1TOP(1) Linux User's Manual TOP(1)
2
6 top - display Linux tasks
7
11 ⟨⟩
12 -hv | -bcHisS -d delay -n iterations -p pid [, pid ...]
13 The traditional switches '-' and whitespace are optional.
15
19 The .ie 0 . br
20 program provides a dynamic real-time view of a running system.
21 It can display system summary information as well as a list of
22 tasks currently being managed by the Linux kernel. The types of
23 system summary information shown and the types, order and size of
24 information displayed for tasks are all user configurable and that
25 configuration can be made persistent across restarts.
26 The program provides a limited interactive interface for process
28 manipulation as well as a much more extensive interface for per‐
29 sonal configuration -- encompassing every aspect of its opera‐
30 tion. And while .ie 0 . br
31 is referred to throughout this document, you are free to name the
32 program anything you wish. That new name, possibly an alias, will
33 then be reflected on top's display and used when reading and writ‐
34 ing a configuration file.
35
39 Documentation
40 The remaining Table of Contents
41 1. COMMAND-LINE Options
42 2. FIELDS / Columns
43 a. DESCRIPTIONS of Fields
44 b. SELECTING and ORDERING Columns
45 3. INTERACTIVE Commands
46 a. GLOBAL Commands
47 b. SUMMARY Area Commands
48 c. TASK Area Commands
49 d. COLOR Mapping
50 4. ALTERNATE-DISPLAY Mode
51 a. WINDOWS Overview
52 b. COMMANDS for Windows
53 5. FILES
54 a. SYSTEM Configuration File
55 b. PERSONAL Configuration File
56 6. STUPID TRICKS Sampler
57 a. Kernel Magic
58 b. Bouncing Windows
59 c. The Big Bird Window
60 7. BUGS, 8. HISTORY Former top, 9. AUTHOR, 10. SEE ALSO
61 Operation
64 When operating top, the two most important keys are help ('h' or
65 '?') and quit ('q') key. Alternatively, you could simply use the
66 traditional interrupt key ('^C') when you're done.
67 When you start top for the first time, you'll be presented with
69 the traditional screen elements: 1) Summary Area; 2) Mes‐
70 sage/Prompt Line; 3) Columns Header; 4) Task Area. There will,
71 however, be some differences when compared to the former top.
72 Highlighting
75 Summary_Area: There is no highlighting for load/uptime and only
76 values are highlighted for other elements.
77 Task_Area: Tasks running (or ready to run) will be highlighted,
79 and bold is only one way of emphasizing such processes.
80 Content/Labels
83 Summary_Area: The program name is shown, perhaps a symlink or
84 alias. The Cpu(s) state label hints at other possibilities.
85 The memory stats use a lower case 'k'.
86 Columns_Header: Will show a new field and some changed labels.
88 More new fields will be found as you customize your top.
89 Note: the width of top's display will be limited to 512 positions.
92 Displaying all fields requires a minimum of 160 characters. The
93 remaining width could be used for the 'Command' column.
94 Startup Defaults
97 The following startup defaults assume no configuration file, thus
98 no user customizations. Even so, items shown with an asterisk
99 ('*') could be overridden through the command-line.
100 Global_defaults
102 'A' - Alt display Off (full-screen)
103 * 'd' - Delay time 3.0 seconds
104 'I' - Irix mode On (no, 'solaris' smp)
105 * 'p' - PID monitoring Off
106 * 's' - Secure mode Off (unsecured)
107 'B' - Bold disable Off
108 Summary_Area_defaults
109 'l' - Load Avg/Uptime On (thus program name)
110 't' - Task/Cpu states On (1+1 lines, see '1')
111 'm' - Mem/Swap usage On (2 lines worth)
112 '1' - Single Cpu On (thus 1 line if smp)
113 Task_Area_defaults
114 'b' - Bold hilite On (not 'reverse')
115 * 'c' - Command line Off (name, not cmdline)
116 * 'H' - Threads Off (show all threads)
117 * 'i' - Idle tasks On (show all tasks)
118 'R' - Reverse sort On (pids high-to-low)
119 * 'S' - Cumulative time Off (no, dead children)
120 'x' - Column hilite Off (no, sort field)
121 'y' - Row hilite On (yes, running tasks)
122 'z' - color/mono Off (no, colors)
123
127 The command-line syntax for top consists of:
128 -hv | -bcHisS -d delay -n iterations -p pid [,pid...]
130 The typically mandatory switches ('-') and even whitespace are
132 completely optional.
133 -b : Batch mode operation
136 Starts top in 'Batch mode', which could be useful for sending
137 output from top to other programs or to a file. In this
138 mode, top will not accept input and runs until the iterations
139 limit you've set with the '-n' command-line option or until
140 killed.
