#include <stdio.h>

#include <sys/types.h>

#include <unistd.h>



int main (void) {

  printf ("%d
", (int) getpid ());

  return 0;

}

struct pid * fastcall find_pid(enum pid_type type, int nr)

{

        struct hlist_node *elem;

        struct pid *pid;



        for (elem = (&pid_hash[type][hash_long((unsigned long)nr,

pidhash_shift)])->first; elem && ({ prefetch(elem->next); 1;})

&& ({ pid = hlist_entry(elem, typeof(*pid), pid_chain); 1;}); elem =

elem->next) {



                if (pid->nr == nr)

                        return pid;

        }

        return NULL;

}


就是从链表里挨个找，有空的就用。