linux-master/mm/ksm.c

152  * @hlist_dup: linked into the stable_node->hlist with a stable_node chain
527 static __always_inline bool is_stable_node_chain(struct ksm_stable_node *chain)
529 	return chain->rmap_hlist_len == STABLE_NODE_CHAIN;
538 					     struct ksm_stable_node *chain)
542 	VM_BUG_ON(!is_stable_node_chain(chain));
543 	hlist_add_head(&dup->hlist_dup, &chain->hlist);
813 	struct ksm_stable_node *chain = alloc_stable_node();
815 	if (likely(chain)) {
816 		INIT_HLIST_HEAD(&chain->hlist);
817 		chain->chain_prune_time = jiffies;
818 		chain->rmap_hlist_len = STABLE_NODE_CHAIN;
820 		chain->nid = NUMA_NO_NODE; /* debug */
825 		 * Put the stable node chain in the first dimension of
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);
840 	return chain;
843 static inline void free_stable_node_chain(struct ksm_stable_node *chain,
846 	rb_erase(&chain->node, root);
847 	free_stable_node(chain);
1676 		 * nr is counting all dups in the chain only if
1692 			 * deduplication limit so drop the chain.
1701 			 * to be equal to stable_node_dup if the chain
1718 			 * the chain, put it there so next search will
1726 			 * the position of the found dup in the chain,
1727 			 * but the total number of dups in the chain.
1757  * stable_node_dup if the chain is collapsed (in which case
1758  * *_stable_node will be equal to *_stable_node_dup like if the chain
1795 static __always_inline struct page *chain(struct ksm_stable_node **s_n_d,
1852 		 * order to collapse the stable_node chain if a single
1857 		 * stable_node_dup like if the chain never existed.
1862 			 * this stable_node chain, or this chain was
1873 			 * this stable_node chain to let the tree walk
1875 			 * stable_node dups in a stable_node chain
1912 				 * without adding it to the chain.
1920 				 * If the stable_node is a chain and
1980 	 * If stable_node was a chain and chain_prune collapsed it,
1982 	 * stable_node. A collapse of the chain is indistinguishable
1983 	 * from the case there was no chain in the stable
1984 	 * rbtree. Otherwise stable_node is the chain and
1990 		/* there is no chain */
2031 	 * If stable_node was a chain and chain_prune collapsed it,
2033 	 * stable_node. A collapse of the chain is indistinguishable
2034 	 * from the case there was no chain in the stable
2035 	 * rbtree. Otherwise stable_node is the chain and
2040 		/* chain is missing so create it */
2048 	 * migrated to the stable_node chain
2091 		tree_page = chain(&stable_node_dup, stable_node, root);
2095 			 * this stable_node chain, or this chain was
2106 			 * this stable_node chain to let the tree walk
2108 			 * stable_node dups in a stable_node chain
2159 			/* chain is missing so create it */