141 -c : Command line/Program name toggle
144 Starts top with the last remembered 'c' state reversed.
145 Thus, if top was displaying command lines, now that field
146 will show program names, and visa versa. See the 'c' inter‐
147 active command for additional information.
148 -d : Delay time interval as: -d ss.tt (seconds.tenths)
151 Specifies the delay between screen updates, and overrides the
152 corresponding value in one's personal configuration file or
153 the startup default. Later this can be changed with the 'd'
154 or 's' interactive commands.
155 Fractional seconds are honored, but a negative number is not
157 allowed. In all cases, however, such changes are prohibited
158 if top is running in 'Secure mode', except for root (unless
159 the 's' command-line option was used). For additional infor‐
160 mation on 'Secure mode' see topic 5a. SYSTEM Configuration
161 File.
162 -h : Help
166 Show library version and the usage prompt, then quit.
167 -H : Threads toggle
170 Starts top with the last remembered 'H' state reversed. When
171 this toggle is On, all individual threads will be displayed.
172 Otherwise, top displays a summation of all threads in a
173 process.
174 -i : Idle Processes toggle
177 Starts top with the last remembered 'i' state reversed. When
178 this toggle is Off, tasks that are idled or zombied will not
179 be displayed.
180 -n : Number of iterations limit as: -n number
183 Specifies the maximum number of iterations, or frames, top
184 should produce before ending.
185 -u : Monitor by user as: -u somebody
188 Monitor only processes with an effective UID or user name
189 matching that given.
190 -U : Monitor by user as: -U somebody
193 Monitor only processes with a UID or user name matching that
194 given. This matches real, effective, saved, and filesystem
195 UIDs.
196 -p : Monitor PIDs as: -pN1 -pN2 ... or -pN1, N2 [,...]
199 Monitor only processes with specified process IDs. This
200 option can be given up to 20 times, or you can provide a
201 comma delimited list with up to 20 pids. Co-mingling both
202 approaches is permitted.
203 This is a command-line option only. And should you wish to
205 return to normal operation, it is not necessary to quit and
206 and restart top -- just issue the '=' interactive command.
207 -s : Secure mode operation
210 Starts top with secure mode forced, even for root. This mode
211 is far better controlled through the system configuration
212 file (see topic 5. FILES).
213 -S : Cumulative time mode toggle
216 Starts top with the last remembered 'S' state reversed. When
217 'Cumulative mode' is On, each process is listed with the cpu
218 time that it and its dead children have used. See the 'S'
219 interactive command for additional information regarding this
220 mode.
221 -v : Version
224 Show library version and the usage prompt, then quit.
225
229 2a. DESCRIPTIONS of Fields
230 Listed below are top's available fields. They are always associ‐
231 ated with the letter shown, regardless of the position you may
232 have established for them with the 'o' (Order fields) interactive
233 command.
234 Any field is selectable as the sort field, and you control whether
236 they are sorted high-to-low or low-to-high. For additional infor‐
237 mation on sort provisions see topic 3c. TASK Area Commands.
238 a: PID -- Process Id
241 The task's unique process ID, which periodically wraps, though
242 never restarting at zero.
243 b: PPID -- Parent Process Pid
246 The process ID of a task's parent.
247 c: RUSER -- Real User Name
250 The real user name of the task's owner.
251 d: UID -- User Id
254 The effective user ID of the task's owner.
255 e: USER -- User Name
258 The effective user name of the task's owner.
259 f: GROUP -- Group Name
262 The effective group name of the task's owner.
263 g: TTY -- Controlling Tty
266 The name of the controlling terminal. This is usually the
267 device (serial port, pty, etc.) from which the process was
268 started, and which it uses for input or output. However, a
269 task need not be associated with a terminal, in which case
270 you'll see '?' displayed.
271 h: PR -- Priority
274 The priority of the task.
275 i: NI -- Nice value
278 The nice value of the task. A negative nice value means higher
279 priority, whereas a positive nice value means lower priority.
280 Zero in this field simply means priority will not be adjusted
281 in determining a task's dispatchability.
282 j: P -- Last used CPU (SMP)
285 A number representing the last used processor. In a true SMP
286 environment this will likely change frequently since the kernel
287 intentionally uses weak affinity. Also, the very act of run‐
288 ning top may break this weak affinity and cause more processes
289 to change CPUs more often (because of the extra demand for cpu
290 time).
291 k: %CPU -- CPU usage
294 The task's share of the elapsed CPU time since the last screen
295 update, expressed as a percentage of total CPU time. In a true
296 SMP environment, if 'Irix mode' is Off, top will operate in
297 'Solaris mode' where a task's cpu usage will be divided by the
298 total number of CPUs. You toggle 'Irix/Solaris' modes with the
299 'I' interactive command.
