| .\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) |
| .\" Portions extracted from linux/mm/swap.c: |
| .\" Copyright (C) 1991, 1992 Linus Torvalds |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
| .\" preserved on all copies. |
| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
| .\" |
| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" %%%LICENSE_END |
| .\" |
| .\" Modified 21 Aug 1994 by Michael Chastain <mec@shell.portal.com>: |
| .\" Added text about calling restriction (new in kernel 1.1.20 I believe). |
| .\" N.B. calling "idle" from user process used to hang process! |
| .\" Modified Thu Oct 31 14:41:15 1996 by Eric S. Raymond <esr@thyrsus.com> |
| .\" " |
| .TH IDLE 2 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| idle \- make process 0 idle |
| .SH SYNOPSIS |
| .nf |
| .B #include <unistd.h> |
| .PP |
| .B int idle(void); |
| .fi |
| .SH DESCRIPTION |
| .BR 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. |
| .BR idle () |
| never returns. |
| .PP |
| Only process 0 may call |
| .BR idle (). |
| Any user process, even a process with superuser permission, |
| will receive |
| .BR EPERM . |
| .SH RETURN VALUE |
| .BR idle () |
| never returns for process 0, and always returns \-1 for a user process. |
| .SH ERRORS |
| .TP |
| .B EPERM |
| Always, for a user process. |
| .SH VERSIONS |
| Since Linux 2.3.13, this system call does not exist anymore. |
| .SH CONFORMING TO |
| This function is Linux-specific, and should not be used in programs |
| intended to be portable. |