xref: /netbsd/lib/libc/sys/swapon.3 (revision 6550d01e)
1.\"	$NetBSD: swapon.3,v 1.16 2010/05/31 12:16:20 njoly Exp $
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30.\"     @(#)swapon.2	8.1 (Berkeley) 6/4/93
31.\"
32.Dd June 4, 1993
33.Dt SWAPON 3
34.Os
35.Sh NAME
36.Nm swapon
37.Nd add a swap device for interleaved paging/swapping
38.Sh SYNOPSIS
39.In unistd.h
40.Ft int
41.Fn swapon "const char *special"
42.Sh DESCRIPTION
43.Bf -symbolic
44.\" This interface is available from the compatibility library, libcompat and
45This interface is provided for compatibility only and
46has been obsoleted by
47.Xr swapctl 2 .
48.Ef
49.Pp
50.Fn swapon
51makes the block device
52.Fa special
53available to the system for
54allocation for paging and swapping.
55The names of potentially available devices are known to the system
56and defined at system configuration time.
57The size of the swap area on
58.Fa special
59is calculated at the time the device is first made available
60for swapping.
61.Sh RETURN VALUES
62If an error has occurred, a value of \-1 is returned and
63.Va errno
64is set to indicate the error.
65.Sh ERRORS
66.Fn swapon
67succeeds unless:
68.Bl -tag -width ENAMETOOLONG
69.It Bq Er ENOTDIR
70A component of the path prefix is not a directory.
71.It Bq Er ENAMETOOLONG
72A component of a pathname exceeded
73.Brq Dv NAME_MAX
74characters, or an entire path name exceeded
75.Brq Dv PATH_MAX
76characters.
77.It Bq Er ENOENT
78The named device does not exist.
79.It Bq Er EACCES
80Search permission is denied for a component of the path prefix.
81.It Bq Er ELOOP
82Too many symbolic links were encountered in translating the pathname.
83.It Bq Er EPERM
84The caller is not the super-user.
85.It Bq Er ENOTBLK
86.Fa special
87is not a block device.
88.It Bq Er EBUSY
89The device specified by
90.Fa special
91has already
92been made available for swapping
93.It Bq Er EINVAL
94The device configured by
95.Fa special
96was not
97configured into the system as a swap device.
98.It Bq Er ENXIO
99The major device number of
100.Fa special
101is out of range (this indicates no device driver exists
102for the associated hardware).
103.It Bq Er EIO
104An I/O error occurred while opening the swap device.
105.It Bq Er EFAULT
106.Fa special
107points outside the process's allocated address space.
108.El
109.Sh SEE ALSO
110.Xr swapctl 2 ,
111.Xr swapctl 8 ,
112.Xr swapon 8
113.Sh HISTORY
114The
115.Fn swapon
116function call appeared in
117.Bx 4.0
118and was removed
119.Nx 1.3
120.Sh BUGS
121This call will be upgraded in future versions of the system.
122