300 l: TIME -- CPU Time
303 Total CPU time the task has used since it started. When 'Cumu‐
304 lative mode' is On, each process is listed with the cpu time
305 that it and its dead children has used. You toggle 'Cumulative
306 mode' with 'S', which is a command-line option and an interac‐
307 tive command. See the 'S' interactive command for additional
308 information regarding this mode.
309 m: TIME+ -- CPU Time, hundredths
312 The same as 'TIME', but reflecting more granularity through
313 hundredths of a second.
314 n: %MEM -- Memory usage (RES)
317 A task's currently used share of available physical memory.
318 o: VIRT -- Virtual Image (kb)
321 The total amount of virtual memory used by the task. It
322 includes all code, data and shared libraries plus pages that
323 have been swapped out. (Note: you can define the STATSIZE=1
324 environment variable and the VIRT will be calculated from the
325 /proc/#/state VmSize field.)
326 VIRT = SWAP + RES.
328 p: SWAP -- Swapped size (kb)
331 The swapped out portion of a task's total virtual memory image.
332 q: RES -- Resident size (kb)
335 The non-swapped physical memory a task has used.
336 RES = CODE + DATA.
338 r: CODE -- Code size (kb)
341 The amount of physical memory devoted to executable code, also
342 known as the 'text resident set' size or TRS.
343 s: DATA -- Data+Stack size (kb)
346 The amount of physical memory devoted to other than executable
347 code, also known as the 'data resident set' size or DRS.
348 t: SHR -- Shared Mem size (kb)
351 The amount of shared memory used by a task. It simply reflects
352 memory that could be potentially shared with other processes.
353 u: nFLT -- Page Fault count
356 The number of major page faults that have occurred for a task.
357 A page fault occurs when a process attempts to read from or
358 write to a virtual page that is not currently present in its
359 address space. A major page fault is when disk access is
360 involved in making that page available.
361 v: nDRT -- Dirty Pages count
364 The number of pages that have been modified since they were
365 last written to disk. Dirty pages must be written to disk
366 before the corresponding physical memory location can be used
367 for some other virtual page.
368 w: S -- Process Status
371 The status of the task which can be one of:
372 'D' = uninterruptible sleep
373 'R' = running
374 'S' = sleeping
375 'T' = traced or stopped
376 'Z' = zombie
377 Tasks shown as running should be more properly thought of as
379 'ready to run' -- their task_struct is simply represented on
380 the Linux run-queue. Even without a true SMP machine, you may
381 see numerous tasks in this state depending on top's delay
382 interval and nice value.
383 x: Command -- Command line or Program name
386 Display the command line used to start a task or the name of
387 the associated program. You toggle between command line and
388 name with 'c', which is both a command-line option and an
389 interactive command.
390 When you've chosen to display command lines, processes without
392 a command line (like kernel threads) will be shown with only
393 the program name in parentheses, as in this example:
394 ( mdrecoveryd )
395 Either form of display is subject to potential truncation if
397 it's too long to fit in this field's current width. That width
398 depends upon other fields selected, their order and the current
399 screen width.
400 Note: The 'Command' field/column is unique, in that it is not
402 fixed-width. When displayed, this column will be allocated all
403 remaining screen width (up to the maximum 512 characters) to
404 provide for the potential growth of program names into command
405 lines.
406 y: WCHAN -- Sleeping in Function
409 Depending on the availability of the kernel link map ('Sys‐
410 tem.map'), this field will show the name or the address of the
411 kernel function in which the task is currently sleeping. Run‐
412 ning tasks will display a dash ('-') in this column.
413 Note: By displaying this field, top's own working set will be
415 increased by over 700Kb. Your only means of reducing that
416 overhead will be to stop and restart top.
417 z: Flags -- Task Flags
420 This column represents the task's current scheduling flags
421 which are expressed in hexadecimal notation and with zeros sup‐
422 pressed. These flags are officially documented in
423 <linux/sched.h>. Less formal documentation can also be found
424 on the 'Fields select' and 'Order fields' screens.
425 2b. SELECTING and ORDERING Columns
428 After pressing the interactive commands 'f' (Fields select) or ´o'
429 (Order fields) you will be shown a screen containing the current
430 fields string followed by names and descriptions for all fields.
431 Here is a sample fields string from one of top's four win‐
433 dows/field groups and an explanation of the conventions used:
434 - Sample fields string:
436 ANOPQRSTUVXbcdefgjlmyzWHIK
437 - The order of displayed fields corresponds to the order of the
439 letters in that string.
440 - If the letter is upper case the corresponding field itself will
442 then be shown as part of the task display (screen width permit‐
443 ting). This will also be indicated by a leading asterisk
444 ('*'), as in this excerpt:
445 ...
446 * K: %CPU = CPU usage
447 l: TIME = CPU Time
448 m: TIME+ = CPU Time, hundredths
449 * N: %MEM = Memory usage (RES)
450 * O: VIRT = Virtual Image (kb)
451 ...
