[PATCH] mm/memcontrol: add per-memcg pgpgin/pswpin counter

[Jingxiang Zeng <jingxiangzeng.cas@gmail.com>]

From: Jingxiang Zeng <linuszeng@tencent.com>

In proactive memory reclamation scenarios, it is necessary to
estimate the pswpin and pswpout metrics of the cgroup to
determine whether to continue reclaiming anonymous pages in
the current batch. This patch will collect these metrics and
expose them.

Signed-off-by: Jingxiang Zeng <linuszeng@tencent.com>
---
 mm/memcontrol-v1.c | 2 ++
 mm/memcontrol.c    | 2 ++
 mm/page_io.c       | 4 ++++
 3 files changed, 8 insertions(+)

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index b37c0d870816..44803cbea38a 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -2729,6 +2729,8 @@ static const char *const memcg1_stat_names[] = {
 static const unsigned int memcg1_events[] = {
 	PGPGIN,
 	PGPGOUT,
+	PSWPIN,
+	PSWPOUT,
 	PGFAULT,
 	PGMAJFAULT,
 };
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 087a8cb1a6d8..dde3d026f174 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -418,6 +418,8 @@ static const unsigned int memcg_vm_event_stat[] = {
 	PGPGIN,
 	PGPGOUT,
 #endif
+	PSWPIN,
+	PSWPOUT,
 	PGSCAN_KSWAPD,
 	PGSCAN_DIRECT,
 	PGSCAN_KHUGEPAGED,
diff --git a/mm/page_io.c b/mm/page_io.c
index b6f1519d63b0..4bc77d1c6bfa 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -310,6 +310,7 @@ static inline void count_swpout_vm_event(struct folio *folio)
 	}
 	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
 #endif
+	count_memcg_folio_events(folio, PSWPOUT, folio_nr_pages(folio));
 	count_vm_events(PSWPOUT, folio_nr_pages(folio));
 }
 
@@ -505,6 +506,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
 		for (p = 0; p < sio->pages; p++) {
 			struct folio *folio = page_folio(sio->bvec[p].bv_page);
 
+			count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 			folio_mark_uptodate(folio);
 			folio_unlock(folio);
 		}
@@ -588,6 +590,7 @@ static void swap_read_folio_bdev_sync(struct folio *folio,
 	 * attempt to access it in the page fault retry time check.
 	 */
 	get_task_struct(current);
+	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 	count_vm_event(PSWPIN);
 	submit_bio_wait(&bio);
 	__end_swap_bio_read(&bio);
@@ -603,6 +606,7 @@ static void swap_read_folio_bdev_async(struct folio *folio,
 	bio->bi_iter.bi_sector = swap_folio_sector(folio);
 	bio->bi_end_io = end_swap_bio_read;
 	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
+	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
 	count_vm_event(PSWPIN);
 	submit_bio(bio);
 }
-- 
2.43.5