+ mm-damon-paddr-fix-missing-folio_put.patch added to mm-unstable branch

+ mm-damon-paddr-fix-missing-folio_put.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/paddr: fix missing folio_put()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-paddr-fix-missing-folio_put.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-paddr-fix-missing-folio_put.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "andrew.yang" <andrew.yang@mediatek.com>
Subject: mm/damon/paddr: fix missing folio_put()
Date: Wed, 22 Feb 2023 14:42:20 +0800

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(-)

--- a/mm/damon/paddr.c~mm-damon-paddr-fix-missing-folio_put
+++ a/mm/damon/paddr.c
@@ -250,12 +250,11 @@ static unsigned long damon_pa_pageout(st
 			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();
_

Patches currently in -mm which might be from andrew.yang@mediatek.com are

mm-damon-paddr-fix-missing-folio_put.patch