From 3f98c9a62c338bbe06a215c9491e6166ea39bf82 Mon Sep 17 00:00:00 2001
From: "andrew.yang" <andrew.yang@mediatek.com>
Date: Wed, 22 Feb 2023 14:42:20 +0800
Subject: [PATCH] mm/damon/paddr: fix missing folio_put()
damon_get_folio() would always increase folio _refcount and
folio_isolate_lru() would increase folio _refcount if the folio's lru flag
is set.
If an unevictable folio isolated successfully, there will be two more
_refcount. The one from folio_isolate_lru() will be decreased in
folio_puback_lru(), but the other one from damon_get_folio() will be left
behind. This causes a pin page.
Whatever the case, the _refcount from damon_get_folio() should be
decreased.
Link: https://lkml.kernel.org/r/20230222064223.6735-1-andrew.yang@mediatek.com
Fixes: 57223ac29584 ("mm/damon/paddr: support the pageout scheme")
Signed-off-by: andrew.yang <andrew.yang@mediatek.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.16.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/damon/paddr.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 607bb69e526cf..6c655d9b56391 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -250,12 +250,11 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
folio_put(folio);
continue;
}
- if (folio_test_unevictable(folio)) {
+ if (folio_test_unevictable(folio))
folio_putback_lru(folio);
- } else {
+ else
list_add(&folio->lru, &folio_list);
- folio_put(folio);
- }
+ folio_put(folio);
}
applied = reclaim_pages(&folio_list);
cond_resched();
--
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