452 Fields select screen -- the 'f' interactive command
455 You toggle the display of a field by simply pressing the corre‐
456 sponding letter.
457 Order fields screen -- the 'o' interactive command
460 You move a field to the left by pressing the corresponding
461 upper case letter and to the right with the lower case letter.
462
466 Listed below is a brief index of commands within categories. Some
467 commands appear more than once -- their meaning or scope may
468 vary depending on the context in which they are issued.
469 3a. GLOBAL_Commands
471 <Ret/Sp> ?, =, A, B, d, G, h, I, k, q, r, s, W, Z
472 3b. SUMMARY_Area_Commands
473 l, m, t, 1
474 3c. TASK_Area_Commands
475 Appearance: b, x, y, z
476 Content: c, f, H, o, S, u
477 Size: #, i, n
478 Sorting: <, >, F, O, R
479 3d. COLOR_Mapping
480 <Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
481 4b. COMMANDS_for_Windows
482 -, _, =, +, A, a, G, g, w
483 3a. GLOBAL Commands
486 The global interactive commands are always available in both
487 full-screen mode and alternate-display mode. However, some of
488 these interactive commands are not available when running in
489 'Secure mode'.
490 If you wish to know in advance whether or not your top has been
492 secured, simply ask for help and view the system summary on the
493 second line.
494 <Enter> or <Space> :Refresh_Display
497 These commands do nothing, they are simply ignored. How‐
498 ever, they will awaken top and following receipt of any
499 input the entire display will be repainted.
500 Use either of these keys if you have a large delay interval
502 and wish to see current status,
503 ´?´ or ´h´ :Help
506 There are two help levels available. The first will pro‐
507 vide a reminder of all the basic interactive commands. If
508 top is secured, that screen will be abbreviated.
509 Typing 'h' or '?' on that help screen will take you to help
511 for those interactive commands applicable to alternate-dis‐
512 play mode.
513 ´=´ :Exit_Task_Limits
516 Removes restrictions on which tasks are shown. This com‐
517 mand will reverse any 'i' (idle tasks) and 'n' (max tasks)
518 commands that might be active. It also provides for an
519 'exit' from PID monitoring. See the '-p' command-line
520 option for a discussion of PID monitoring.
521 When operating in alternate-display mode this command has a
523 slightly broader meaning.
524 ´A´ :Alternate_Display_Mode_toggle
527 This command will switch between full-screen mode and
528 alternate-display mode. See topic 4. ALTERNATE-DISPLAY
529 Mode and the 'G' interactive command for insight into ´cur‐
530 rent' windows and field groups.
531 ´B´ :Bold_Disable/Enable_toggle
534 This command will influence use of the 'bold' terminfo
535 capability and alters both the summary area and task area
536 for the ´current' window. While it is intended primarily
537 for use with dumb terminals, it can be applied anytime.
538 Note: When this toggle is On and top is operating in mono‐
540 chrome mode, the entire display will appear as normal text.
541 Thus, unless the 'x' and/or 'y' toggles are using reverse
542 for emphasis, there will be no visual confirmation that
543 they are even on.
544 * ´d´ or ´s´ :Change_Delay_Time_interval
547 You will be prompted to enter the delay time, in seconds,
548 between display updates.
549 Fractional seconds are honored, but a negative number is
551 not allowed. Entering 0 causes (nearly) continuous
552 updates, with an unsatisfactory display as the system and
553 tty driver try to keep up with top's demands. The delay
554 value is inversely proportional to system loading, so set
555 it with care.
556 If at any time you wish to know the current delay time,
558 simply ask for help and view the system summary on the sec‐
559 ond line.
560 ´G´ :Choose_Another_Window/Field_Group
563 You will be prompted to enter a number between 1 and 4 des‐
564 ignating the window/field group which should be made the
565 ´current' window. You will soon grow comfortable with
566 these 4 windows, especially after experimenting with alter‐
567 nate-display mode.
568 ´I´ :Irix/Solaris_Mode_toggle
571 When operating in 'Solaris mode' ('I' toggled Off), a
572 task's cpu usage will be divided by the total number of
573 CPUs. After issuing this command, you'll be informed of
574 the new state of this toggle.
575 ´u´ :select a user
578 You will be prompted for a UID or username. Only processes
579 belonging to the selected user will be displayed. This
580 option matches on the effective UID.
581 ´U´ :select a user
584 You will be prompted for a UID or username. Only processes
585 belonging to the selected user will be displayed. This
586 option matches on the real, effective, saved, and filesys‐
587 tem UID.
