netdev - [RFC PATCH bpf-next v2 09/12] bpf: Remove unused percpu counter from bpf_local_storage_map

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Message-ID: <20251002225356.1505480-10-ameryhung@gmail.com>
Date: Thu,  2 Oct 2025 15:53:48 -0700
From: Amery Hung <ameryhung@...il.com>
To: bpf@...r.kernel.org
Cc: netdev@...r.kernel.org,
	alexei.starovoitov@...il.com,
	andrii@...nel.org,
	daniel@...earbox.net,
	memxor@...il.com,
	martin.lau@...nel.org,
	kpsingh@...nel.org,
	yonghong.song@...ux.dev,
	song@...nel.org,
	haoluo@...gle.com,
	ameryhung@...il.com,
	kernel-team@...a.com
Subject: [RFC PATCH bpf-next v2 09/12] bpf: Remove unused percpu counter from bpf_local_storage_map_free

Percpu locks have been removed from cgroup and task local storage. Now
that all local storage no longer use percpu variables as locks preventing
recursion, there is no need to pass them to bpf_local_storage_map_free().
Remove the argument from the function.

Signed-off-by: Amery Hung <ameryhung@...il.com>
---
 include/linux/bpf_local_storage.h | 3 +--
 kernel/bpf/bpf_cgrp_storage.c     | 2 +-
 kernel/bpf/bpf_inode_storage.c    | 2 +-
 kernel/bpf/bpf_local_storage.c    | 7 +------
 kernel/bpf/bpf_task_storage.c     | 2 +-
 net/core/bpf_sk_storage.c         | 2 +-
 6 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
index 2a0aae5168fa..5888e012dfe3 100644
--- a/include/linux/bpf_local_storage.h
+++ b/include/linux/bpf_local_storage.h
@@ -170,8 +170,7 @@ bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
 void bpf_local_storage_destroy(struct bpf_local_storage *local_storage);
 
 void bpf_local_storage_map_free(struct bpf_map *map,
-				struct bpf_local_storage_cache *cache,
-				int __percpu *busy_counter);
+				struct bpf_local_storage_cache *cache);
 
 int bpf_local_storage_map_check_btf(const struct bpf_map *map,
 				    const struct btf *btf,
diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c
index 4f9cfa032870..a57abb2956d5 100644
--- a/kernel/bpf/bpf_cgrp_storage.c
+++ b/kernel/bpf/bpf_cgrp_storage.c
@@ -119,7 +119,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 
 static void cgroup_storage_map_free(struct bpf_map *map)
 {
-	bpf_local_storage_map_free(map, &cgroup_cache, NULL);
+	bpf_local_storage_map_free(map, &cgroup_cache);
 }
 
 /* *gfp_flags* is a hidden argument provided by the verifier */
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index cedc99184dad..470f4b02c79e 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -184,7 +184,7 @@ static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
 
 static void inode_storage_map_free(struct bpf_map *map)
 {
-	bpf_local_storage_map_free(map, &inode_cache, NULL);
+	bpf_local_storage_map_free(map, &inode_cache);
 }
 
 const struct bpf_map_ops inode_storage_map_ops = {
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 572956e2a72d..3ce4dd7e7fc6 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -917,8 +917,7 @@ bpf_local_storage_map_alloc(union bpf_attr *attr,
 }
 
 void bpf_local_storage_map_free(struct bpf_map *map,
-				struct bpf_local_storage_cache *cache,
-				int __percpu *busy_counter)
+				struct bpf_local_storage_cache *cache)
 {
 	struct bpf_local_storage_map_bucket *b;
 	struct bpf_local_storage_elem *selem;
@@ -951,11 +950,7 @@ void bpf_local_storage_map_free(struct bpf_map *map,
 		while ((selem = hlist_entry_safe(
 				rcu_dereference_raw(hlist_first_rcu(&b->list)),
 				struct bpf_local_storage_elem, map_node))) {
-			if (busy_counter)
-				this_cpu_inc(*busy_counter);
 			while (bpf_selem_unlink(selem, true));
-			if (busy_counter)
-				this_cpu_dec(*busy_counter);
 			cond_resched_rcu();
 		}
 		rcu_read_unlock();
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index dd858226ada2..4d53aebe6784 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -217,7 +217,7 @@ static struct bpf_map *task_storage_map_alloc(union bpf_attr *attr)
 
 static void task_storage_map_free(struct bpf_map *map)
 {
-	bpf_local_storage_map_free(map, &task_cache, NULL);
+	bpf_local_storage_map_free(map, &task_cache);
 }
 
 BTF_ID_LIST_GLOBAL_SINGLE(bpf_local_storage_map_btf_id, struct, bpf_local_storage_map)
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 7b3d44667cee..7037b841cf11 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -62,7 +62,7 @@ void bpf_sk_storage_free(struct sock *sk)
 
 static void bpf_sk_storage_map_free(struct bpf_map *map)
 {
-	bpf_local_storage_map_free(map, &sk_cache, NULL);
+	bpf_local_storage_map_free(map, &sk_cache);
 }
 
 static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
-- 
2.47.3