xref: /freebsd/share/man/man9/vm_map_find.9 (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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26.\" $FreeBSD$
27.\"
28.Dd July 19, 2003
29.Dt vm_map_find 9
30.Sh NAME
31.Nm vm_map_find
32.Nd find a free region within a map, and optionally map a vm_object
33.Sh SYNOPSIS
34.In sys/param.h
35.In vm/vm.h
36.In vm/vm_map.h
37.Ft int
38.Fn vm_map_find "vm_map_t map" "vm_object_t object" "vm_ooffset_t offset" "vm_offset_t *addr" "vm_size_t length" "boolean_t find_space" "vm_prot_t prot" "vm_prot_t max" "int cow"
39.Sh DESCRIPTION
40The
41.Fn vm_map_find
42function attempts to find a free region in the target
43.Fa map ,
44with the given
45.Fa length ,
46and will also optionally create a mapping of
47.Fa object .
48.Pp
49The arguments
50.Fa offset ,
51.Fa prot ,
52.Fa max ,
53and
54.Fa cow
55are passed unchanged to
56.Xr vm_map_insert 9
57when creating the mapping, if and only if a free region is found.
58.Pp
59If
60.Fa object
61is non-NULL, the reference count on the object must be incremented
62by the caller before calling this function to account for the new entry.
63.Pp
64If
65.Fa find_space
66is
67.Dv TRUE ,
68the function will call
69.Xr vm_map_findspace 9
70to discover a free region.
71.Sh IMPLEMENTATION NOTES
72This function acquires a lock on
73.Fa map
74by calling
75.Xr vm_map_lock 9 ,
76and holds it until the function returns.
77.Pp
78The search for a free region is defined to be first-fit, from the address
79.Fa addr
80onwards.
81.Sh RETURN VALUES
82The
83.Fn
84function returns
85.Dv KERN_SUCCESS
86if space for the mapping could be found and
87the mapping was successfully created.
88If space could not be found in the map,
89.Dv KERN_NO_SPACE
90will be returned.
91If the discovered range turned out to be bogus,
92.Dv KERN_INVALID_ADDRESS
93will be returned.
94.Sh SEE ALSO
95.Xr vm_map 9 ,
96.Xr vm_map_findspace 9 ,
97.Xr vm_map_insert 9 ,
98.Xr vm_map_lock 9
99.Sh AUTHORS
100This man page was written by
101.An Bruce M Simpson Aq bms@spc.org .
102