[PATCH v2 8/8] rcu/kfree: Fix kfree_rcu_shrink_count() return value

From: Joel Fernandes (Google)
Date: Wed Jun 22 2022 - 18:52:27 EST


As per the comments in include/linux/shrinker.h, .count_objects callback
should return the number of freeable items, but if there are no objects
to free, SHRINK_EMPTY should be returned. The only time 0 is returned
should be when we are unable to determine the number of objects, or the
cache should be skipped for another reason.

Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 711679d10cbb..935788e8d2d7 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3722,7 +3722,7 @@ kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
atomic_set(&krcp->backoff_page_cache_fill, 1);
}

- return count;
+ return count == 0 ? SHRINK_EMPTY : count;
}

static unsigned long
--
2.37.0.rc0.104.g0611611a94-goog