什么是CPU时间

ywchen2000

cpu时间是user time+system time吗???

newroot

好像不是，real time = sys + user + other
cpu时间好像不是这个意思！！

rickxbx

http://www.webopedia.com/TERM/C/CPU_time.html

CPU Time:

The amount of time the CPU is actually executing instructions. During the execution of most programs, the CPU sits idle much of the time while the computer fetches data from the keyboard or disk, or sends data to an output device. The CPU time of an executing program, therefore, is generally much less than the total execution time of the program. Multitasking operating systems take advantage of this by sharing the CPU among several programs.

CPU times are used for a variety of purposes: to compare the speed of two different processors, to gauge how CPU-intensive a program is, and to measure the amount of processing time being allocated to different programs in a multitasking environment.

不知道你所说的cpu时间指的是什么

ywchen2000

那在LINUX怎么得到这个时间呢?????

rickxbx

用time命令可以获取一个应用程序所使用的real time（实时时间，进程所占用所有时间），user time（用户态时间，进程在用户态运行时的时间），system time（系统时间，进程在内核态运行时的时间）

ywchen2000

我是说在我的程序中???

rickxbx

Post by ywchen2000
我是说在我的程序中???

man 2 times

另外，可参见apue的10.16节

btw：如果没有那本书，我可以发给你

ywchen2000

呵呵,我要,ywchen2000@yahoo.com.cn

ywchen2000

感谢rickxbx提供的帮助

rickxbx

Post by ywchen2000
感谢rickxbx提供的帮助

呵呵，不谢。
电子书收到了？