Unix/Linux: system load

load的就是一定时间内计算机有多少个active_tasks，也就是说是计算机的任务执行队列的长度，cpu计算的队列。


The comparative study of different load indices carried out by Ferrari et al.^[2] reported that CPU load information based upon the CPU queue length does much better in load balancing compared to CPU utilization
http://os.51cto.com/art/201012/240719.htm

http://en.wikipedia.org/wiki/Load_(computing)