Function vm_map_entry_delete

freebsd/vm/vm_map.c:3852–3923

* vm_map_entry_delete: [ internal use only ] * * Deallocate the given entry from the target map. */

 *	Deallocate the given entry from the target map.
 */
static void
vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
{
	vm_object_t object;
	vm_pindex_t offidxstart, offidxend, size1;
	vm_size_t size;

	vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE);
	object = entry->object.vm_object;

	if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
		MPASS(entry->cred == NULL);
		MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
		MPASS(object == NULL);
		vm_map_entry_deallocate(entry, map->system_map);
		return;
	}

	size = entry->end - entry->start;
	map->size -= size;

	if (entry->cred != NULL) {
		swap_release_by_cred(size, entry->cred);
		crfree(entry->cred);
	}

	if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) {
		entry->object.vm_object = NULL;
	} else if ((object->flags & OBJ_ANON) != 0 ||
	    object == kernel_object) {
		KASSERT(entry->cred == NULL || object->cred == NULL ||
		    (entry->eflags & MAP_ENTRY_NEEDS_COPY),
		    ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
		offidxstart = OFF_TO_IDX(entry->offset);
		offidxend = offidxstart + atop(size);
		VM_OBJECT_WLOCK(object);
		if (object->ref_count != 1 &&
		    ((object->flags & OBJ_ONEMAPPING) != 0 ||
		    object == kernel_object)) {
			vm_object_collapse(object);

			/*
			 * The option OBJPR_NOTMAPPED can be passed here
			 * because vm_map_delete() already performed
			 * pmap_remove() on the only mapping to this range
			 * of pages. 
			 */
			vm_object_page_remove(object, offidxstart, offidxend,
			    OBJPR_NOTMAPPED);
			if (offidxend >= object->size &&
			    offidxstart < object->size) {
				size1 = object->size;
				object->size = offidxstart;
				if (object->cred != NULL) {
					size1 -= object->size;
					KASSERT(object->charge >= ptoa(size1),
					    ("object %p charge < 0", object));
					swap_release_by_cred(ptoa(size1),