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.\" Hey Emacs! This file is -*- nroff -*- source.
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.\"
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.\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu)
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.\" Portions extracted from linux/mm/swap.c:
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.\" Copyright (C) 1991, 1992 Linus Torvalds
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.\"
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.\" Permission is granted to make and distribute verbatim copies of this
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.\" manual provided the copyright notice and this permission notice are
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.\" preserved on all copies.
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.\"
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.\" Permission is granted to copy and distribute modified versions of this
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.\" manual under the conditions for verbatim copying, provided that the
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.\" entire resulting derived work is distributed under the terms of a
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.\" permission notice identical to this one.
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.\"
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.\" Since the Linux kernel and libraries are constantly changing, this
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.\" manual page may be incorrect or out-of-date. The author(s) assume no
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.\" responsibility for errors or omissions, or for damages resulting from
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.\" the use of the information contained herein. The author(s) may not
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.\" have taken the same level of care in the production of this manual,
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.\" which is licensed free of charge, as they might when working
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.\" professionally.
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.\"
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" the source, must acknowledge the copyright and authors of this work.
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.\"
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.\" Modified 21 Aug 1994 by Michael Chastain <mec@shell.portal.com>:
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.\" Added text about calling restriction (new in kernel 1.1.20 I believe).
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.\" N.B. calling "idle" from user process used to hang process!
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.\" Modified Thu Oct 31 14:41:15 1996 by Eric S. Raymond <esr@thyrsus.com>
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.\" "
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.TH IDLE 2 1994-08-21 "Linux 1.1.46" "Linux Programmer's Manual"
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.SH NAME
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idle \- make process 0 idle
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.SH SYNOPSIS
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.B #include <unistd.h>
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.sp
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.B int idle(void);
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.SH DESCRIPTION
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.BR idle ()
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is an internal system call used during bootstrap.
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It marks the process's pages as swappable, lowers its priority,
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and enters the main scheduling loop.
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.BR idle ()
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never returns.
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.PP
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Only process 0 may call
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.BR idle ().
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Any user process, even a process with superuser permission,
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will receive
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.BR EPERM .
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.SH "RETURN VALUE"
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.BR idle ()
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never returns for process 0, and always returns \-1 for a user process.
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.SH ERRORS
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.TP
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.B EPERM
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Always, for a user process.
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.SH "CONFORMING TO"
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This function is Linux-specific, and should not be used in programs
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intended to be portable.
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.SH NOTES
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Since 2.3.13 this system call does not exist anymore.
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