xref: /freebsd/share/man/man9/vm_map_findspace.9 (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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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