x86计算CPU频率示例

#include                                 

#include                                

#include                                

#include                                

#include                                

#include                                  

#include                             

#include                              

#include                                 

#include                                

#include                                 

                                                   

#define ns 1000000000                             

                                                  

                                                   

//  Linux/GCC                                     

                                                   

static inline uint64_t get_cycle_count()          

{                                                 

    unsigned int lo,hi;                           

    __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));

    return ((uint64_t)hi << 32) | lo;             

}                                                 

                                                   

int main(int argc,char ** argv)                   

{                                                 

                                                   

    int i = 0;                                    

    uint64_t start,end;                             

    int ms = 700;                            

    for(i = 0; i < 100; i++)                      

    {                                             

        start = get_cycle_count();                  

        usleep(ms * 1000);                   

        end = get_cycle_count();                  

        printf("%u\n",(new-old)/(ms*1000));                                                                                                                                       

                                                   

    }                                             

}