task_ppid_nr_ns
ppid = task_ppid_nr_ns(p, ns);
ppid = task_ppid_nr_ns(task, ns);
return task_ppid_nr_ns(tsk, NULL);
return task_ppid_nr_ns(tsk, &init_pid_ns);
stats->ac_ppid = task_ppid_nr_ns(tsk, pid_ns);