[PATCH v6 19/45] mm: workingset: dynamically allocate the mm-shadow shrinker

[Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>]

Use new APIs to dynamically allocate the mm-shadow shrinker.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
 mm/workingset.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/mm/workingset.c b/mm/workingset.c
index da58a26d0d4d..b192e44a0e7c 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -763,13 +763,6 @@ static unsigned long scan_shadow_nodes(struct shrinker *shrinker,
 					NULL);
 }
 
-static struct shrinker workingset_shadow_shrinker = {
-	.count_objects = count_shadow_nodes,
-	.scan_objects = scan_shadow_nodes,
-	.seeks = 0, /* ->count reports only fully expendable nodes */
-	.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE,
-};
-
 /*
  * Our list_lru->lock is IRQ-safe as it nests inside the IRQ-safe
  * i_pages lock.
@@ -778,9 +771,10 @@ static struct lock_class_key shadow_nodes_key;
 
 static int __init workingset_init(void)
 {
+	struct shrinker *workingset_shadow_shrinker;
 	unsigned int timestamp_bits;
 	unsigned int max_order;
-	int ret;
+	int ret = -ENOMEM;
 
 	BUILD_BUG_ON(BITS_PER_LONG < EVICTION_SHIFT);
 	/*
@@ -797,17 +791,26 @@ static int __init workingset_init(void)
 	pr_info("workingset: timestamp_bits=%d max_order=%d bucket_order=%u\n",
 	       timestamp_bits, max_order, bucket_order);
 
-	ret = prealloc_shrinker(&workingset_shadow_shrinker, "mm-shadow");
-	if (ret)
+	workingset_shadow_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE |
+						    SHRINKER_MEMCG_AWARE,
+						    "mm-shadow");
+	if (!workingset_shadow_shrinker)
 		goto err;
+
 	ret = __list_lru_init(&shadow_nodes, true, &shadow_nodes_key,
-			      &workingset_shadow_shrinker);
+			      workingset_shadow_shrinker);
 	if (ret)
 		goto err_list_lru;
-	register_shrinker_prepared(&workingset_shadow_shrinker);
+
+	workingset_shadow_shrinker->count_objects = count_shadow_nodes;
+	workingset_shadow_shrinker->scan_objects = scan_shadow_nodes;
+	/* ->count reports only fully expendable nodes */
+	workingset_shadow_shrinker->seeks = 0;
+
+	shrinker_register(workingset_shadow_shrinker);
 	return 0;
 err_list_lru:
-	free_prealloced_shrinker(&workingset_shadow_shrinker);
+	shrinker_free(workingset_shadow_shrinker);
 err:
 	return ret;
 }
-- 
2.30.2