[tip: core/rcu] rcu: Stop shrinker loop

[tip-bot2 for Peter Enderborg]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     c6dfd72b7a3b70a2054db0f73245ea2f762a8452
Gitweb:        https://git.kernel.org/tip/c6dfd72b7a3b70a2054db0f73245ea2f762a8452
Author:        Peter Enderborg <peter.enderborg@xxxxxxxx>
AuthorDate:    Thu, 04 Jun 2020 12:23:20 +02:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 29 Jun 2020 11:58:51 -07:00

rcu: Stop shrinker loop

The count and scan can be separated in time, and there is a fair chance
that all work is already done when the scan starts, which might in turn
result in a needless retry.  This commit therefore avoids this retry by
returning SHRINK_STOP.

Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Peter Enderborg <peter.enderborg@xxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 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 d17e5a0..c8196fa 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3332,7 +3332,7 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 			break;
 	}
 
-	return freed;
+	return freed == 0 ? SHRINK_STOP : freed;
 }
 
 static struct shrinker kfree_rcu_shrinker = {