100 	/* Can active folios be deactivated as part of reclaim? */
110 	/* Can mapped folios be reclaimed? */
113 	/* Can folios be swapped as part of reclaim? */
147 	/* The file folios on the current node are dangerously low */
159 	/* The highest zone to isolate folios for reclaim from */
388  * This misses isolated folios which are not accounted for to save counters.
390  * not expected that isolated folios will be a dominating factor.
532 	 * If there are a lot of dirty/writeback folios then do not  in skip_throttle_noprogress()
533 	 * throttle as throttling will occur when the folios cycle  in skip_throttle_noprogress()
571 	 * writeback to a slow device to excessive referenced folios at the tail  in reclaim_throttle()
617  * Account for folios written if tasks are throttled waiting on dirty
618  * folios to clean. If enough folios have been cleaned since throttling
664 	 * the split out folios get added back to folio_list.  in writeout()
694 	 * We no longer attempt to writeback filesystem folios here, other  in pageout()
711 		 * Some data journaling orphaned folios can have  in pageout()
805 		 * only page cache folios found in these are zero pages  in __remove_mapping()
941 		 * All mapped folios start out with page table  in folio_check_references()
950 		 * Note: the mark is set for activated folios as well  in folio_check_references()
951 		 * so that recently deactivated but used folios are  in folio_check_references()
960 		 * Activate file-backed executable folios after first usage.  in folio_check_references()
968 	/* Reclaim if clean, defer dirty folios to writeback */  in folio_check_references()
982 	 * Anonymous folios are not handled by flushers and must be written  in folio_check_dirty_writeback()
984 	 * MADV_FREE anonymous folios are put into inactive file list too.  in folio_check_dirty_writeback()
1040  * Take folios on @demote_folios and attempt to demote them to another node.
1041  * Folios which are not demoted are left on @demote_folios.
1163 		 * folios if the tail of the LRU is all dirty unqueued folios.  in shrink_folio_list()
1173 		 * Treat this folio as congested if folios are cycling  in shrink_folio_list()
1174 		 * through the LRU so quickly that the folios marked  in shrink_folio_list()
1186 		 *    of folios under writeback and this folio has both  in shrink_folio_list()
1188 		 *    indicates that folios are being queued for I/O but  in shrink_folio_list()
1215 		 *    folios are in writeback and there is nothing else to  in shrink_folio_list()
1218 		 * In cases 1) and 2) we activate the folios to get them out of  in shrink_folio_list()
1219 		 * the way while we continue scanning for clean folios on the  in shrink_folio_list()
1312 					 * Split partially mapped folios right away.  in shrink_folio_list()
1412 			 * Only kswapd can writeback filesystem folios  in shrink_folio_list()
1416 			 * write folios when we've encountered many  in shrink_folio_list()
1417 			 * dirty folios, and when we've already scanned  in shrink_folio_list()
1418 			 * the rest of the LRU for clean folios and see  in shrink_folio_list()
1419 			 * the same dirty folios again (with the reclaim  in shrink_folio_list()
1509 		 * Rarely, folios can have buffers and no ->mapping.  in shrink_folio_list()
1510 		 * These are the folios which were not successfully  in shrink_folio_list()
1602 	/* Migrate folios selected for demotion */  in shrink_folio_list()
1606 	/* Folios that could not be demoted are still in @demote_folios */  in shrink_folio_list()
1608 		/* Folios which weren't demoted go back on @folio_list */  in shrink_folio_list()
1612 		 * goto retry to reclaim the undemoted folios in folio_list if  in shrink_folio_list()
1771 		 * Do not count skipped folios because that makes the function  in isolate_lru_folios()
1772 		 * return with no isolated folios if the LRU mostly contains  in isolate_lru_folios()
1773 		 * ineligible folios.  This causes the VM to not reclaim any  in isolate_lru_folios()
1774 		 * folios, triggering a premature OOM.  in isolate_lru_folios()
1806 	 * Splice any skipped folios to the start of the LRU list. Note that  in isolate_lru_folios()
1809 	 * scanning would soon rescan the same folios to skip and waste lots  in isolate_lru_folios()
1918  * move_folios_to_lru() moves folios from private @list to appropriate LRU list.
