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[command]#top#
For each listed process, the [command]#top# command displays the process ID (`PID`), the effective username of the process owner (`USER`), the priority (`PR`), the nice value (`NI`), the amount of virtual memory the process uses (`VIRT`), the amount of non-swapped physical memory the process uses (`RES`), the amount of shared memory the process uses (`SHR`), the percentage of the CPU (`%CPU`) and memory (`%MEM`) usage, the cumulated CPU time (`TIME+`), and the name of the executable file (`COMMAND`). For example:
~]$ top
top - 19:22:08 up 5:53, 3 users, load average: 1.08, 1.03, 0.82
Tasks: 117 total, 2 running, 115 sleeping, 0 stopped, 0 zombie
Cpu(s): 9.3%us, 1.3%sy, 0.0%ni, 85.1%id, 0.0%wa, 1.7%hi, 0.0%si, 2.6%st
Mem: 761956k total, 617256k used, 144700k free, 24356k buffers
Swap: 1540092k total, 55780k used, 1484312k free, 256408k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
510 john 20 0 1435m 99m 18m S 9.0 13.3 3:30.52 gnome-shell
32686 root 20 0 156m 27m 3628 R 2.0 3.7 0:48.69 Xorg
2625 john 20 0 488m 27m 14m S 0.3 3.7 0:00.70 emacs
1 root 20 0 53128 2640 1152 S 0.0 0.3 0:02.83 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.01 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:00.18 ksoftirqd/0
5 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kworker/u:0
6 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
7 root RT 0 0 0 0 S 0.0 0.0 0:00.30 watchdog/0
8 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 cpuset
9 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 khelper
10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kdevtmpfs
11 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 netns
12 root 20 0 0 0 0 S 0.0 0.0 0:00.11 sync_supers
13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 bdi-default
14 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kintegrityd
15 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kblockd
xref:System_Monitoring_Tools.adoc#interactive-top-command[Interactive top commands] contains useful interactive commands that you can use with [command]#top#. For more information, refer to the *top*(1) manual page.
Interactive top commands
|Command|Description
|kbd:[Enter], kbd:[Space]|Immediately refreshes the display.
|kbd:[h], kbd:[?]|Displays a help screen.
|kbd:[k]|Kills a process. You are prompted for the process ID and the signal to send to it.
|kbd:[n]|Changes the number of displayed processes. You are prompted to enter the number.
|kbd:[u]|Sorts the list by user.
|kbd:[M]|Sorts the list by memory usage.
|kbd:[P]|Sorts the list by CPU usage.
|kbd:[q]|Terminates the utility and returns to the shell prompt.
Using the System Monitor Tool
indexterm:[gnome-system-monitor]indexterm:[System Monitor] The `Processes` tab of the [application]*System Monitor* tool allows you to view, search for, change the priority of, and kill processes from the graphical user interface.
To start the [application]*System Monitor* tool, either select menu:Applications[System Tools > `System Monitor`pass:attributes[{blank}]] from the Activities menu, or type [command]#gnome-system-monitor# at a shell prompt. Then click the `Processes` tab to view the list of running processes.
System Monitor — Processes
The Processes tab of the System Monitor application.
system-monitor-processes.png
For each listed process, the [application]*System Monitor* tool displays its name (`Process Name`), current status (`Status`), percentage of the memory usage (`% CPU`), nice value (`Nice`), process ID (`ID`), memory usage (`Memory`), the channel the process is waiting in (`Waiting Channel`), and additional details about the session (`Session`). To sort the information by a specific column in ascending order, click the name of that column. Click the name of the column again to toggle the sort between ascending and descending order.
By default, the [application]*System Monitor* tool displays a list of processes that are owned by the current user. Selecting various options from the View menu allows you to:
view only active processes,
view all processes,
view your processes,
view process dependencies,
view a memory map of a selected process,