590 static inline void free_stable_node(struct ksm_stable_node *stable_node)  in free_stable_node()  argument
592 	VM_BUG_ON(stable_node->rmap_hlist_len &&  in free_stable_node()
593 		  !is_stable_node_chain(stable_node));  in free_stable_node()
594 	kmem_cache_free(stable_node_cache, stable_node);  in free_stable_node()
817 static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node)  in remove_node_from_stable_tree()  argument
822 	BUG_ON(stable_node->rmap_hlist_len < 0);  in remove_node_from_stable_tree()
824 	hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {  in remove_node_from_stable_tree()
827 			trace_ksm_remove_rmap_item(stable_node->kpfn, rmap_item, rmap_item->mm);  in remove_node_from_stable_tree()
834 		VM_BUG_ON(stable_node->rmap_hlist_len <= 0);  in remove_node_from_stable_tree()
835 		stable_node->rmap_hlist_len--;  in remove_node_from_stable_tree()
851 	trace_ksm_remove_ksm_page(stable_node->kpfn);  in remove_node_from_stable_tree()
852 	if (stable_node->head == &migrate_nodes)  in remove_node_from_stable_tree()
853 		list_del(&stable_node->list);  in remove_node_from_stable_tree()
855 		stable_node_dup_del(stable_node);  in remove_node_from_stable_tree()
856 	free_stable_node(stable_node);  in remove_node_from_stable_tree()
884 static struct folio *ksm_get_folio(struct ksm_stable_node *stable_node,  in ksm_get_folio()  argument
891 	expected_mapping = (void *)((unsigned long)stable_node |  in ksm_get_folio()
894 	kpfn = READ_ONCE(stable_node->kpfn); /* Address dependency. */  in ksm_get_folio()
954 	if (READ_ONCE(stable_node->kpfn) != kpfn)  in ksm_get_folio()
956 	remove_node_from_stable_tree(stable_node);  in ksm_get_folio()
967 		struct ksm_stable_node *stable_node;  in remove_rmap_item_from_tree()  local
970 		stable_node = rmap_item->head;  in remove_rmap_item_from_tree()
971 		folio = ksm_get_folio(stable_node, KSM_GET_FOLIO_LOCK);  in remove_rmap_item_from_tree()
979 		if (!hlist_empty(&stable_node->hlist))  in remove_rmap_item_from_tree()
986 		VM_BUG_ON(stable_node->rmap_hlist_len <= 0);  in remove_rmap_item_from_tree()
987 		stable_node->rmap_hlist_len--;  in remove_rmap_item_from_tree()
1066 					 struct ksm_stable_node *stable_node)  in folio_set_stable_node()  argument
1069 	folio->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);  in folio_set_stable_node()
1076 static int remove_stable_node(struct ksm_stable_node *stable_node)  in remove_stable_node()  argument
1081 	folio = ksm_get_folio(stable_node, KSM_GET_FOLIO_LOCK);  in remove_stable_node()
1105 		remove_node_from_stable_tree(stable_node);  in remove_stable_node()
1114 static int remove_stable_node_chain(struct ksm_stable_node *stable_node,  in remove_stable_node_chain()  argument
1120 	if (!is_stable_node_chain(stable_node)) {  in remove_stable_node_chain()
1121 		VM_BUG_ON(is_stable_node_dup(stable_node));  in remove_stable_node_chain()
1122 		if (remove_stable_node(stable_node))  in remove_stable_node_chain()
1129 				  &stable_node->hlist, hlist_dup) {  in remove_stable_node_chain()
1134 	BUG_ON(!hlist_empty(&stable_node->hlist));  in remove_stable_node_chain()
1135 	free_stable_node_chain(stable_node, root);  in remove_stable_node_chain()
1141 	struct ksm_stable_node *stable_node, *next;  in remove_all_stable_nodes()  local
1147 			stable_node = rb_entry(root_stable_tree[nid].rb_node,  in remove_all_stable_nodes()
1149 			if (remove_stable_node_chain(stable_node,  in remove_all_stable_nodes()
1157 	list_for_each_entry_safe(stable_node, next, &migrate_nodes, list) {  in remove_all_stable_nodes()
1158 		if (remove_stable_node(stable_node))  in remove_all_stable_nodes()
1614 bool __is_page_sharing_candidate(struct ksm_stable_node *stable_node, int offset)  in __is_page_sharing_candidate()  argument
