57  * That's why some trick involving shared.vm_set.parent is used for identifying
62  * vma->shared.vm_set.parent != NULL    ==> a tree node
63  *      vma->shared.vm_set.head != NULL ==> list of others mapping same range
64  *      vma->shared.vm_set.head == NULL ==> no others map the same range
66  * vma->shared.vm_set.parent == NULL
67  * 	vma->shared.vm_set.head != NULL ==> list head of vmas mapping same range
68  * 	vma->shared.vm_set.head == NULL ==> a list node
82 	vma->shared.vm_set.head = NULL;  in vma_prio_tree_add()
83 	vma->shared.vm_set.parent = NULL;  in vma_prio_tree_add()
85 	if (!old->shared.vm_set.parent)  in vma_prio_tree_add()
86 		list_add(&vma->shared.vm_set.list,  in vma_prio_tree_add()
87 				&old->shared.vm_set.list);  in vma_prio_tree_add()
88 	else if (old->shared.vm_set.head)  in vma_prio_tree_add()
89 		list_add_tail(&vma->shared.vm_set.list,  in vma_prio_tree_add()
90 				&old->shared.vm_set.head->shared.vm_set.list);  in vma_prio_tree_add()
92 		INIT_LIST_HEAD(&vma->shared.vm_set.list);  in vma_prio_tree_add()
93 		vma->shared.vm_set.head = old;  in vma_prio_tree_add()
94 		old->shared.vm_set.head = vma;  in vma_prio_tree_add()
104 	vma->shared.vm_set.head = NULL;  in vma_prio_tree_insert()
106 	ptr = raw_prio_tree_insert(root, &vma->shared.prio_tree_node);  in vma_prio_tree_insert()
107 	if (ptr != (struct prio_tree_node *) &vma->shared.prio_tree_node) {  in vma_prio_tree_insert()
109 					shared.prio_tree_node);  in vma_prio_tree_insert()
119 	if (!vma->shared.vm_set.head) {  in vma_prio_tree_remove()
120 		if (!vma->shared.vm_set.parent)  in vma_prio_tree_remove()
121 			list_del_init(&vma->shared.vm_set.list);  in vma_prio_tree_remove()
123 			raw_prio_tree_remove(root, &vma->shared.prio_tree_node);  in vma_prio_tree_remove()
126 		BUG_ON(vma->shared.vm_set.head->shared.vm_set.head != vma);  in vma_prio_tree_remove()
127 		if (vma->shared.vm_set.parent) {  in vma_prio_tree_remove()
128 			head = vma->shared.vm_set.head;  in vma_prio_tree_remove()
129 			if (!list_empty(&head->shared.vm_set.list)) {  in vma_prio_tree_remove()
131 					head->shared.vm_set.list.next,  in vma_prio_tree_remove()
133 					shared.vm_set.list);  in vma_prio_tree_remove()
134 				list_del_init(&head->shared.vm_set.list);  in vma_prio_tree_remove()
138 			raw_prio_tree_replace(root, &vma->shared.prio_tree_node,  in vma_prio_tree_remove()
139 					&head->shared.prio_tree_node);  in vma_prio_tree_remove()
140 			head->shared.vm_set.head = new_head;  in vma_prio_tree_remove()
142 				new_head->shared.vm_set.head = head;  in vma_prio_tree_remove()
145 			node = vma->shared.vm_set.head;  in vma_prio_tree_remove()
146 			if (!list_empty(&vma->shared.vm_set.list)) {  in vma_prio_tree_remove()
148 					vma->shared.vm_set.list.next,  in vma_prio_tree_remove()
150 					shared.vm_set.list);  in vma_prio_tree_remove()
151 				list_del_init(&vma->shared.vm_set.list);  in vma_prio_tree_remove()
152 				node->shared.vm_set.head = new_head;  in vma_prio_tree_remove()
153 				new_head->shared.vm_set.head = node;  in vma_prio_tree_remove()
155 				node->shared.vm_set.head = NULL;  in vma_prio_tree_remove()
178 						shared.prio_tree_node);  in vma_prio_tree_next()
179 			prefetch(next->shared.vm_set.head);  in vma_prio_tree_next()
185 	if (vma->shared.vm_set.parent) {  in vma_prio_tree_next()
186 		if (vma->shared.vm_set.head) {  in vma_prio_tree_next()
187 			next = vma->shared.vm_set.head;  in vma_prio_tree_next()
188 			prefetch(next->shared.vm_set.list.next);  in vma_prio_tree_next()
192 		next = list_entry(vma->shared.vm_set.list.next,  in vma_prio_tree_next()
193 				struct vm_area_struct, shared.vm_set.list);  in vma_prio_tree_next()
194 		if (!next->shared.vm_set.head) {  in vma_prio_tree_next()
195 			prefetch(next->shared.vm_set.list.next);  in vma_prio_tree_next()
203 					shared.prio_tree_node);  in vma_prio_tree_next()
204 		prefetch(next->shared.vm_set.head);  in vma_prio_tree_next()