As the legacy lru provides, the mglru needs some trace events for
debugging. Let's reuse following legacy events for the mglru.
trace_mm_vmscan_lru_isolate
trace_mm_vmscan_lru_shrink_inactive
Here's an example
mm_vmscan_lru_isolate: classzone=2 order=0 nr_requested=4096 nr_scanned=64
nr_skipped=0 nr_taken=64 lru=inactive_file
mm_vmscan_lru_shrink_inactive: nid=0 nr_scanned=64 nr_reclaimed=63 nr_dirty=0
nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0
nr_activate_file=1 nr_ref_keep=0 nr_unmap_fail=0 priority=2
flags=RECLAIM_WB_FILE|RECLAIM_WB_ASYNC
Signed-off-by: Jaewon Kim <jaewon31....@samsung.com>
Acked-by: Yu Zhao <yuz...@google.com>
---
v5: reuse the legacy trace events
v4: wrap with #ifdef CONFIG_LRU_GEN
v3: change printk format
v2: use condition and make it aligned
v1: introduce trace events
---
mm/vmscan.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6f13394b112e..3f963f3616ea 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -5005,6 +5005,7 @@ static int scan_folios(struct lruvec *lruvec, struct
scan_control *sc,
int sorted = 0;
int scanned = 0;
int isolated = 0;
+ int skipped = 0;
int remaining = MAX_LRU_BATCH;
struct lru_gen_folio *lrugen = &lruvec->lrugen;
struct mem_cgroup *memcg = lruvec_memcg(lruvec);
@@ -5018,7 +5019,7 @@ static int scan_folios(struct lruvec *lruvec, struct
scan_control *sc,
for (i = MAX_NR_ZONES; i > 0; i--) {
LIST_HEAD(moved);
- int skipped = 0;
+ int skipped_zone = 0;
int zone = (sc->reclaim_idx + i) % MAX_NR_ZONES;
struct list_head *head = &lrugen->folios[gen][type][zone];
@@ -5040,16 +5041,17 @@ static int scan_folios(struct lruvec *lruvec, struct
scan_control *sc,
isolated += delta;
} else {
list_move(&folio->lru, &moved);
- skipped += delta;
+ skipped_zone += delta;
}
- if (!--remaining || max(isolated, skipped) >=
MIN_LRU_BATCH)
+ if (!--remaining || max(isolated, skipped_zone) >=
MIN_LRU_BATCH)
break;
}
- if (skipped) {
+ if (skipped_zone) {
list_splice(&moved, head);
- __count_zid_vm_events(PGSCAN_SKIP, zone, skipped);
+ __count_zid_vm_events(PGSCAN_SKIP, zone, skipped_zone);
+ skipped += skipped_zone;
}
if (!remaining || isolated >= MIN_LRU_BATCH)
@@ -5064,6 +5066,9 @@ static int scan_folios(struct lruvec *lruvec, struct
scan_control *sc,
__count_memcg_events(memcg, item, isolated);
__count_memcg_events(memcg, PGREFILL, sorted);
__count_vm_events(PGSCAN_ANON + type, isolated);
+ trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, MAX_LRU_BATCH,
+ scanned, skipped, isolated,
+ type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
/*
* There might not be eligible folios due to reclaim_idx. Check the
@@ -5194,6 +5199,9 @@ static int evict_folios(struct lruvec *lruvec, struct
scan_control *sc, int swap
retry:
reclaimed = shrink_folio_list(&list, pgdat, sc, &stat, false);
sc->nr_reclaimed += reclaimed;
+ trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
+ scanned, reclaimed, &stat, sc->priority,
+ type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
list_for_each_entry_safe_reverse(folio, next, &list, lru) {
if (!folio_evictable(folio)) {
--
2.17.1
