Table of Processes

top

Provides a dynamic real-time view of a running system.

Load is a complex value, designating the balance between required and available CPU power.
Load <1: The system has some idle time
Load =1: The system has as much work as it can handle
Load >1: The system has to prioritize some processes over others
Load >3: The system is probably not fit for the current workload
Load >10: The system may have a serious problem
Load >30: System stability is critical, even shells may freeze

Abbrevations:
us: user space
sy: system/kernel
ni: processes with nice value
id: idle time
wa: wait time
hi: hardware interrupt time
si: software interrupt time
st: steal time, time taken away from the vm by the hypervisor

Use

top show table, sorted by CPU load

Useful Flags

-u <user> only show processes from <user>

Useful Keys

View
arrow keys scroll the list
t change CPU display
m change memory display
1 combine/split CPUs
e change list memory units
E change summary memory units
l toggle summary list
z toggle color
y toggle running task highlight
x toggle sort column highlight
b toggle bold highlight
c toggle path
V toggle tree
i toggle inactive tasks
Sort
P sort by %CPU (default)
M sort by %MEM
N sort by PID
T sort by TIME+
Filter
u prompt to enter specific username or UID
n prompt to show only N processes
o prompt to enter filter, eg. %MEM>5.0
= clear filter
Modify
r prompt to enter <pid> to renice
k prompt to enter <pid> to kill (SIGTERM)