From: Johan Hedberg <johan.hedberg@xxxxxxxxx>
The HCI callback list (hci_cb_list) is most of the time used in a
read-only fashion. Converting it to use RCU instead of rwlock makes the
access to it more efficient.
Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 25 ++++++++++++-------------
net/bluetooth/hci_core.c | 10 +++-------
2 files changed, 15 insertions(+), 20 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a26421ec7d99..3a35e9d219c3 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -463,7 +463,6 @@ struct hci_conn_params {
extern struct list_head hci_dev_list;
extern struct list_head hci_cb_list;
-extern rwlock_t hci_cb_list_lock;
/* ----- HCI interface to upper protocols ----- */
int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr);
@@ -1085,12 +1084,12 @@ static inline void hci_auth_cfm(struct hci_conn *conn, __u8 status)
encrypt = test_bit(HCI_CONN_ENCRYPT, &conn->flags) ? 0x01 : 0x00;
- read_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(cb, &hci_cb_list, list) {
if (cb->security_cfm)
cb->security_cfm(conn, status, encrypt);
}
- read_unlock(&hci_cb_list_lock);
+ rcu_read_unlock();
}
static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status,
@@ -1106,24 +1105,24 @@ static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status,
hci_proto_encrypt_cfm(conn, status, encrypt);
- read_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(cb, &hci_cb_list, list) {
if (cb->security_cfm)
cb->security_cfm(conn, status, encrypt);
}
- read_unlock(&hci_cb_list_lock);
+ rcu_read_unlock();
}
static inline void hci_key_change_cfm(struct hci_conn *conn, __u8 status)
{
struct hci_cb *cb;
- read_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(cb, &hci_cb_list, list) {
if (cb->key_change_cfm)
cb->key_change_cfm(conn, status);
}
- read_unlock(&hci_cb_list_lock);
+ rcu_read_unlock();
}
static inline void hci_role_switch_cfm(struct hci_conn *conn, __u8 status,
@@ -1131,12 +1130,12 @@ static inline void hci_role_switch_cfm(struct hci_conn *conn, __u8 status,
{
struct hci_cb *cb;
- read_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(cb, &hci_cb_list, list) {
if (cb->role_switch_cfm)
cb->role_switch_cfm(conn, status, role);
}
- read_unlock(&hci_cb_list_lock);
+ rcu_read_unlock();
}
static inline bool eir_has_data_type(u8 *data, size_t data_len, u8 type)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index ae96cf9bef6d..a1f5ebc9197e 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -48,7 +48,6 @@ LIST_HEAD(hci_dev_list);
/* HCI callback list */
LIST_HEAD(hci_cb_list);
-DEFINE_RWLOCK(hci_cb_list_lock);
/* HCI ID Numbering */
static DEFINE_IDA(hci_index_ida);
@@ -4359,9 +4358,7 @@ int hci_register_cb(struct hci_cb *cb)
{
BT_DBG("%p name %s", cb, cb->name);
- write_lock(&hci_cb_list_lock);
- list_add(&cb->list, &hci_cb_list);
- write_unlock(&hci_cb_list_lock);
+ list_add_rcu(&cb->list, &hci_cb_list);
return 0;
}
@@ -4371,9 +4368,8 @@ int hci_unregister_cb(struct hci_cb *cb)
{
BT_DBG("%p name %s", cb, cb->name);
- write_lock(&hci_cb_list_lock);
- list_del(&cb->list);
- write_unlock(&hci_cb_list_lock);
+ list_del_rcu(&cb->list);
+ synchronize_rcu();
return 0;
}
--
1.9.3
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