Commit 4acef569 authored by Kinsey Ho's avatar Kinsey Ho Committed by Andrew Morton
Browse files

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: default avatarKinsey 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent cc25bbe1

mm/vmscan.c

+10 −10
Original line number Diff line number Diff line
@@ -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 */