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

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

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

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

VIRT = SWAP + RES.

RES = CODE + DATA.

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

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

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

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

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

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

Typing ’h’ or ’?’ on that help screen will take you to help for those interactive commands applicable to alternate-display mode.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

After bringing the most active processes into view, what you’ll see are the ghostly images of just the currently running tasks.

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

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