[PATCH v2 01/12] mm/mglru: consolidate common code for retrieving evitable size

From: Kairui Song via B4 Relay

Date: Sat Mar 28 2026 - 15:52:58 EST


From: Kairui Song <kasong@xxxxxxxxxxx>

Merge commonly used code for counting evictable folios in a lruvec.

No behavior change.

Return unsigned long instead of long as suggested [ Axel Rasmussen ]

Acked-by: Yuanchu Xie <yuanchu@xxxxxxxxxx>
Reviewed-by: Barry Song <baohua@xxxxxxxxxx>
Reviewed-by: Chen Ridong <chenridong@xxxxxxxxxxxxxxx>
Reviewed-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
---
mm/vmscan.c | 36 ++++++++++++++----------------------
1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5a8c8fcccbfc..adc07501a137 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4084,27 +4084,33 @@ static void set_initial_priority(struct pglist_data *pgdat, struct scan_control
sc->priority = clamp(priority, DEF_PRIORITY / 2, DEF_PRIORITY);
}

-static bool lruvec_is_sizable(struct lruvec *lruvec, struct scan_control *sc)
+static unsigned long lruvec_evictable_size(struct lruvec *lruvec, int swappiness)
{
int gen, type, zone;
- unsigned long total = 0;
- int swappiness = get_swappiness(lruvec, sc);
+ unsigned long seq, total = 0;
struct lru_gen_folio *lrugen = &lruvec->lrugen;
- struct mem_cgroup *memcg = lruvec_memcg(lruvec);
DEFINE_MAX_SEQ(lruvec);
DEFINE_MIN_SEQ(lruvec);

for_each_evictable_type(type, swappiness) {
- unsigned long seq;
-
for (seq = min_seq[type]; seq <= max_seq; seq++) {
gen = lru_gen_from_seq(seq);
-
for (zone = 0; zone < MAX_NR_ZONES; zone++)
total += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L);
}
}

+ return total;
+}
+
+static bool lruvec_is_sizable(struct lruvec *lruvec, struct scan_control *sc)
+{
+ unsigned long total;
+ int swappiness = get_swappiness(lruvec, sc);
+ struct mem_cgroup *memcg = lruvec_memcg(lruvec);
+
+ total = lruvec_evictable_size(lruvec, swappiness);
+
/* whether the size is big enough to be helpful */
return mem_cgroup_online(memcg) ? (total >> sc->priority) : total;
}
@@ -4909,9 +4915,6 @@ static int evict_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq,
int swappiness, unsigned long *nr_to_scan)
{
- int gen, type, zone;
- unsigned long size = 0;
- struct lru_gen_folio *lrugen = &lruvec->lrugen;
DEFINE_MIN_SEQ(lruvec);

*nr_to_scan = 0;
@@ -4919,18 +4922,7 @@ static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq,
if (evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS > max_seq)
return true;

- for_each_evictable_type(type, swappiness) {
- unsigned long seq;
-
- for (seq = min_seq[type]; seq <= max_seq; seq++) {
- gen = lru_gen_from_seq(seq);
-
- for (zone = 0; zone < MAX_NR_ZONES; zone++)
- size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L);
- }
- }
-
- *nr_to_scan = size;
+ *nr_to_scan = lruvec_evictable_size(lruvec, swappiness);
/* better to run aging even though eviction is still possible */
return evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS == max_seq;
}

--
2.53.0