VM_MAP_FINDSPACE(9) BSD Kernel Developer's Manual VM_MAP_FINDSPACE(9)NAME
vm_map_findspace -- find a free region within a map
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_map.h>
int
vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, vm_offset_t *addr);
DESCRIPTION
The vm_map_findspace() function attempts to find a region with sufficient space in the map for an object of size length at the address addr.
IMPLEMENTATION NOTES
It is the caller's responsibility to obtain a lock on the map using vm_map_lock(9) before calling this function.
This routine may call pmap_growkernel(9) to grow the kernel's address space, if and only if the mapping is being made within the kernel
address space, and if insufficient space remains in the kernel_map.
RETURN VALUES
The vm_map_findspace() function returns the value 0 if successful, and *addr will contain the first virtual address in the found region; oth-
erwise, the value 1 is returned.
SEE ALSO pmap_growkernel(9), vm_map(9), vm_map_entry_resize_free(9), vm_map_lock(9)AUTHORS
This manual page was written by Bruce M Simpson <bms@spc.org>.
BSD July 19, 2003 BSD
Check Out this Related Man Page
VM_MAP_FIND(9) BSD Kernel Developer's Manual VM_MAP_FIND(9)NAME
vm_map_find -- find a free region within a map, and optionally map a vm_object
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_map.h>
int
vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t *addr, vm_size_t length, int find_space, vm_prot_t prot,
vm_prot_t max, int cow);
DESCRIPTION
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 either VMFS_ALIGNED_SPACE or VMFS_ANY_SPACE, the function will call vm_map_findspace(9) to discover a free region. More-
over, if find_space is VMFS_ALIGNED_SPACE, the address of the free region will be optimized for the use of superpages. Otherwise, if
find_space is VMFS_NO_SPACE, vm_map_insert(9) is called with the given address, addr.
IMPLEMENTATION NOTES
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.
RETURN VALUES
The vm_map_find() function returns KERN_SUCCESS if the mapping was successfully created. If space could not be found or find_space was
VMFS_NO_SPACE and the given address, addr, was already mapped, KERN_NO_SPACE will be returned. If the discovered range turned out to be
bogus, KERN_INVALID_ADDRESS will be returned.
SEE ALSO vm_map(9), vm_map_findspace(9), vm_map_insert(9), vm_map_lock(9)AUTHORS
This manual page was written by Bruce M Simpson <bms@spc.org>.
BSD May 10, 2008 BSD