diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index eb342994675a..4908109d924f 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -4,6 +4,8 @@
 
 #include <linux/atomic.h>
 #include <linux/types.h>
+#include <linux/refcount.h>
+#include <linux/completion.h>
 
 #define SHRINKER_UNIT_BITS	BITS_PER_LONG
 
@@ -87,6 +89,17 @@ struct shrinker {
 	int seeks;	/* seeks to recreate an obj */
 	unsigned flags;
 
+	/*
+	 * The reference count of this shrinker. Registered shrinker have an
+	 * initial refcount of 1, then the lookup operations are now allowed
+	 * to use it via shrinker_try_get(). Later in the unregistration step,
+	 * the initial refcount will be discarded, and will free the shrinker
+	 * asynchronously via RCU after its refcount reaches 0.
+	 */
+	refcount_t refcount;
+	struct completion done;	/* use to wait for refcount to reach 0 */
+	struct rcu_head rcu;
+
 	void *private_data;
 
 	/* These are for internal use */
@@ -120,6 +133,17 @@ struct shrinker *shrinker_alloc(unsigned int flags, const char *fmt, ...);
 void shrinker_register(struct shrinker *shrinker);
 void shrinker_free(struct shrinker *shrinker);
 
+static inline bool shrinker_try_get(struct shrinker *shrinker)
+{
+	return refcount_inc_not_zero(&shrinker->refcount);
+}
+
+static inline void shrinker_put(struct shrinker *shrinker)
+{
+	if (refcount_dec_and_test(&shrinker->refcount))
+		complete(&shrinker->done);
+}
+
 #ifdef CONFIG_SHRINKER_DEBUG
 extern int __printf(2, 3) shrinker_debugfs_rename(struct shrinker *shrinker,
 						  const char *fmt, ...);
diff --git a/mm/shrinker.c b/mm/shrinker.c
index 578599c9e12e..2b8c1f1bbf2d 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -2,6 +2,7 @@
 #include <linux/memcontrol.h>
 #include <linux/rwsem.h>
 #include <linux/shrinker.h>
+#include <linux/rculist.h>
 #include <trace/events/vmscan.h>
 
 #include "internal.h"
@@ -576,33 +577,50 @@ unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
 	if (!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg))
 		return shrink_slab_memcg(gfp_mask, nid, memcg, priority);
 
-	if (!down_read_trylock(&shrinker_rwsem))
-		goto out;
-
-	list_for_each_entry(shrinker, &shrinker_list, list) {
+	/*
+	 * lockless algorithm of global shrink.
+	 *
+	 * In the unregistration setp, the shrinker will be freed asynchronously
+	 * via RCU after its refcount reaches 0. So both rcu_read_lock() and
+	 * shrinker_try_get() can be used to ensure the existence of the shrinker.
+	 *
+	 * So in the global shrink:
+	 *  step 1: use rcu_read_lock() to guarantee existence of the shrinker
+	 *          and the validity of the shrinker_list walk.
+	 *  step 2: use shrinker_try_get() to try get the refcount, if successful,
+	 *          then the existence of the shrinker can also be guaranteed,
+	 *          so we can release the RCU lock to do do_shrink_slab() that
+	 *          may sleep.
+	 *  step 3: *MUST* to reacquire the RCU lock before calling shrinker_put(),
+	 *          which ensures that neither this shrinker nor the next shrinker
+	 *          will be freed in the next traversal operation.
+	 *  step 4: do shrinker_put() paired with step 2 to put the refcount,
+	 *          if the refcount reaches 0, then wake up the waiter in
+	 *          shrinker_free() by calling complete().
+	 */
+	rcu_read_lock();
+	list_for_each_entry_rcu(shrinker, &shrinker_list, list) {
 		struct shrink_control sc = {
 			.gfp_mask = gfp_mask,
 			.nid = nid,
 			.memcg = memcg,
 		};
 
+		if (!shrinker_try_get(shrinker))
+			continue;
+
+		rcu_read_unlock();
+
 		ret = do_shrink_slab(&sc, shrinker, priority);
 		if (ret == SHRINK_EMPTY)
 			ret = 0;
 		freed += ret;
-		/*
-		 * Bail out if someone want to register a new shrinker to
-		 * prevent the registration from being stalled for long periods
-		 * by parallel ongoing shrinking.
-		 */
-		if (rwsem_is_contended(&shrinker_rwsem)) {
-			freed = freed ? : 1;
-			break;
-		}
+
+		rcu_read_lock();
+		shrinker_put(shrinker);
 	}
 
-	up_read(&shrinker_rwsem);
-out:
+	rcu_read_unlock();
 	cond_resched();
 	return freed;
 }
@@ -670,13 +688,29 @@ void shrinker_register(struct shrinker *shrinker)
 	}
 
 	down_write(&shrinker_rwsem);
-	list_add_tail(&shrinker->list, &shrinker_list);
+	list_add_tail_rcu(&shrinker->list, &shrinker_list);
 	shrinker->flags |= SHRINKER_REGISTERED;
 	shrinker_debugfs_add(shrinker);
 	up_write(&shrinker_rwsem);
+
+	init_completion(&shrinker->done);
+	/*
+	 * Now the shrinker is fully set up, take the first reference to it to
+	 * indicate that lookup operations are now allowed to use it via
+	 * shrinker_try_get().
+	 */
+	refcount_set(&shrinker->refcount, 1);
 }
 EXPORT_SYMBOL_GPL(shrinker_register);
 
+static void shrinker_free_rcu_cb(struct rcu_head *head)
+{
+	struct shrinker *shrinker = container_of(head, struct shrinker, rcu);
+
+	kfree(shrinker->nr_deferred);
+	kfree(shrinker);
+}
+
 void shrinker_free(struct shrinker *shrinker)
 {
 	struct dentry *debugfs_entry = NULL;
@@ -685,9 +719,25 @@ void shrinker_free(struct shrinker *shrinker)
 	if (!shrinker)
 		return;
 
+	if (shrinker->flags & SHRINKER_REGISTERED) {
+		/* drop the initial refcount */
+		shrinker_put(shrinker);
+		/*
+		 * Wait for all lookups of the shrinker to complete, after that,
+		 * no shrinker is running or will run again, then we can safely
+		 * free it asynchronously via RCU and safely free the structure
+		 * where the shrinker is located, such as super_block etc.
+		 */
+		wait_for_completion(&shrinker->done);
+	}
+
 	down_write(&shrinker_rwsem);
 	if (shrinker->flags & SHRINKER_REGISTERED) {
-		list_del(&shrinker->list);
+		/*
+		 * Now we can safely remove it from the shrinker_list and then
+		 * free it.
+		 */
+		list_del_rcu(&shrinker->list);
 		debugfs_entry = shrinker_debugfs_detach(shrinker, &debugfs_id);
 		shrinker->flags &= ~SHRINKER_REGISTERED;
 	} else {
@@ -701,9 +751,6 @@ void shrinker_free(struct shrinker *shrinker)
 	if (debugfs_entry)
 		shrinker_debugfs_remove(debugfs_entry, debugfs_id);
 
-	kfree(shrinker->nr_deferred);
-	shrinker->nr_deferred = NULL;
-
-	kfree(shrinker);
+	call_rcu(&shrinker->rcu, shrinker_free_rcu_cb);
 }
 EXPORT_SYMBOL_GPL(shrinker_free);
