Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
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$FreeBSD$

.Dd May 10, 2008 .Dt VM_MAP_FIND 9 .Os .Sh NAME .Nm vm_map_find .Nd find a free region within a map, and optionally map a vm_object .Sh SYNOPSIS n sys/param.h n vm/vm.h n vm/vm_map.h .Ft int .Fo vm_map_find .Fa "vm_map_t map" "vm_object_t object" "vm_ooffset_t offset" .Fa "vm_offset_t *addr" "vm_size_t length" "int find_space" .Fa "vm_prot_t prot" "vm_prot_t max" "int cow" .Fc .Sh DESCRIPTION The .Fn vm_map_find function attempts to find a free region in the target .Fa map , with the given .Fa length , and will also optionally create a mapping of .Fa object .

p The arguments .Fa offset , .Fa prot , .Fa max , and .Fa cow are passed unchanged to .Xr vm_map_insert 9 when creating the mapping, if and only if a free region is found.

p If .Fa object is

f non- Dv NULL , the reference count on the object must be incremented by the caller before calling this function to account for the new entry.

p If .Fa find_space is either .Dv VMFS_ALIGNED_SPACE or .Dv VMFS_ANY_SPACE , the function will call .Xr vm_map_findspace 9 to discover a free region. Moreover, if .Fa find_space is .Dv VMFS_ALIGNED_SPACE , the address of the free region will be optimized for the use of superpages. Otherwise, if .Fa find_space is .Dv VMFS_NO_SPACE , .Xr vm_map_insert 9 is called with the given address, .Fa addr . .Sh IMPLEMENTATION NOTES This function acquires a lock on .Fa map by calling .Xr vm_map_lock 9 , and holds it until the function returns.

p The search for a free region is defined to be first-fit, from the address .Fa addr onwards. .Sh RETURN VALUES The .Fn vm_map_find function returns .Dv KERN_SUCCESS if the mapping was successfully created. If space could not be found or .Fa find_space was .Dv VMFS_NO_SPACE and the given address, .Fa addr , was already mapped, .Dv KERN_NO_SPACE will be returned. If the discovered range turned out to be bogus, .Dv KERN_INVALID_ADDRESS will be returned. .Sh SEE ALSO .Xr vm_map 9 , .Xr vm_map_findspace 9 , .Xr vm_map_insert 9 , .Xr vm_map_lock 9 .Sh AUTHORS This manual page was written by .An Bruce M Simpson Aq bms@spc.org .