[PATCH] mm/damon/paddr: fix pin page problem

[Andrew Yang]

From: "andrew.yang" <andrew.yang at mediatek.com>

damon_get_page() would always increase page _refcount and
isolate_lru_page() would increase page _refcount if the page's lru
flag is set.

If a unevictable page isolated successfully, there will be two more
_refcount. The one from isolate_lru_page() will be decreased in
putback_lru_page(), but the other one from damon_get_page() will be
left behind. This causes a pin page.

Whatever the case, the _refcount from damon_get_page() should be
decreased.

Signed-off-by: andrew.yang <andrew.yang at mediatek.com>
---
 mm/damon/paddr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index e1a4315c4be6..56d8abd08fb1 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -223,8 +223,8 @@ static unsigned long damon_pa_pageout(struct damon_region *r)
 			putback_lru_page(page);
 		} else {
 			list_add(&page->lru, &page_list);
-			put_page(page);
 		}
+		put_page(page);
 	}
 	applied = reclaim_pages(&page_list);
 	cond_resched();
-- 
2.18.0