mirror of
https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git
synced 2024-11-22 11:14:18 +01:00
8269e7673c
Remove core system call implementations and documentation to lib/libsys and lib/libsys/<arch> from lib/libc/sys and lib/libc/<arch>/<sys>. Update paths to allow libc to find them in their new home. Reviewed by: kib, emaste, imp Pull Request: https://github.com/freebsd/freebsd-src/pull/908
160 lines
4.5 KiB
Groff
160 lines
4.5 KiB
Groff
.\" Copyright (c) 1980, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd December 8, 2021
|
|
.Dt SWAPON 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm swapon , swapoff
|
|
.Nd control devices for interleaved paging/swapping
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.It vm/vm_param.h
|
|
.It vm/swap_pager.h
|
|
.In unistd.h
|
|
.Ft int
|
|
.Fn swapon "const char *special"
|
|
.Ft int
|
|
.Fn swapoff "const char *special" "u_int flags"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn swapon
|
|
system call
|
|
makes the block device
|
|
.Fa special
|
|
available to the system for
|
|
allocation for paging and swapping.
|
|
The names of potentially
|
|
available devices are known to the system and defined at system
|
|
configuration time.
|
|
The size of the swap area on
|
|
.Fa special
|
|
is calculated at the time the device is first made available
|
|
for swapping.
|
|
.Pp
|
|
The
|
|
.Fn swapoff
|
|
system call disables paging and swapping on the given device.
|
|
All associated swap metadata are deallocated, and the device
|
|
is made available for other purposes.
|
|
.Pp
|
|
The
|
|
.Fa special
|
|
argument points to the name of the device or file used for swapping.
|
|
.The
|
|
.Va flags
|
|
argument takes the following flags:
|
|
.Bl -tag -width SWAPOFF_FORCE
|
|
.It Dv SWAPOFF_FORCE
|
|
Overrides a very conservative check that prevents swapoff
|
|
if the total amount of free memory and remaining swap
|
|
devices space might be unsufficient for the system to continue
|
|
operating.
|
|
.El
|
|
.Sh RETURN VALUES
|
|
If an error has occurred, a value of -1 is returned and
|
|
.Va errno
|
|
is set to indicate the error.
|
|
.Sh ERRORS
|
|
Both
|
|
.Fn swapon
|
|
and
|
|
.Fn swapoff
|
|
can fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ENOTDIR
|
|
A component of the path prefix is not a directory.
|
|
.It Bq Er ENAMETOOLONG
|
|
A component of a pathname exceeded 255 characters,
|
|
or an entire path name exceeded 1023 characters.
|
|
.It Bq Er ENOENT
|
|
The named device does not exist.
|
|
.It Bq Er EACCES
|
|
Search permission is denied for a component of the path prefix.
|
|
.It Bq Er ELOOP
|
|
Too many symbolic links were encountered in translating the pathname.
|
|
.It Bq Er EPERM
|
|
The caller is not the super-user.
|
|
.It Bq Er EFAULT
|
|
The
|
|
.Fa special
|
|
argument
|
|
points outside the process's allocated address space.
|
|
.El
|
|
.Pp
|
|
Additionally,
|
|
.Fn swapon
|
|
can fail for the following reasons:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ENOTBLK
|
|
The
|
|
.Fa special
|
|
argument
|
|
is not a block device.
|
|
.It Bq Er EBUSY
|
|
The device specified by
|
|
.Fa special
|
|
has already
|
|
been made available for swapping
|
|
.It Bq Er ENXIO
|
|
The major device number of
|
|
.Fa special
|
|
is out of range (this indicates no device driver exists
|
|
for the associated hardware).
|
|
.It Bq Er EIO
|
|
An I/O error occurred while opening the swap device.
|
|
.It Bq Er EINTEGRITY
|
|
Corrupted data was detected while reading from the file system to open the
|
|
swap device.
|
|
.El
|
|
.Pp
|
|
Lastly,
|
|
.Fn swapoff
|
|
can fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The system is not currently swapping to
|
|
.Fa special .
|
|
.It Bq Er ENOMEM
|
|
Not enough virtual memory is available to safely disable
|
|
paging and swapping to the given device.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr config 8 ,
|
|
.Xr swapon 8 ,
|
|
.Xr sysctl 8
|
|
.Sh HISTORY
|
|
The
|
|
.Fn swapon
|
|
system call appeared in
|
|
.Bx 4.0 .
|
|
The
|
|
.Fn swapoff
|
|
system call appeared in
|
|
.Fx 5.1 .
|