linux-master/mm/ksm.c

89  *   write protected memory content, but each "dup" corresponds to a
532 static __always_inline bool is_stable_node_dup(struct ksm_stable_node *dup)
534 	return dup->head == STABLE_NODE_DUP_HEAD;
537 static inline void stable_node_chain_add_dup(struct ksm_stable_node *dup,
540 	VM_BUG_ON(is_stable_node_dup(dup));
541 	dup->head = STABLE_NODE_DUP_HEAD;
543 	hlist_add_head(&dup->hlist_dup, &chain->hlist);
547 static inline void __stable_node_dup_del(struct ksm_stable_node *dup)
549 	VM_BUG_ON(!is_stable_node_dup(dup));
550 	hlist_del(&dup->hlist_dup);
554 static inline void stable_node_dup_del(struct ksm_stable_node *dup)
556 	VM_BUG_ON(is_stable_node_chain(dup));
557 	if (is_stable_node_dup(dup))
558 		__stable_node_dup_del(dup);
560 		rb_erase(&dup->node, root_stable_tree + NUMA(dup->nid));
562 	dup->head = NULL;
810 static struct ksm_stable_node *alloc_stable_node_chain(struct ksm_stable_node *dup,
814 	VM_BUG_ON(is_stable_node_chain(dup));
829 		rb_replace_node(&dup->node, &chain->node, root);
834 		 * dup stable_nodes in the chain->hlist point to pages
838 		stable_node_chain_add_dup(dup, chain);
1061  * page and upping mmap_lock.  Nor does it fit with the way we skip dup'ing
1149 	struct ksm_stable_node *dup;
1160 	hlist_for_each_entry_safe(dup, hlist_safe,
1162 		VM_BUG_ON(!is_stable_node_dup(dup));
1163 		if (remove_stable_node(dup))
1625 	struct ksm_stable_node *dup, *found = NULL, *stable_node = *_stable_node;
1639 	hlist_for_each_entry_safe(dup, hlist_safe,
1648 		 * (that's why we do a _safe walk). The "dup"
1652 		_tree_page = get_ksm_page(dup, GET_KSM_PAGE_NOLOCK);
1656 		if (is_page_sharing_candidate(dup)) {
1658 			    dup->rmap_hlist_len > found_rmap_hlist_len) {
1661 				found = dup;
1665 				/* skip put_page for found dup */
1715 			 * If the found stable_node dup can accept one
1726 			 * the position of the found dup in the chain,
1853 		 * stable_node dup was found in it). In such case the
1910 				 * into a stable node dup. If the mapcount is
1985 	 * stable_node_dup is the dup to replace.
2036 	 * stable_node_dup is the dup to replace.
2047 	 * Add this stable_node dup that was
3273 	struct ksm_stable_node *dup;
3282 	hlist_for_each_entry_safe(dup, hlist_safe,
3284 		VM_BUG_ON(!is_stable_node_dup(dup));
3285 		stable_node_dup_remove_range(dup, start_pfn, end_pfn);