redhat man page for idle

IDLE(2) 						     Linux Programmer's Manual							   IDLE(2)

NAME
       idle - make process 0 idle

SYNOPSIS
       #include <unistd.h>

       int idle(void);

DESCRIPTION
       idle is an internal system call used during bootstrap.  It marks the process's pages as swappable, lowers its priority, and enters the main
       scheduling loop.  idle never returns.

       Only process 0 may call idle.  Any user process, even a process with super-user permission, will receive EPERM.

RETURN VALUE
       idle never returns for process 0, and always returns -1 for a user process.

ERRORS
       EPERM  Always, for a user process.

CONFORMING TO
       This function is Linux-specific, and should not be used in programs intended to be portable.

NOTES
       Since 2.3.13 this system call does not exist anymore.

Linux 1.1.46							    1994-08-21								   IDLE(2)