588 * ´k´ :Kill_a_task
591 You will be prompted for a PID and then the signal to send.
592 The default signal, as reflected in the prompt, is SIGTERM.
593 However, you can send any signal, via number or name.
594 If you wish to abort the kill process, do one of the fol‐
596 lowing depending on your progress:
597 1) at the pid prompt, just press <Enter>
598 2) at the signal prompt, type 0
599 ´q´ :Quit
602 * ´r´ :Renice_a_Task
605 You will be prompted for a PID and then the value to nice
606 it to. Entering a positive value will cause a process to
607 lose priority. Conversely, a negative value will cause a
608 process to be viewed more favorably by the kernel.
609 ´W´ :Write_the_Configuration_File
612 This will save all of your options and toggles plus the
613 current display mode and delay time. By issuing this com‐
614 mand just before quitting top, you will be able restart
615 later in exactly that same state.
616 ´Z´ :Change_Color_Mapping
619 This key will take you to a separate screen where you can
620 change the colors for the ´current' window, or for all win‐
621 dows. For details regarding this interactive command see
622 topic 3d. COLOR Mapping.
623 * The commands shown with an asterisk ('*') are not available in
626 'Secure mode', nor will they be shown on the level-1 help
627 screen.
628 3b. SUMMARY Area Commands
631 The summary area interactive commands are always available in both
632 full-screen mode and alternate-display mode. They affect the
633 beginning lines of your display and will determine the position of
634 messages and prompts.
635 These commands always impact just the ´current' window/field
637 group. See topic 4. ALTERNATE-DISPLAY Mode and the 'G' interac‐
638 tive command for insight into ´current' windows and field groups.
639 ´l´ :Toggle_Load_Average/Uptime -- On/Off
642 This is also the line containing the program name (possibly
643 an alias) when operating in full-screen mode or the ´cur‐
644 rent' window name when operating in alternate-display mode.
645 ´m´ :Toggle_Memory/Swap_Usage -- On/Off
648 This command affects two summary area lines.
649 ´t´ :Toggle_Task/Cpu_States -- On/Off
652 This command affects from 2 to many summary area lines,
653 depending on the state of the '1' toggle and whether or not
654 top is running under true SMP.
655 ´1´ :Toggle_Single/Separate_Cpu_States -- On/Off
658 This command affects how the 't' command's Cpu States por‐
659 tion is shown. Although this toggle exists primarily to
660 serve massively-parallel SMP machines, it is not restricted
661 to solely SMP environments.
662 When you see 'Cpu(s):' in the summary area, the '1' toggle
664 is On and all cpu information is gathered in a single line.
665 Otherwise, each cpu is displayed separately as: 'Cpu0,
666 Cpu1, ...'
667 Note: If the entire summary area has been toggled Off for any win‐
670 dow, you would be left with just the message line. In that way,
671 you will have maximized available task rows but (temporarily) sac‐
672 rificed the program name in full-screen mode or the ´current' win‐
673 dow name when in alternate-display mode.
674 3c. TASK Area Commands
677 The task area interactive commands are always available in
678 full-screen mode.
679 The task area interactive commands are never available in alter‐
681 nate-display mode if the ´current' window's task display has been
682 toggled Off (see topic 4. ALTERNATE-DISPLAY Mode).
683 APPEARANCE of task window
686 The following commands will also be influenced by the state of
687 the global 'B' (bold disable) toggle.
688 ´b´ :Bold/Reverse_toggle
691 This command will impact how the 'x' and 'y' toggles are
692 displayed. Further, it will only be available when at
693 least one of those toggles is On.
694 ´x´ :Column_Highlight_toggle
697 Changes highlighting for the current sort field. You prob‐
698 ably don't need a constant visual reminder of the sort
699 field and top hopes that you always run with 'column high‐
700 light' Off, due to the cost in path-length.
701 If you forget which field is being sorted this command can
703 serve as a quick visual reminder.
704 ´y´ :Row_Highlight_toggle
707 Changes highlighting for "running" tasks. For additional
708 insight into this task state, see topic 2a. DESCRIPTIONS of
709 Fields, Process Status.
710 Use of this provision provides important insight into your
712 system's health. The only costs will be a few additional
713 tty escape sequences.
714 ´z´ :Color/Monochrome_toggle
717 Switches the ´current' window between your last used color
718 scheme and the older form of black-on-white or white-on-
719 black. This command will alter both the summary area and
720 task area but does not affect the state of the 'x', 'y' or
721 'b' toggles.
722 CONTENT of task window
725 ´c´ :Command_Line/Program_Name_toggle
726 This command will be honored whether or not the 'Command'
727 column is currently visible. Later, should that field come
728 into view, the change you applied will be seen.
729 ´f´ and ´o´ :Fields_select or Order_fields
731 These keys display separate screens where you can change
732 which fields are displayed and their order. For additional
733 information on these interactive commands see topic 2b.
