Use new APIs to dynamically allocate the xen-backend shrinker.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
---
 drivers/xen/xenbus/xenbus_probe_backend.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index da96c260e26b..929c41a5ccee 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -284,13 +284,9 @@ static unsigned long backend_shrink_memory_count(struct shrinker *shrinker,
 	return 0;
 }
 
-static struct shrinker backend_memory_shrinker = {
-	.count_objects = backend_shrink_memory_count,
-	.seeks = DEFAULT_SEEKS,
-};
-
 static int __init xenbus_probe_backend_init(void)
 {
+	struct shrinker *backend_memory_shrinker;
 	static struct notifier_block xenstore_notifier = {
 		.notifier_call = backend_probe_and_watch
 	};
@@ -305,8 +301,16 @@ static int __init xenbus_probe_backend_init(void)
 
 	register_xenstore_notifier(&xenstore_notifier);
 
-	if (register_shrinker(&backend_memory_shrinker, "xen-backend"))
-		pr_warn("shrinker registration failed\n");
+	backend_memory_shrinker = shrinker_alloc(0, "xen-backend");
+	if (!backend_memory_shrinker) {
+		pr_warn("shrinker allocation failed\n");
+		return 0;
+	}
+
+	backend_memory_shrinker->count_objects = backend_shrink_memory_count;
+	backend_memory_shrinker->seeks = DEFAULT_SEEKS;
+
+	shrinker_register(backend_memory_shrinker);
 
 	return 0;
 }
-- 
2.30.2