mm/mglru: improve swappiness handling
The reclaimable number of anon pages used to set initial reclaim priority
is only based on get_swappiness(). Use can_reclaim_anon_pages() to
include NUMA node demotion.
Also move the swappiness handling of when !__GFP_IO in
try_to_shrink_lruvec() into isolate_folios().
Link: https://lkml.kernel.org/r/20240214060538.3524462-6-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Donet Tom <donettom@linux.vnet.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 577e7f9b..198d623 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4289,7 +4289,7 @@ static bool isolate_folio(struct lruvec *lruvec, struct folio *folio, struct sca
{
bool success;
- /* swapping inhibited */
+ /* swap constrained */
if (!(sc->gfp_mask & __GFP_IO) &&
(folio_test_dirty(folio) ||
(folio_test_anon(folio) && !folio_test_swapcache(folio))))
@@ -4458,9 +4458,12 @@ static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int sw
DEFINE_MIN_SEQ(lruvec);
/*
- * Try to make the obvious choice first. When anon and file are both
- * available from the same generation, interpret swappiness 1 as file
- * first and 200 as anon first.
+ * Try to make the obvious choice first, and if anon and file are both
+ * available from the same generation,
+ * 1. Interpret swappiness 1 as file first and MAX_SWAPPINESS as anon
+ * first.
+ * 2. If !__GFP_IO, file first since clean pagecache is more likely to
+ * exist than clean swapcache.
*/
if (!swappiness)
type = LRU_GEN_FILE;
@@ -4470,6 +4473,8 @@ static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int sw
type = LRU_GEN_FILE;
else if (swappiness == 200)
type = LRU_GEN_ANON;
+ else if (!(sc->gfp_mask & __GFP_IO))
+ type = LRU_GEN_FILE;
else
type = get_type_to_scan(lruvec, swappiness, &tier);
@@ -4713,10 +4718,6 @@ static bool try_to_shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
unsigned long scanned = 0;
int swappiness = get_swappiness(lruvec, sc);
- /* clean file folios are more likely to exist */
- if (swappiness && !(sc->gfp_mask & __GFP_IO))
- swappiness = 1;
-
while (true) {
int delta;
@@ -4879,7 +4880,6 @@ static void set_initial_priority(struct pglist_data *pgdat, struct scan_control
{
int priority;
unsigned long reclaimable;
- struct lruvec *lruvec = mem_cgroup_lruvec(NULL, pgdat);
if (sc->priority != DEF_PRIORITY || sc->nr_to_reclaim < MIN_LRU_BATCH)
return;
@@ -4889,7 +4889,7 @@ static void set_initial_priority(struct pglist_data *pgdat, struct scan_control
* where reclaimed_to_scanned_ratio = inactive / total.
*/
reclaimable = node_page_state(pgdat, NR_INACTIVE_FILE);
- if (get_swappiness(lruvec, sc))
+ if (can_reclaim_anon_pages(NULL, pgdat->node_id, sc))
reclaimable += node_page_state(pgdat, NR_INACTIVE_ANON);
/* round down reclaimable and round up sc->nr_to_reclaim */