734 SELECTING and ORDERING Columns.
735 ´H´ :Threads_toggle
737 When this toggle is On, all individual threads will be dis‐
738 played. Otherwise, top displays a summation of all threads
739 in a process.
740 ´S´ :Cumulative_Time_Mode_toggle
742 When 'Cumulative mode' is On, each process is listed with
743 the cpu time that it and its dead children have used.
744 When Off, programs that fork into many separate tasks will
746 appear less demanding. For programs like 'init' or a shell
747 this is appropriate but for others, like compilers, perhaps
748 not. Experiment with two task windows sharing the same
749 sort field but with different 'S' states and see which rep‐
750 resentation you prefer.
751 After issuing this command, you'll be informed of the new
753 state of this toggle. If you wish to know in advance
754 whether or not 'Cumulative mode' is in effect, simply ask
755 for help and view the window summary on the second line.
756 ´u´ :Show_Specific_User_Only
758 You will be prompted to enter the name of the user to dis‐
759 play. Thereafter, in that task window only matching User
760 ID's will be shown, or possibly no tasks will be shown.
761 Later, if you wish to monitor all tasks again, re-issue
763 this command but just press <Enter> at the prompt, without
764 providing a name.
765 SIZE of task window
767 ´i´ :Idle_Processes_toggle
768 Displays all tasks or just active tasks. When this toggle
769 is Off, idled or zombied processes will not be displayed.
770 If this command is applied to the last task display when in
772 alternate-display mode, then it will not affect the win‐
773 dow's size, as all prior task displays will have already
774 been painted.
775 ´n´ or ´#´ :Set_Maximum_Tasks
777 You will be prompted to enter the number of tasks to dis‐
778 play. The lessor of your number and available screen rows
779 will be used.
780 When used in alternate-display mode, this is the command
782 that gives you precise control over the size of each cur‐
783 rently visible task display, except for the very last. It
784 will not affect the last window's size, as all prior task
785 displays will have already been painted.
786 Note: If you wish to increase the size of the last visible
788 task display when in alternate-display mode, simply
789 decrease the size of the task display(s) above it.
790 SORTING of task window
792 For compatibility, this top supports most of the former top sort
793 keys. Since this is primarily a service to former top users,
794 these commands do not appear on any help screen.
795 command sorted field supported
796 A start time (non-display) No
797 M %MEM Yes
798 N PID Yes
799 P %CPU Yes
800 T TIME+ Yes
801 Before using any of the following sort provisions, top suggests
803 that you temporarily turn on column highlighting using the 'x'
804 interactive command. That will help ensure that the actual sort
805 environment matches your intent.
806 The following interactive commands will only be honored when the
808 current sort field is visible. The sort field might not be vis‐
809 ible because:
810 1) there is insufficient Screen Width
811 2) the 'f' interactive command turned it Off
812 ´<´ :Move_Sort_Field_Left
814 Moves the sort column to the left unless the current sort
815 field is the first field being displayed.
816 ´>´ :Move_Sort_Field_Right
818 Moves the sort column to the right unless the current sort
819 field is the last field being displayed.
820 The following interactive commands will always be honored
822 whether or not the current sort field is visible.
823 ´F´ or ´O´ :Select_Sort_Field
825 These keys display a separate screen where you can change
826 which field is used as the sort column.
827 If a field is selected which was not previously being dis‐
829 played, it will be forced On when you return to the top
830 display. However, depending upon your screen width and the
831 order of your fields, this sort field may not be dis‐
832 playable.
833 This interactive command can be a convenient way to simply
835 verify the current sort field, when running top with column
836 highlighting turned Off.
837 ´R´ :Reverse/Normal_Sort_Field_toggle
839 Using this interactive command you can alternate between
840 high-to-low and low-to-high sorts.
841 Note: Field sorting uses internal values, not those in column
843 display. Thus, the TTY and WCHAN fields will violate strict
844 ASCII collating sequence.
845 3d. COLOR Mapping
847 When you issue the 'Z' interactive command, you will be presented
848 with a separate screen. That screen can be used to change the
849 colors in just the ´current' window or in all four windows before
850 returning to the top display.
851 Available interactive commands
853 4 upper case letters to select a target
854 8 numbers to select a color
855 normal toggles available
856 'B' :bold disable/enable
857 'b' :running tasks "bold"/reverse
858 'z' :color/mono
859 other commands available
860 'a'/'w' :apply, then go to next/prior
861 <Enter> :apply and exit
862 'q' :abandon current changes and exit
863 If your use 'a' or 'w' to cycle the targeted window, you will have
865 applied the color scheme that was displayed when you left that
866 window. You can, of course, easily return to any window and reap‐
867 ply different colors or turn colors Off completely with the 'z'
868 toggle.
