top - 15:51:18 up 163 days, 21:16, 3 users, load average: 0.08, 0.03, 0.01
Tasks: 95 total, 2 running, 93 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.7 us, 0.0 sy, 0.0 ni, 96.7 id, 0.7 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 1023916 total, 533244 free, 100748 used, 389924 buff/cache
KiB Swap: 0 total, 0 free, 0 used. 739768 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3829 www-data 20 0 135316 37080 26336 S 2.3 3.6 0:01.19 apache2
1 root 20 0 23980 3880 2628 S 0.0 0.4 0:49.86 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 0:06.31 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
7 root 20 0 0 0 0 S 0.0 0.0 0:24.80 rcu_sched
- PR：优先级
- NI：nice值，负值为高优先级
- VIRT：进程虚拟内存总量（Kb）=SWAP + RES
- SHR： 共享内存大小
top模式下一些命令：
Help for Interactive Commands - procps-ng version 3.3.10
Window 1:Def: Cumulative mode Off. System: Delay 3.0 secs; Secure mode Off.
Z,B,E,e Global: 'Z' colors; 'B' bold; 'E'/'e' summary/task memory scale
l,t,m Toggle Summary: 'l' load avg; 't' task/cpu stats; 'm' memory info
0,1,2,3,I Toggle: '0' zeros; '1/2/3' cpus or numa node views; 'I' Irix mode
f,F,X Fields: 'f'/'F' add/remove/order/sort; 'X' increase fixed-width
L,&,<,> . Locate: 'L'/'&' find/again; Move sort column: '<'/'>' left/right
R,H,V,J . Toggle: 'R' Sort; 'H' Threads; 'V' Forest view; 'J' Num justify
c,i,S,j . Toggle: 'c' Cmd name/line; 'i' Idle; 'S' Time; 'j' Str justify
x,y . Toggle highlights: 'x' sort field; 'y' running tasks
z,b . Toggle: 'z' color/mono; 'b' bold/reverse (only if 'x' or 'y')
u,U,o,O . Filter by: 'u'/'U' effective/any user; 'o'/'O' other criteria
n,#,^O . Set: 'n'/'#' max tasks displayed; Show: Ctrl+'O' other filter(s)
C,... . Toggle scroll coordinates msg for: up,down,left,right,home,end
k,r Manipulate tasks: 'k' kill; 'r' renice
d or s Set update interval
W,Y Write configuration file 'W'; Inspect other output 'Y'
q Quit
( commands shown with '.' require a visible task display window )