How to read the summary area fields describing CPU statistics from the top command log ?

When you run the "top" command in SSH , you get the results as following :

top - 19:46:04 up 18 days, 4 min, 1 user, load average: 0.16, 0.24, 0.27

Tasks: 138 total, 1 running, 137 sleeping, 0 stopped, 0 zombie

Cpu(s): 5.1%us, 2.4%sy, 0.2%ni, 89.5%id, 2.7%wa, 0.0%hi, 0.0%si, 0.0%st

Mem: 3887124k total, 3420008k used, 467116k free, 419972k buffers

Swap: 8392696k total, 269884k used, 8122812k free, 1395624k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

1 **** 20 0 19356 1052 836 S 0.0 0.0 0:06.04 init

2 **** 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd

3 **** RT 0 0 0 0 S 0.0 0.0 0:10.97 migration/0

4 **** 20 0 0 0 0 S 0.0 0.0 0:50.46 ksoftirqd/0

In this cpu(s) line can be read as following :

{ Cpu(s): 5.1%us, 2.4%sy, 0.2%ni, 89.5%id, 2.7%wa, 0.0%hi, 0.0%si, 0.0%st }

us = user mode

sy = system mode

ni = low priority user mode (nice)

id = idle task

wa = I/O waiting

hi = servicing IRQs

si = servicing soft IRQs

st = steal (time given to other DomU instances)