[PATCH] mm: add lazyfree folio to lru tail

From: gaoxu
Date: Thu Aug 15 2024 - 08:52:55 EST


Replace lruvec_add_folio with lruvec_add_folio_tail in the lru_lazyfree_fn:
1. The lazy-free folio is added to the LRU_INACTIVE_FILE list. If it's
moved to the LRU tail, it allows for faster release lazy-free folio and
reduces the impact on file refault.
2. When mglru is enabled, the lazy-free folio is reclaimabled and should be
added using lru_gen_add_folio(lruvec, folio, true) instead of
lru_gen_add_folio(lruvec, folio, false) for adding to gen.

With the change in place, workingset_refault_file is reduced by 33% in the
continuous startup testing of the applications in the Android system.

Signed-off-by: gao xu <gaoxu2@xxxxxxxxxxx>
---
mm/swap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/swap.c b/mm/swap.c
index 67786cb77..ed49643ec 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -635,7 +635,7 @@ static void lru_lazyfree_fn(struct lruvec *lruvec, struct folio *folio)
* anonymous folios
*/
folio_clear_swapbacked(folio);
- lruvec_add_folio(lruvec, folio);
+ lruvec_add_folio_tail(lruvec, folio);

__count_vm_events(PGLAZYFREE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE,
--
2.17.1