VM_MAP_FIND(9) MidnightBSD Kernel Developer’s Manual VM_MAP_FIND(9)


vm_map_find — find a free region within a map, and optionally map a vm_object


#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_map.h>


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);


The vm_map_find() function attempts to find a free region in the target map, with the given length, and will also optionally create a mapping of object.

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

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

If find_space is TRUE, the function will call vm_map_findspace(9) to discover a free region.


This function acquires a lock on map by calling vm_map_lock(9), and holds it until the function returns.

The search for a free region is defined to be first-fit, from the address addr onwards.


The vm_map_find() function returns KERN_SUCCESS if space for the mapping could be found and the mapping was successfully created. If space could not be found in the map, KERN_NO_SPACE will be returned. If the discovered range turned out to be bogus, KERN_INVALID_ADDRESS will be returned.


vm_map(9), vm_map_findspace(9), vm_map_insert(9), vm_map_lock(9)


This manual page was written by Bruce M Simpson 〈bms@spc.org〉.

MidnightBSD 0.3 July 19, 2003 MidnightBSD 0.3