xref: /freebsd/share/man/man9/vm_map_findspace.9 (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1.\"
2.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.\" $FreeBSD$
27.\"
28.Dd July 19, 2003
29.Dt VM_MAP_FINDSPACE 9
30.Os
31.Sh NAME
32.Nm vm_map_findspace
33.Nd find a free region within a map
34.Sh SYNOPSIS
35.In sys/param.h
36.In vm/vm.h
37.In vm/vm_map.h
38.Ft int
39.Fo vm_map_findspace
40.Fa "vm_map_t map" "vm_offset_t start" "vm_size_t length" "vm_offset_t *addr"
41.Fc
42.Sh DESCRIPTION
43The
44.Fn vm_map_findspace
45function attempts to find a region with sufficient space in the
46.Fa map
47for an object of size
48.Fa length
49at the address
50.Fa addr .
51.Sh IMPLEMENTATION NOTES
52It is the caller's responsibility to obtain a lock on the
53.Fa map
54using
55.Xr vm_map_lock 9
56before calling this function.
57.Pp
58This routine may call
59.Xr pmap_growkernel 9
60to grow the kernel's address space, if and only if the mapping is being
61made within the kernel address space, and if insufficient space remains
62in the
63.Va kernel_map .
64.Sh RETURN VALUES
65The
66.Fn vm_map_findspace
67function returns the value 0 if successful, and
68.Fa *addr
69will contain the first virtual address in the found region;
70otherwise, the value 1 is returned.
71.Sh SEE ALSO
72.Xr pmap_growkernel 9 ,
73.Xr vm_map 9 ,
74.Xr vm_map_entry_resize_free 9 ,
75.Xr vm_map_lock 9
76.Sh AUTHORS
77This manual page was written by
78.An Bruce M Simpson Aq Mt bms@spc.org .
79