Measuring execution time of a function inside linux kernel

Question

I am using Linux Security Module hooks to add some custom functionality to recv() system call. I want to measure the overhead of this functionality as compared to the pristi

Answer 1

I'm not sure you will obtain the result you want but we use the follwing code to have microseconds.

double Microsecs()
{
   static struct timeval _t;  
   static struct timezone tz;  
   gettimeofday(&_t, &tz);  
   return   (double)_t.tv_sec + (double)_t.tv_usec/(1000*1000);
}

Than you call it before and after the call you want and see how many time it.
We've been using this method to evaluate IO time monitoring read/write/seek operation in order to oprimize performance and we're having good results.

HTH.