[PATCH v4 19/48] rcu: dynamically allocate the rcu-kfree shrinker

[Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>]

Use new APIs to dynamically allocate the rcu-kfree shrinker.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
 kernel/rcu/tree.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7c79480bfaa0..3b20fc46c514 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3449,13 +3449,6 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 	return freed == 0 ? SHRINK_STOP : freed;
 }
 
-static struct shrinker kfree_rcu_shrinker = {
-	.count_objects = kfree_rcu_shrink_count,
-	.scan_objects = kfree_rcu_shrink_scan,
-	.batch = 0,
-	.seeks = DEFAULT_SEEKS,
-};
-
 void __init kfree_rcu_scheduler_running(void)
 {
 	int cpu;
@@ -4931,6 +4924,7 @@ static void __init kfree_rcu_batch_init(void)
 {
 	int cpu;
 	int i, j;
+	struct shrinker *kfree_rcu_shrinker;
 
 	/* Clamp it to [0:100] seconds interval. */
 	if (rcu_delay_page_cache_fill_msec < 0 ||
@@ -4962,8 +4956,18 @@ static void __init kfree_rcu_batch_init(void)
 		INIT_DELAYED_WORK(&krcp->page_cache_work, fill_page_cache_func);
 		krcp->initialized = true;
 	}
-	if (register_shrinker(&kfree_rcu_shrinker, "rcu-kfree"))
-		pr_err("Failed to register kfree_rcu() shrinker!\n");
+
+	kfree_rcu_shrinker = shrinker_alloc(0, "rcu-kfree");
+	if (!kfree_rcu_shrinker) {
+		pr_err("Failed to allocate kfree_rcu() shrinker!\n");
+		return;
+	}
+
+	kfree_rcu_shrinker->count_objects = kfree_rcu_shrink_count;
+	kfree_rcu_shrinker->scan_objects = kfree_rcu_shrink_scan;
+	kfree_rcu_shrinker->seeks = DEFAULT_SEEKS;
+
+	shrinker_register(kfree_rcu_shrinker);
 }
 
 void __init rcu_init(void)
-- 
2.30.2