问题
I want to get the overall total CPU usage for an application in C, the total CPU usage like we get in the TaskManager... I want to know ... for windows and linux :: current Total CPU utilization by all processes ..... as we see in the task manager.
回答1:
This is platform-specific:
- In Windows, you can use the GetProcessTimes() function.
- In Linux, you can actually just use
clock().
These can be used to measure the amount of CPU time taken between two time intervals.
EDIT :
To get the CPU consumption (as a percentage), you will need to divide the total CPU time by the # of logical cores that the OS sees, and then divided by the total wall-clock time:
% CPU usage = (CPU time) / (# of cores) / (wall time)
Getting the # of logical cores is also platform-specific:
- Windows: GetSystemInfo()
- Linux:
sysconf(_SC_NPROCESSORS_ONLN)
回答2:
Under POSIX, you want getrusage(2)'s ru_utime field. Use RUSAGE_SELF for just the calling process, and RUSAGE_CHILDEN for all terminated and wait(2)ed-upon children. Linux also supports RUSAGE_THREAD for just the calling thread. Use ru_stime if you want the system time, which can be summed with ru_utime for total time actively running (not wall time).
回答3:
It is usually operating system specific.
You could use the clock function, returning a clock_t (some integer type, like perhaps long). On Linux systems it measures the CPU time in microseconds.
回答4:
that is the exact thing I was looking for. Manipulating it in my way, I run it successfully.
Get total CPU usage
来源：https://stackoverflow.com/questions/8501706/how-to-get-the-cpu-usage-in-c