869 The Color Mapping screen can also be used to change the ´current'
871 window/field group in either full-screen mode or alternate-display
872 mode. Whatever was targeted when 'q' or <Enter> was pressed will
873 be made current as you return to the top display.
874
877 4a. WINDOWS Overview
878 Field Groups/Windows:
879 In full-screen mode there is a single window represented by
880 the entire screen. That single window can still be changed
881 to display 1 of 4 different field groups (see the 'G'
882 interactive command, repeated below). Each of the 4 field
883 groups has a unique separately configurable summary area
884 and its own configurable task area.
885 In alternate-display mode, those 4 underlying field groups
887 can now be made visible simultaneously, or can be turned
888 Off individually at your command.
889 The summary area will always exist, even if it's only the
891 message line. At any given time only one summary area can
892 be displayed. However, depending on your commands, there
893 could be from zero to four separate task displays currently
894 showing on the screen.
895 Current Window:
897 The ´current' window is the window associated with the sum‐
898 mary area and the window to which task related commands are
899 always directed. Since in alternate-display mode you can
900 toggle the task display Off, some commands might be
901 restricted for the ´current' window.
902 A further complication arises when you have toggled the
904 first summary area line Off. With the loss of the window
905 name (the 'l' toggled line), you'll not easily know what
906 window is the ´current' window.
907 4b. COMMANDS for Windows
909 ´-´ and ´_´ :Show/Hide_Window(s)_toggles
910 The '-' key turns the ´current' window's task display On
911 and Off. When On, that task area will show a minimum of
912 the columns header you've established with the 'f' and 'o'
913 commands. It will also reflect any other task area
914 options/toggles you've applied yielding zero or more tasks.
915 The '_' key does the same for all task displays. In other
917 words, it switches between the currently visible task dis‐
918 play(s) and any task display(s) you had toggled Off. If
919 all 4 task displays are currently visible, this interactive
920 command will leave the summary area as the only display
921 element.
922 * ´=´ and ´+´ :Equalize_(re-balance)_Window(s)
924 The '=' key forces the ´current' window's task display to
925 be visible. It also reverses any 'i' (idle tasks) and 'n'
926 (max tasks) commands that might be active.
927 The '+' key does the same for all windows. The four task
929 displays will reappear, evenly balanced. They will also
930 have retained any customizations you had previously
931 applied, except for the 'i' (idle tasks) and 'n' (max
932 tasks) commands.
933 * ´A´ :Alternate_Display_Mode_toggle
935 This command will switch between full-screen mode and
936 alternate-display mode.
937 The first time you issue this command, all four task dis‐
939 plays will be shown. Thereafter when you switch modes, you
940 will see only the task display(s) you've chosen to make
941 visible.
942 * ´a´ and ´w´ :Next_Window_Forward/Backward
944 This will change the ´current' window, which in turn
945 changes the window to which commands are directed. These
946 keys act in a circular fashion so you can reach any desired
947 ´current' window using either key.
948 Assuming the window name is visible (you have not toggled
950 'l' Off), whenever the ´current' window name loses its
951 emphasis/color, that's a reminder the task display is Off
952 and many commands will be restricted.
953 * ´G´ :Choose_Another_Window/Field_Group
955 You will be prompted to enter a number between 1 and 4 des‐
956 ignating the window/field group which should be made the
957 ´current' window.
958 In full-screen mode, this command is necessary to alter the
960 ´current' window. In alternate-display mode, it is simply
961 a less convenient alternative to the 'a' and 'w' commands.
962 ´g´ :Change_Window/Field_Group_Name
964 You will be prompted for a new name to be applied to the
965 ´current' window. It does not require that the window name
966 be visible (the 'l' toggle to be On).
967 * The interactive commands shown with an asterisk ('*') have use
969 beyond alternate-display mode.
970 ´=', 'A', 'G' are always available
971 ´a', 'w' act the same when color mapping
972
975 5a. SYSTEM Configuration File
976 The presence of this file will influence which version of the
977 'help' screen is shown to an ordinary user. More importantly, it
978 will limit what ordinary users are allowed to do when top is run‐
979 ning. They will not be able to issue the following commands.
980 k Kill a task
981 r Renice a task
982 d or s Change delay/sleep interval
983 The system configuration file is not created by top. Rather, you
985 create this file manually and place it in the /etc directory. Its
986 name must be 'toprc' and must have no leading '.' (period). It
987 must have only two lines.
988 Here is an example of the contents of /etc/toprc:
990 s # line 1: 'secure' mode switch
991 5.0 # line 2: 'delay' interval in seconds
992 5b. PERSONAL Configuration File
994 This file is written as '$HOME/.your-name-4-top' + 'rc'. Use the
995 'W' interactive command to create it or update it.