2069 	 * If dirty folios are scanned that are not queued for IO, it  in shrink_inactive_list()
2071 	 * happen when memory pressure pushes dirty folios to the end of  in shrink_inactive_list()
2074 	 * dirty folios grows not through writes but through memory  in shrink_inactive_list()
2083 		 * the kernel flusher here and later waiting on folios  in shrink_inactive_list()
2109  * shrink_active_list() moves folios from the active LRU to the inactive LRU.
2114  * If the folios are mostly unmapped, the processing is fast and it is
2116  * the folios are mapped, the processing is slow (folio_referenced()), so
2118  * this, so instead we remove the folios from the LRU while processing them.
2119  * It is safe to rely on the active flag against the non-LRU folios in here
2133 	LIST_HEAD(l_hold);	/* The folios which were snipped off */  in shrink_active_list()
2180 			 * Identify referenced, file-backed active folios and  in shrink_active_list()
2183 			 * memory under moderate memory pressure.  Anon folios  in shrink_active_list()
2185 			 * IO, plus JVM can create lots of anon VM_EXEC folios,  in shrink_active_list()
2201 	 * Move folios back to the lru list.  in shrink_active_list()
2303  * The inactive_ratio is the target ratio of ACTIVE to INACTIVE folios
2305  * of 3 means 3:1 or 25% of the folios are kept on the inactive list.
2552  * nr[0] = anon inactive folios to scan; nr[1] = anon active folios to scan
2553  * nr[2] = file inactive folios to scan; nr[3] = file active folios to scan
2566 	/* If we have no swap space, do not bother scanning anon folios. */  in get_scan_count()
3891 		struct list_head *head = &lrugen->folios[old_gen][type][zone];  in inc_min_seq()
3904 			list_move_tail(&folio->lru, &lrugen->folios[new_gen][type][zone]);  in inc_min_seq()
3942 				if (!list_empty(&lrugen->folios[gen][type][zone]))  in try_to_inc_min_seq()
4490 		list_move(&folio->lru, &lrugen->folios[gen][type][zone]);  in sort_folio()
4497 		list_move(&folio->lru, &lrugen->folios[gen][type][zone]);  in sort_folio()
4512 		list_move_tail(&folio->lru, &lrugen->folios[gen][type][zone]);  in sort_folio()
4527 		list_move(&folio->lru, &lrugen->folios[gen][type][zone]);  in sort_folio()
4593 		struct list_head *head = &lrugen->folios[gen][type][zone];  in scan_folios()
4644 	 * There might not be eligible folios due to reclaim_idx. Check the  in scan_folios()
4760 		/* retry folios that may have missed folio_rotate_reclaimable() */  in evict_folios()
4767 		/* don't add rejected folios to the oldest generation */  in evict_folios()
4859 	/* stop scanning this lruvec as it's low on cold folios */  in get_nr_to_scan()
5072 	 * Unmapped clean folios are already prioritized. Scanning for more of  in lru_gen_shrink_node()
5125 			if (!list_empty(&lrugen->folios[gen][type][zone]))  in state_is_valid()
5170 		struct list_head *head = &lruvec->lrugen.folios[gen][type][zone];  in drain_evictable()
5719 		INIT_LIST_HEAD(&lrugen->folios[gen][type][zone]);  in lru_gen_init_lruvec()
7850  * check_move_unevictable_folios - Move evictable folios to appropriate zone
7852  * @fbatch: Batch of lru folios to check.
7854  * Checks folios for evictability, if an evictable folio is in the unevictable
7856  * should be only used for lru folios.
7866 		struct folio *folio = fbatch->folios[i];  in check_move_unevictable_folios()