xref: /freebsd/share/man/man9/vm_map_findspace.9 (revision fe75646a0234a261c0013bf1840fdac4acaf0cec)
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26.Dd July 19, 2003
27.Dt VM_MAP_FINDSPACE 9
28.Os
29.Sh NAME
30.Nm vm_map_findspace
31.Nd find a free region within a map
32.Sh SYNOPSIS
33.In sys/param.h
34.In vm/vm.h
35.In vm/vm_map.h
36.Ft int
37.Fo vm_map_findspace
38.Fa "vm_map_t map" "vm_offset_t start" "vm_size_t length" "vm_offset_t *addr"
39.Fc
40.Sh DESCRIPTION
41The
42.Fn vm_map_findspace
43function attempts to find a region with sufficient space in the
44.Fa map
45for an object of size
46.Fa length
47at the address
48.Fa addr .
49.Sh IMPLEMENTATION NOTES
50It is the caller's responsibility to obtain a lock on the
51.Fa map
52using
53.Xr vm_map_lock 9
54before calling this function.
55.Pp
56This routine may call
57.Xr pmap_growkernel 9
58to grow the kernel's address space, if and only if the mapping is being
59made within the kernel address space, and if insufficient space remains
60in the
61.Va kernel_map .
62.Sh RETURN VALUES
63The
64.Fn vm_map_findspace
65function returns the value 0 if successful, and
66.Fa *addr
67will contain the first virtual address in the found region;
68otherwise, the value 1 is returned.
69.Sh SEE ALSO
70.Xr pmap_growkernel 9 ,
71.Xr vm_map 9 ,
72.Xr vm_map_entry_resize_free 9 ,
73.Xr vm_map_lock 9
74.Sh AUTHORS
75This manual page was written by
76.An Bruce M Simpson Aq Mt bms@spc.org .
77