996 Here is the general layout:
998 global # line 1: the program name/alias notation
999 " # line 2: id,altscr,irixps,delay,curwin
1000 per ea # line a: winname,fieldscur
1001 window # line b: winflags,sortindx,maxtasks
1002 " # line c: summclr,msgsclr,headclr,taskclr
1003 If the $HOME variable is not present, top will try to write the
1005 personal configuration file to the current directory, subject to
1006 permissions.
1007
1010 Many of these 'tricks' work best when you give top a scheduling
1011 boost. So plan on starting him with a nice value of -10, assuming
1012 you've got the authority.
1013 6a. Kernel Magic
1015 For these stupid tricks, top needs full-screen mode.
1016 -*- The user interface, through prompts and help, intentionally
1018 implies that the delay interval is limited to tenths of a
1019 second. However, you're free to set any desired delay. If
1020 you want to see Linux at his scheduling best, try a delay of
1021 .09 seconds or less.
1022 For this experiment, under x-windows open an xterm and maxi‐
1024 mize it. Then do the following:
1025 . provide a scheduling boost and tiny delay via:
1026 nice -n -10 top -d.09
1027 . keep sorted column highlighting Off to minimize
1028 path length
1029 . turn On reverse row highlighting for emphasis
1030 . try various sort columns (TIME/MEM work well),
1031 and normal or reverse sorts to bring the most
1032 active processes into view
1033 What you'll see is a very busy Linux doing what he's always
1035 done for you, but there was no program available to illus‐
1036 trate this.
1037 -*- Under an xterm using 'white-on-black' colors, try setting
1039 top's task color to black and be sure that task highlighting
1040 is set to bold, not reverse. Then set the delay interval to
1041 around .3 seconds.
1042 After bringing the most active processes into view, what
1044 you'll see are the ghostly images of just the currently run‐
1045 ning tasks.
1046 -*- Delete the existing rcfile, or create a new symlink. Start
1048 this new version then type 'T' (a secret key, see topic 3c.
1049 TASK Area Commands, Sorting) followed by 'W' and 'q'.
1050 Finally, restart the program with -d0 (zero delay).
1051 Your display will be refreshed at three times the rate of the
1053 former top, a 300% speed advantage. As top climbs the TIME
1054 ladder, be as patient as you can while speculating on whether
1055 or not top will ever reach the top.
1056 6b. Bouncing Windows
1058 For these stupid tricks, top needs alternate-display mode.
1059 -*- With 3 or 4 task displays visible, pick any window other than
1061 the last and turn idle processes Off. Depending on where you
1062 applied 'i', sometimes several task displays are bouncing and
1063 sometimes it's like an accordion, as top tries his best to
1064 allocate space.
1065 -*- Set each window's summary lines differently: one with no mem‐
1067 ory; another with no states; maybe one with nothing at all,
1068 just the message line. Then hold down 'a' or 'w' and watch a
1069 variation on bouncing windows -- hopping windows.
1070 -*- Display all 4 windows and for each, in turn, set idle pro‐
1072 cesses to Off. You've just entered the "extreme bounce"
1073 zone.
1074 6c. The Big Bird Window
1076 This stupid trick also requires alternate-display mode.
1077 -*- Display all 4 windows and make sure that 1:Def is the ´cur‐
1079 rent' window. Then, keep increasing window size until the
1080 all the other task displays are "pushed out of the nest".
1081 When they've all been displaced, toggle between all visi‐
1083 ble/invisible windows. Then ponder this:
1084 is top fibbing or telling honestly your imposed truth?
1085
1088 Send bug reports to:
1089 Albert D. Cahalan, <albert@users.sf.net>
1090 The top command calculates Cpu(s) by looking at the change in CPU
1092 time values between samples. When you first run it, it has no pre‐
1093 vious sample to compare to, so these initial values are the per‐
1094 centages since boot. It means you need at least two loops or you
1095 have to ignore summary output from the first loop. This is prob‐
1096 lem for example for batch mode. There is a possible workaround if
1097 you define the CPULOOP=1 environment variable. The top command
1098 will be run one extra hidden loop for CPU data before standard
1099 output.
1100
1102 The original top was written by Roger Binns, based on Branko
1103 Lankester's <lankeste@fwi.uva.nl> ps program.
1104 Robert Nation <nation@rocket.sanders.lockheed.com> adapted it for
1106 the proc file system.
1107 Helmut Geyer <Helmut.Geyer@iwr.uni-heidelberg.de> added support
1109 for configurable fields.
1110 Plus many other individuals contributed over the years.
1112
1115 This entirely new and enhanced replacement was written by:
1116 Jim / James C. Warner, <warnerjc@worldnet.att.net>
1117 With invaluable help from:
1119 Albert D. Cahalan, <albert@users.sf.net>
1120 Craig Small, <csmall@small.dropbear.id.au>
1121
1124 free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1).
1125Linux September 2002 TOP(1)