top的输出中的一些东西非常简单,比如内存和交换使用.但是负载平均数有点神秘：这三个数字是什么意思？另外,僵尸程序究竟是什么？它和睡眠者有什么不同？
top - 13:20:58 up 69 days,7:07,1 user,load average: 0.03,0.02,0.00 Tasks: 80 total,1 running,79 sleeping,0 stopped,0 zombie cpu(s): 0.0% us,0.2% sy,0.0% ni,99.8% id,0.0% wa,0.0% hi,0.0% si Mem: 8054888k total,7975100k used,79788k free,130240k buffers Swap: 1572856k total,84k used,1572772k free,6393160k cached