1616 	VM_BUG_ON(stable_node->rmap_hlist_len < 0);  in __is_page_sharing_candidate()
1623 	return stable_node->rmap_hlist_len &&  in __is_page_sharing_candidate()
1624 		stable_node->rmap_hlist_len + offset < ksm_max_page_sharing;  in __is_page_sharing_candidate()
1628 bool is_page_sharing_candidate(struct ksm_stable_node *stable_node)  in is_page_sharing_candidate()  argument
1630 	return __is_page_sharing_candidate(stable_node, 0);  in is_page_sharing_candidate()
1638 	struct ksm_stable_node *dup, *found = NULL, *stable_node = *_stable_node;  in stable_node_dup()  local
1644 	    time_before(jiffies, stable_node->chain_prune_time +  in stable_node_dup()
1649 		stable_node->chain_prune_time = jiffies;  in stable_node_dup()
1652 				  &stable_node->hlist, hlist_dup) {  in stable_node_dup()
1686 		if (hlist_is_singular_node(&found->hlist_dup, &stable_node->hlist)) {  in stable_node_dup()
1693 			BUG_ON(stable_node->hlist.first->next);  in stable_node_dup()
1699 			rb_replace_node(&stable_node->node, &found->node,  in stable_node_dup()
1701 			free_stable_node(stable_node);  in stable_node_dup()
1716 			stable_node = NULL;  in stable_node_dup()
1717 		} else if (stable_node->hlist.first != &found->hlist_dup &&  in stable_node_dup()
1736 				       &stable_node->hlist);  in stable_node_dup()
1740 		free_stable_node_chain(stable_node, root);  in stable_node_dup()
1766 	struct ksm_stable_node *stable_node = *_stable_node;  in __stable_node_chain()  local
1768 	if (!is_stable_node_chain(stable_node)) {  in __stable_node_chain()
1769 		*_stable_node_dup = stable_node;  in __stable_node_chain()
1770 		return ksm_get_folio(stable_node, KSM_GET_FOLIO_NOLOCK);  in __stable_node_chain()
1805 	struct ksm_stable_node *stable_node, *stable_node_dup;  in stable_tree_search()  local
1828 		stable_node = rb_entry(*new, struct ksm_stable_node, node);  in stable_tree_search()
1829 		tree_folio = chain_prune(&stable_node_dup, &stable_node, root);  in stable_tree_search()
1936 	if (stable_node_dup == stable_node) {  in stable_tree_search()
1956 		VM_BUG_ON(!is_stable_node_chain(stable_node));  in stable_tree_search()
1962 			stable_node_chain_add_dup(page_node, stable_node);  in stable_tree_search()
1984 	if (stable_node_dup == stable_node) {  in stable_tree_search()
1987 		stable_node = alloc_stable_node_chain(stable_node_dup,  in stable_tree_search()
1989 		if (!stable_node)  in stable_tree_search()
2002 	stable_node_chain_add_dup(page_node, stable_node);  in stable_tree_search()
2020 	struct ksm_stable_node *stable_node, *stable_node_dup;  in stable_tree_insert()  local
2035 		stable_node = rb_entry(*new, struct ksm_stable_node, node);  in stable_tree_insert()
2036 		tree_folio = chain(&stable_node_dup, &stable_node, root);  in stable_tree_insert()
2076 		if (!is_stable_node_chain(stable_node)) {  in stable_tree_insert()
2077 			struct ksm_stable_node *orig = stable_node;  in stable_tree_insert()
2079 			stable_node = alloc_stable_node_chain(orig, root);  in stable_tree_insert()
2080 			if (!stable_node) {  in stable_tree_insert()
2085 		stable_node_chain_add_dup(stable_node_dup, stable_node);  in stable_tree_insert()
2180 			       struct ksm_stable_node *stable_node,  in stable_tree_append()  argument
2193 	BUG_ON(stable_node->rmap_hlist_len < 0);  in stable_tree_append()
2195 	stable_node->rmap_hlist_len++;  in stable_tree_append()
2198 		WARN_ON_ONCE(stable_node->rmap_hlist_len >  in stable_tree_append()
2201 	rmap_item->head = stable_node;  in stable_tree_append()
2203 	hlist_add_head(&rmap_item->hlist, &stable_node->hlist);  in stable_tree_append()
2226 	struct ksm_stable_node *stable_node;  in cmp_and_merge_page()  local
2232 	stable_node = page_stable_node(page);  in cmp_and_merge_page()
2233 	if (stable_node) {  in cmp_and_merge_page()
2234 		if (stable_node->head != &migrate_nodes &&  in cmp_and_merge_page()
