Commit 8192edef authored by Gustavo Padovan's avatar Gustavo Padovan
Browse files

Bluetooth: Use RCU to manipulate chan_list 



Instead of using tasklet_disable() to prevent acess to the channel use, we
can use RCU and improve the performance of our code.

Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarGustavo F. Padovan <padovan@profusion.mobi>
parent d01b2ff4

net/bluetooth/hci_conn.c

+6 −8
Original line number Diff line number Diff line
@@ -960,9 +960,7 @@ struct hci_chan *hci_chan_create(struct hci_conn *conn) 
	chan->conn = conn;

	skb_queue_head_init(&chan->data_q);



	tasklet_disable(&hdev->tx_task);

	list_add(&conn->chan_list, &chan->list);

	tasklet_enable(&hdev->tx_task);

	list_add_rcu(&chan->list, &conn->chan_list);



	return chan;

}
@@ -974,9 +972,9 @@ int hci_chan_del(struct hci_chan *chan) 


	BT_DBG("%s conn %p chan %p", hdev->name, conn, chan);



	tasklet_disable(&hdev->tx_task);

	list_del(&chan->list);

	tasklet_enable(&hdev->tx_task);

	list_del_rcu(&chan->list);



	synchronize_rcu();



	skb_queue_purge(&chan->data_q);

	kfree(chan);
@@ -986,10 +984,10 @@ int hci_chan_del(struct hci_chan *chan) 


void hci_chan_list_flush(struct hci_conn *conn)

{

	struct hci_chan *chan, *tmp;

	struct hci_chan *chan;



	BT_DBG("conn %p", conn);



	list_for_each_entry_safe(chan, tmp, &conn->chan_list, list)

	list_for_each_entry_rcu(chan, &conn->chan_list, list)

		hci_chan_del(chan);

}

net/bluetooth/hci_core.c

+10 −2
Original line number Diff line number Diff line
@@ -2135,7 +2135,9 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type, 


		conn_num++;



		list_for_each_entry(tmp, &conn->chan_list, list) {

		rcu_read_lock();



		list_for_each_entry_rcu(tmp, &conn->chan_list, list) {

			struct sk_buff *skb;



			if (skb_queue_empty(&tmp->data_q))
@@ -2159,6 +2161,8 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type, 
			}

		}



		rcu_read_unlock();



		if (hci_conn_num(hdev, type) == conn_num)

			break;

	}
@@ -2207,7 +2211,9 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) 


		num++;



		list_for_each_entry(chan, &conn->chan_list, list) {

		rcu_read_lock();



		list_for_each_entry_rcu(chan, &conn->chan_list, list) {

			struct sk_buff *skb;



			if (chan->sent) {
@@ -2228,6 +2234,8 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) 
								skb->priority);

		}



		rcu_read_unlock();



		if (hci_conn_num(hdev, type) == num)

			break;

	}