177  * slot of the evicted page.  This is called a shadow entry.
179  * On cache misses for which there are shadow entries, an eligible
210 static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,  in unpack_shadow()  argument
213 	unsigned long entry = xa_to_value(shadow);  in unpack_shadow()
261  * Tests if the shadow entry is for a folio that was recently evicted.
262  * Fills in @lruvec, @token, @workingset with the values unpacked from shadow.
264 static bool lru_gen_test_recent(void *shadow, struct lruvec **lruvec,  in lru_gen_test_recent()  argument
272 	unpack_shadow(shadow, &memcg_id, &pgdat, token, workingset);  in lru_gen_test_recent()
283 static void lru_gen_refault(struct folio *folio, void *shadow)  in lru_gen_refault()  argument
296 	recent = lru_gen_test_recent(shadow, &lruvec, &token, &workingset);  in lru_gen_refault()
333 static bool lru_gen_test_recent(void *shadow, struct lruvec **lruvec,  in lru_gen_test_recent()  argument
339 static void lru_gen_refault(struct folio *folio, void *shadow)  in lru_gen_refault()  argument
378  * Return: a shadow entry to be stored in @folio->mapping->i_pages in place
407  * workingset_test_recent - tests if the shadow entry is for a folio that was
409  * shadow.
410  * @shadow: the shadow entry to be tested.
412  * @workingset: where the workingset value unpacked from shadow should
416  * Return: true if the shadow is for a recently evicted folio; false otherwise.
418 bool workingset_test_recent(void *shadow, bool file, bool *workingset,  in workingset_test_recent()  argument
434 		recent = lru_gen_test_recent(shadow, &eviction_lruvec, &eviction, workingset);  in workingset_test_recent()
440 	unpack_shadow(shadow, &memcgid, &pgdat, &eviction, workingset);  in workingset_test_recent()
487 	 * special case: usually, shadow entries have a short lifetime  in workingset_test_recent()
490 	 * nonresident_age to lap a shadow entry in the field, which  in workingset_test_recent()
528  * @shadow: Shadow entry of the evicted folio.
534 void workingset_refault(struct folio *folio, void *shadow)  in workingset_refault()  argument
546 		lru_gen_refault(folio, shadow);  in workingset_refault()
566 	if (!workingset_test_recent(shadow, file, &workingset, true))  in workingset_refault()
600  * Shadow entries reflect the share of the working set that does not
606  * create excessive amounts of shadow nodes.  To keep a lid on this,
607  * track shadow nodes and reclaim them when they grow way past the
619 	 * Track non-empty nodes that contain only shadow entries;  in workingset_update_node()
655 	 * containing shadow entries. We don't need to keep more  in count_shadow_nodes()
656 	 * shadow entries than possible pages on the active list,  in count_shadow_nodes()
663 	 * Nodes might be sparsely populated, with only one shadow  in count_shadow_nodes()
665 	 * node for every eligible shadow entry, so compromise on a  in count_shadow_nodes()
670 	 * each, this will reclaim shadow entries when they consume  in count_shadow_nodes()
710 	 * the shadow node LRU under the i_pages lock and the  in shadow_lru_isolate()
745 	 * The nodes should only contain one or more shadow entries,  in shadow_lru_isolate()
807 						    "mm-shadow");  in workingset_init()