Programmatically calculating Cache Line Size

Cache Line Size

#include<stdlib.h>
#include<stdio.h>
#include<sys/time.h>
#include<iostream>
#include <ctime>
#include <cstdio>
#include <fstream>
#include<istream>

using namespace std;

void clflush(volatile char *p){
         asm volatile ("clflush (%0)" :: "r"(p));
}


int main(){
  
	ofstream myfile;
	myfile.open("data.txt");

	
	srand (time(NULL));
	struct timeval tm;
    int big_size= 5000000;
	int small_size  = 500000;
	
    int j =0;
    char t;
	int step_size = 64;
	long start,end,accumulate=0,accumulate1=0;
	int ind;	
	

    volatile char* a = new char[big_size];
    for(int i =0;i<big_size;i++){
            a[i] =1;
    }
    
  step_size =1;
  int count[100];  
  int b=0;
  for(int hjk=0;hjk<100;hjk++)
    count[hjk]=0;
    
  for(int i=0;i<10000;i++){
	
	 
	
	b=0;
	step_size =1;
	while(step_size < 4096){ 
	 gettimeofday(&tm,NULL);
     start = tm.tv_sec*1000000 + tm.tv_usec; 
     t=a[step_size]; 
	 gettimeofday(&tm,NULL);
     end = tm.tv_sec*1000000 + tm.tv_usec; 
     clflush(&a[step_size]);
	count[b++] += end - start;
    step_size *=2; 
   }  
}
   step_size=1;
   b=0;
   while(step_size < 4096){
	cout<<step_size<<' '<<count[b]<<endl;
	step_size *=2;
	b++;
}     
	   
	   
	   
	     
return 0;
}