idle - make process 0 idle
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
superuser permission, will receive EPERM.
idle() never returns for process 0, and always returns -1 for a user
EPERM Always, for a user process.
Since 2.3.13 this system call does not exist anymore.
This function is Linux-specific, and should not be used in programs
intended to be portable.
This page is part of release 3.24 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.