convert jiffies to seconds

Question

I\'ve got a piece of userspace code which is parsing /proc/PID/task/TID/stat to get the cpu usage. I can use HZ to get the jiffies per second but this code could move to an

Answer 1

Source of "ps" command include file to get value of HZ.

They also look for an "ELF note" with number 17 to find value of HZ (sysinfo.c):

 //extern char** environ;

 /* for ELF executables, notes are pushed before environment and args */
 static unsigned long find_elf_note(unsigned long findme){
   unsigned long *ep = (unsigned long *)environ;
   while(*ep++);
   while(*ep){
     if(ep[0]==findme) return ep[1];
     ep+=2;
   }
   return NOTE_NOT_FOUND;
 }
 [...]
 hz = find_elf_note(17);

I have to admit it look weird for me since ELF notes is a section defined during compilation.