xref: /freebsd/share/man/man9/vm_map_find.9 (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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26.\" $FreeBSD$
27.\"
28.Dd July 19, 2003
29.Dt VM_MAP_FIND 9
30.Os
31.Sh NAME
32.Nm vm_map_find
33.Nd find a free region within a map, and optionally map a vm_object
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_find
40.Fa "vm_map_t map" "vm_object_t object" "vm_ooffset_t offset"
41.Fa "vm_offset_t *addr" "vm_size_t length" "boolean_t find_space"
42.Fa "vm_prot_t prot" "vm_prot_t max" "int cow"
43.Fc
44.Sh DESCRIPTION
45The
46.Fn vm_map_find
47function attempts to find a free region in the target
48.Fa map ,
49with the given
50.Fa length ,
51and will also optionally create a mapping of
52.Fa object .
53.Pp
54The arguments
55.Fa offset ,
56.Fa prot ,
57.Fa max ,
58and
59.Fa cow
60are passed unchanged to
61.Xr vm_map_insert 9
62when creating the mapping, if and only if a free region is found.
63.Pp
64If
65.Fa object
66is
67.Pf non- Dv NULL ,
68the reference count on the object must be incremented
69by the caller before calling this function to account for the new entry.
70.Pp
71If
72.Fa find_space
73is
74.Dv TRUE ,
75the function will call
76.Xr vm_map_findspace 9
77to discover a free region.
78.Sh IMPLEMENTATION NOTES
79This function acquires a lock on
80.Fa map
81by calling
82.Xr vm_map_lock 9 ,
83and holds it until the function returns.
84.Pp
85The search for a free region is defined to be first-fit, from the address
86.Fa addr
87onwards.
88.Sh RETURN VALUES
89The
90.Fn vm_map_find
91function returns
92.Dv KERN_SUCCESS
93if space for the mapping could be found and
94the mapping was successfully created.
95If space could not be found in the map,
96.Dv KERN_NO_SPACE
97will be returned.
98If the discovered range turned out to be bogus,
99.Dv KERN_INVALID_ADDRESS
100will be returned.
101.Sh SEE ALSO
102.Xr vm_map 9 ,
103.Xr vm_map_findspace 9 ,
104.Xr vm_map_insert 9 ,
105.Xr vm_map_lock 9
106.Sh AUTHORS
107This man page was written by
108.An Bruce M Simpson Aq bms@spc.org .
109