deferred_split_scan() gets called from reclaim path. Waiting for page
lock may lead to deadlock there.
Replace lock_page() with trylock_page() and skip the page if we failed
to lock it. We will get to the page on the next scan.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 87ab9b8f56b5..529cf36b7edb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2783,11 +2783,13 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
list_for_each_safe(pos, next, &list) {
page = list_entry((void *)pos, struct page, mapping);
- lock_page(page);
+ if (!trylock_page(page))
+ goto next;
/* split_huge_page() removes page from list on success */
if (!split_huge_page(page))
split++;
unlock_page(page);
+next:
put_page(page);
}
--
2.16.1
