Hi Andrew,
Thank you for revising this patch!
From: "andrew.yang" andrew.yang@mediatek.com
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.
Signed-off-by: andrew.yang andrew.yang@mediatek.com Fixes: 57223ac29584 ("mm/damon/paddr: support the pageout scheme") Cc: stable@vger.kernel.org # 5.16.x
Reviewed-by: SeongJae Park sj@kernel.org
This may not cleanly applicable on 6.1.y and 6.2.y. I would post backports once this is merged in the mainline, unless others do earlier than me.
Thanks, SJ
v3: add fixes tag and cc stable v2: according to David's suggestion 1. revise subject according to SeongJae's suggestions 1. rebase to mm-unstable tree 2. remove braces for th single statements
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 607bb69e526c..6c655d9b5639 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);-- 2.18.0