The reclaim_folio_list uses a dummy reclaim_stat and is not being
used. To know the memory stat, add a new trace event. This is useful how
how many pages are not reclaimed or why.
This is an example.
mm_vmscan_reclaim_pages: nr_scanned=17 nr_reclaimed=17 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0
Currenlty reclaim_folio_list is only called by reclaim_pages, and
reclaim_pages is used by damon and madvise. In the latest Android,
reclaim_pages is also used by shmem to reclaim all pages in a
address_space.
Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
---
include/trace/events/vmscan.h | 41 +++++++++++++++++++++++++++++++++++
mm/vmscan.c | 40 +++++++++++++++++++++++++++++-----
2 files changed, 76 insertions(+), 5 deletions(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 1a488c30afa5..509110a12fa5 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -346,6 +346,47 @@ TRACE_EVENT(mm_vmscan_write_folio,
show_reclaim_flags(__entry->reclaim_flags))
);
+TRACE_EVENT(mm_vmscan_reclaim_pages,
+
+ TP_PROTO(unsigned long nr_scanned, unsigned long nr_reclaimed,
+ struct reclaim_stat *stat),
+
+ TP_ARGS(nr_scanned, nr_reclaimed, stat),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, nr_scanned)
+ __field(unsigned long, nr_reclaimed)
+ __field(unsigned long, nr_dirty)
+ __field(unsigned long, nr_writeback)
+ __field(unsigned long, nr_congested)
+ __field(unsigned long, nr_immediate)
+ __field(unsigned int, nr_activate0)
+ __field(unsigned int, nr_activate1)
+ __field(unsigned long, nr_ref_keep)
+ __field(unsigned long, nr_unmap_fail)
+ ),
+
+ TP_fast_assign(
+ __entry->nr_scanned = nr_scanned;
+ __entry->nr_reclaimed = nr_reclaimed;
+ __entry->nr_dirty = stat->nr_dirty;
+ __entry->nr_writeback = stat->nr_writeback;
+ __entry->nr_congested = stat->nr_congested;
+ __entry->nr_immediate = stat->nr_immediate;
+ __entry->nr_activate0 = stat->nr_activate[0];
+ __entry->nr_activate1 = stat->nr_activate[1];
+ __entry->nr_ref_keep = stat->nr_ref_keep;
+ __entry->nr_unmap_fail = stat->nr_unmap_fail;
+ ),
+
+ TP_printk("nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld",
+ __entry->nr_scanned, __entry->nr_reclaimed,
+ __entry->nr_dirty, __entry->nr_writeback,
+ __entry->nr_congested, __entry->nr_immediate,
+ __entry->nr_activate0, __entry->nr_activate1,
+ __entry->nr_ref_keep, __entry->nr_unmap_fail)
+);
+
TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
TP_PROTO(int nid,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 749cdc110c74..4776c42dfd2a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2126,9 +2126,9 @@ static void shrink_active_list(unsigned long nr_to_scan,
}
static unsigned int reclaim_folio_list(struct list_head *folio_list,
- struct pglist_data *pgdat)
+ struct pglist_data *pgdat,
+ struct reclaim_stat *stat)
{
- struct reclaim_stat dummy_stat;
unsigned int nr_reclaimed;
struct folio *folio;
struct scan_control sc = {
@@ -2139,7 +2139,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list,
.no_demotion = 1,
};
- nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true);
+ nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, stat, true);
while (!list_empty(folio_list)) {
folio = lru_to_folio(folio_list);
list_del(&folio->lru);
@@ -2149,16 +2149,40 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list,
return nr_reclaimed;
}
+static void reclaim_stat_add(struct reclaim_stat *stat_from,
+ struct reclaim_stat *stat_to)
+{
+ int type;
+
+ if (!trace_mm_vmscan_reclaim_pages_enabled())
+ return;
+
+ stat_to->nr_dirty += stat_from->nr_dirty;
+ stat_to->nr_unqueued_dirty += stat_from->nr_unqueued_dirty;
+ stat_to->nr_congested += stat_from->nr_congested;
+ stat_to->nr_writeback += stat_from->nr_writeback;
+ stat_to->nr_immediate += stat_from->nr_immediate;
+ stat_to->nr_pageout += stat_from->nr_pageout;
+ for (type = 0; type < ANON_AND_FILE; type++)
+ stat_to->nr_activate[type] += stat_from->nr_activate[type];
+ stat_to->nr_ref_keep += stat_from->nr_ref_keep;
+ stat_to->nr_unmap_fail += stat_from->nr_unmap_fail;
+ stat_to->nr_lazyfree_fail += stat_from->nr_lazyfree_fail;
+}
+
unsigned long reclaim_pages(struct list_head *folio_list)
{
int nid;
+ unsigned int nr_scanned = 0;
unsigned int nr_reclaimed = 0;
LIST_HEAD(node_folio_list);
unsigned int noreclaim_flag;
+ struct reclaim_stat stat_total, stat_one;
if (list_empty(folio_list))
return nr_reclaimed;
+ memset(&stat_total, 0, sizeof(stat_total));
noreclaim_flag = memalloc_noreclaim_save();
nid = folio_nid(lru_to_folio(folio_list));
@@ -2168,14 +2192,20 @@ unsigned long reclaim_pages(struct list_head *folio_list)
if (nid == folio_nid(folio)) {
folio_clear_active(folio);
list_move(&folio->lru, &node_folio_list);
+ nr_scanned += folio_nr_pages(folio);
continue;
}
- nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid));
+ nr_reclaimed += reclaim_folio_list(&node_folio_list,
+ NODE_DATA(nid), &stat_one);
+ reclaim_stat_add(&stat_one, &stat_total);
nid = folio_nid(lru_to_folio(folio_list));
} while (!list_empty(folio_list));
- nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid));
+ nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid),
+ &stat_one);
+ reclaim_stat_add(&stat_one, &stat_total);
+ trace_mm_vmscan_reclaim_pages(nr_scanned, nr_reclaimed, &stat_total);
memalloc_noreclaim_restore(noreclaim_flag);
--
2.25.1
