I have a simple C program that open the file in a loop:

```
for(i = 1; i <= loopCount; ++i)
{

   FILE *fp;
   char buff[255];

   fp = fopen("test.txt", "r");
   fgets(buff, 255, (FILE*)fp);
   /* do something */
   fclose(fp);
}

```

I want to know each time how many bytes read from cache and how many bytes read from disk and log it. (I run it in Ubuntu 16.04 if it matter) is there any way I could find that? has any one any idea?