2235 		    get_kpfn_nid(READ_ONCE(stable_node->kpfn)) !=  in cmp_and_merge_page()
2236 		    NUMA(stable_node->nid)) {  in cmp_and_merge_page()
2237 			stable_node_dup_del(stable_node);  in cmp_and_merge_page()
2238 			stable_node->head = &migrate_nodes;  in cmp_and_merge_page()
2239 			list_add(&stable_node->list, stable_node->head);  in cmp_and_merge_page()
2241 		if (stable_node->head != &migrate_nodes &&  in cmp_and_merge_page()
2242 		    rmap_item->head == stable_node)  in cmp_and_merge_page()
2248 		if (!is_page_sharing_candidate(stable_node))  in cmp_and_merge_page()
2271 	if (&kfolio->page == page && rmap_item->head == stable_node) {  in cmp_and_merge_page()
2323 			stable_node = stable_tree_insert(kfolio);  in cmp_and_merge_page()
2324 			if (stable_node) {  in cmp_and_merge_page()
2325 				stable_tree_append(tree_rmap_item, stable_node,  in cmp_and_merge_page()
2327 				stable_tree_append(rmap_item, stable_node,  in cmp_and_merge_page()
2338 			if (!stable_node) {  in cmp_and_merge_page()
2494 			struct ksm_stable_node *stable_node, *next;  in scan_get_next_rmap_item()  local
2497 			list_for_each_entry_safe(stable_node, next,  in scan_get_next_rmap_item()
2499 				folio = ksm_get_folio(stable_node,  in scan_get_next_rmap_item()
3005 	struct ksm_stable_node *stable_node;  in rmap_walk_ksm()  local
3017 	stable_node = folio_stable_node(folio);  in rmap_walk_ksm()
3018 	if (!stable_node)  in rmap_walk_ksm()
3021 	hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {  in rmap_walk_ksm()
3080 	struct ksm_stable_node *stable_node;  in collect_procs_ksm()  local
3085 	stable_node = folio_stable_node(folio);  in collect_procs_ksm()
3086 	if (!stable_node)  in collect_procs_ksm()
3088 	hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {  in collect_procs_ksm()
3120 	struct ksm_stable_node *stable_node;  in folio_migrate_ksm()  local
3126 	stable_node = folio_stable_node(folio);  in folio_migrate_ksm()
3127 	if (stable_node) {  in folio_migrate_ksm()
3128 		VM_BUG_ON_FOLIO(stable_node->kpfn != folio_pfn(folio), folio);  in folio_migrate_ksm()
3129 		stable_node->kpfn = folio_pfn(newfolio);  in folio_migrate_ksm()
3153 static bool stable_node_dup_remove_range(struct ksm_stable_node *stable_node,  in stable_node_dup_remove_range()  argument
3157 	if (stable_node->kpfn >= start_pfn &&  in stable_node_dup_remove_range()
3158 	    stable_node->kpfn < end_pfn) {  in stable_node_dup_remove_range()
3163 		remove_node_from_stable_tree(stable_node);  in stable_node_dup_remove_range()
3169 static bool stable_node_chain_remove_range(struct ksm_stable_node *stable_node,  in stable_node_chain_remove_range()  argument
3177 	if (!is_stable_node_chain(stable_node)) {  in stable_node_chain_remove_range()
3178 		VM_BUG_ON(is_stable_node_dup(stable_node));  in stable_node_chain_remove_range()
3179 		return stable_node_dup_remove_range(stable_node, start_pfn,  in stable_node_chain_remove_range()
3184 				  &stable_node->hlist, hlist_dup) {  in stable_node_chain_remove_range()
3188 	if (hlist_empty(&stable_node->hlist)) {  in stable_node_chain_remove_range()
3189 		free_stable_node_chain(stable_node, root);  in stable_node_chain_remove_range()
3198 	struct ksm_stable_node *stable_node, *next;  in ksm_check_stable_tree()  local
3205 			stable_node = rb_entry(node, struct ksm_stable_node, node);  in ksm_check_stable_tree()
3206 			if (stable_node_chain_remove_range(stable_node,  in ksm_check_stable_tree()
3216 	list_for_each_entry_safe(stable_node, next, &migrate_nodes, list) {  in ksm_check_stable_tree()
3217 		if (stable_node->kpfn >= start_pfn &&  in ksm_check_stable_tree()
3218 		    stable_node->kpfn < end_pfn)  in ksm_check_stable_tree()
3219 			remove_node_from_stable_tree(stable_node);  in ksm_check_stable_tree()