-DISPLAY Provisions¶
5a. 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.
- Current Window:
- The ´current´ window is the window associated
with the summary 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.
5b. COMMANDS for Windows¶
- ´-´ | ´_´ :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'
interactive command. It will also reflect any other task area
options/toggles you've applied yielding zero or more tasks.
- * ´=´ | ´+´ :Equalize-(re-balance)-Window(s)
- The '=' key forces the ´current´ window's task
display to be visible. It also reverses any 'i' (idle tasks), 'n' (max
tasks) and 'u'/'U' (user filter) commands that might be active. Also, if
the window had been scrolled, it will be reset with this command. See
topic 5c. SCROLLING a Window for additional information regarding vertical
and horizontal scrolling.
- * ´A´ :Alternate-Display-Mode toggle
- This command will switch between full-screen mode and
alternate-display mode.
- * ´a´ | ´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.
- * ´g´ :Choose-Another-Window/Field-Group
- You will be prompted to enter a number between 1 and 4
designating the field group which should be made the ´current´
window.
- ´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 with color mapping
and fields management
5c. SCROLLING a Window¶
Typically a task window is a partial view into a systems's total tasks/threads which shows only some of the available fields/columns. With these scrolling keys, you can move that view vertically or horizontally to reveal any desired task or column.- Up,PgUp :Scroll-Tasks
- Move the view up toward the first task row, until the first
task is displayed at the top of the ´current´ window. The
Up arrow key moves a single line while PgUp scrolls the
entire window.
- Down,PgDn :Scroll-Tasks
- Move the view down toward the last task row, until the last
task is the only task displayed at the top of the ´current´
window. The Down arrow key moves a single line while PgDn
scrolls the entire window.
- Left,Right :Scroll-Columns
- Move the view of displayable fields horizontally one column
at a time.
- Home :Jump-to-Home-Position
- Reposition the display to the un-scrolled coordinates.
- End :Jump-to-End-Position
- Reposition the display so that the rightmost column
reflects the last displayable field and the bottom task row represents the
last task.
- Toggle an informational message which is displayed whenever the message
- line is not otherwise being used.
" scroll coordinates: y = n/n (tasks), x = n/n (fields)"
- y = n/n (tasks)
- The first n represents the topmost visible task and
is controlled by scrolling keys. The second n is updated
automatically to reflect total tasks.
- x = n/n (fields)
- The first n represents the leftmost displayed column and is controlled by scrolling keys. The second n is the total number of displayable fields and is established with the ' f' interactive command.
5d. SEARCHING in a Window¶
You can use these interactive commands to locate a task row containing a particular value.- You will be prompted for the case-sensitive string to locate starting from
- the current window coordinates. There are no restrictions
on search string content.
- Assuming a search string has been established, top will attempt to locate
- the next occurrence.
- a. Which fields are displayable from the total available,
- see topic 3b. MANAGING Fields.
- b. Scrolling a window vertically and/or horizontally,
- see topic 5c. SCROLLING a Window.
- c. The state of the command/command-line toggle,
- see the 'c' interactive command.
- d. The stability of the chosen sort column,
- for example PID is good but %CPU bad.
6. FILES¶
6a. 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 running. 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
s # line 1: 'secure' mode switch
5.0 # line 2: 'delay' interval in seconds
6b. 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.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
7. 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.7a. Kernel Magic¶
For these stupid tricks, top needs full-screen mode.- o
- 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.
. provide a scheduling boost and tiny delay via:
nice -n -10 top -d.09
. keep sorted column highlighting Off so as 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
- o
- Under an xterm using 'white-on-black' colors, on top's
Color Mapping screen set the 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.
- o
- Delete the existing rcfile, or create a new symlink. Start
this new version then type 'T' (a secret key, see topic 4c. Task Area
Commands, SORTING) followed by 'W' and 'q'. Finally, restart the program
with -d0 (zero delay).
7b. Bouncing Windows¶
For these stupid tricks, top needs alternate-display mode.- o
- With 3 or 4 task displays visible, pick any window other
than the last and turn idle processes Off using the 'i' command
toggle. 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.
- o
- Set each window's summary lines differently: one with no
memory ('m'); another with no states ('t'); 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.
- o
- Display all 4 windows and for each, in turn, set idle
processes to Off using the 'i' command toggle. You've just entered
the "extreme bounce" zone.
7c. The Big Bird Window¶
This stupid trick also requires alternate-display mode.- o
- Display all 4 windows and make sure that 1:Def is the
´current´ window. Then, keep increasing window size with the 'n'
interactive command until all the other task displays are "pushed out
of the nest".
is top fibbing or telling honestly your imposed truth?
8. BUGS¶
To report bugs, follow the instructions at:http://www.debian.org/Bugs/Reporting
9. HISTORY Former top¶
The original top was written by Roger Binns, based on Branko Lankester's <lankeste@fwi.uva.nl> ps program.10. AUTHOR¶
This entirely new and enhanced replacement was written by:Jim Warner, <james.warner@comcast.net>
Craig Small, <csmall@enc.com.au>
Albert Cahalan, <albert@users.sf.net>
11. SEE Also¶
free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1).April 2011 | procps-ng |