Commit bf4c6325 authored by Gustavo Padovan's avatar Gustavo Padovan
Browse files

Bluetooth: convert conn hash to RCU 



Handling hci_conn_hash with RCU make us avoid some locking and disable
tasklets.

Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarGustavo F. Padovan <padovan@profusion.mobi>
parent 8192edef

include/net/bluetooth/hci_core.h

+31 −14
Original line number Diff line number Diff line
@@ -392,7 +392,7 @@ static inline void hci_conn_hash_init(struct hci_dev *hdev) 
static inline void hci_conn_hash_add(struct hci_dev *hdev, struct hci_conn *c)

{

	struct hci_conn_hash *h = &hdev->conn_hash;

	list_add(&c->list, &h->list);

	list_add_rcu(&c->list, &h->list);

	switch (c->type) {

	case ACL_LINK:

		h->acl_num++;
@@ -410,7 +410,10 @@ static inline void hci_conn_hash_add(struct hci_dev *hdev, struct hci_conn *c) 
static inline void hci_conn_hash_del(struct hci_dev *hdev, struct hci_conn *c)

{

	struct hci_conn_hash *h = &hdev->conn_hash;

	list_del(&c->list);



	list_del_rcu(&c->list);

	synchronize_rcu();



	switch (c->type) {

	case ACL_LINK:

		h->acl_num--;
@@ -445,14 +448,18 @@ static inline struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev, 
								__u16 handle)

{

	struct hci_conn_hash *h = &hdev->conn_hash;

	struct list_head *p;

	struct hci_conn  *c;



	list_for_each(p, &h->list) {

		c = list_entry(p, struct hci_conn, list);

		if (c->handle == handle)

	rcu_read_lock();



	list_for_each_entry_rcu(c, &h->list, list) {

		if (c->handle == handle) {

			rcu_read_unlock();

			return c;

		}

	}

	rcu_read_unlock();



	return NULL;

}
@@ -460,14 +467,19 @@ static inline struct hci_conn *hci_conn_hash_lookup_ba(struct hci_dev *hdev, 
							__u8 type, bdaddr_t *ba)

{

	struct hci_conn_hash *h = &hdev->conn_hash;

	struct list_head *p;

	struct hci_conn  *c;



	list_for_each(p, &h->list) {

		c = list_entry(p, struct hci_conn, list);

		if (c->type == type && !bacmp(&c->dst, ba))

	rcu_read_lock();



	list_for_each_entry_rcu(c, &h->list, list) {

		if (c->type == type && !bacmp(&c->dst, ba)) {

			rcu_read_unlock();

			return c;

		}

	}



	rcu_read_unlock();



	return NULL;

}
@@ -475,14 +487,19 @@ static inline struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev, 
							__u8 type, __u16 state)

{

	struct hci_conn_hash *h = &hdev->conn_hash;

	struct list_head *p;

	struct hci_conn  *c;



	list_for_each(p, &h->list) {

		c = list_entry(p, struct hci_conn, list);

		if (c->type == type && c->state == state)

	rcu_read_lock();



	list_for_each_entry_rcu(c, &h->list, list) {

		if (c->type == type && c->state == state) {

			rcu_read_unlock();

			return c;

		}

	}



	rcu_read_unlock();



	return NULL;

}

net/bluetooth/hci_conn.c

+9 −10
Original line number Diff line number Diff line
@@ -418,18 +418,17 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst) 


	hci_dev_hold(hdev);



	tasklet_disable(&hdev->tx_task);



	hci_conn_hash_add(hdev, conn);

	if (hdev->notify)

	if (hdev->notify) {

		tasklet_disable(&hdev->tx_task);

		hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);

		tasklet_enable(&hdev->tx_task);

	}



	atomic_set(&conn->devref, 0);



	hci_conn_init_sysfs(conn);



	tasklet_enable(&hdev->tx_task);



	return conn;

}
@@ -465,15 +464,15 @@ int hci_conn_del(struct hci_conn *conn) 
		}

	}



	tasklet_disable(&hdev->tx_task);



	hci_chan_list_flush(conn);



	hci_conn_hash_del(hdev, conn);

	if (hdev->notify)

	if (hdev->notify) {

		tasklet_disable(&hdev->tx_task);

		hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);



		tasklet_enable(&hdev->tx_task);

	}



	skb_queue_purge(&conn->data_q);
@@ -808,7 +807,7 @@ void hci_conn_hash_flush(struct hci_dev *hdev) 


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



	list_for_each_entry(c, &h->list, list) {

	list_for_each_entry_rcu(c, &h->list, list) {

		c->state = BT_CLOSED;



		hci_proto_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);

net/bluetooth/hci_core.c

+22 −12
Original line number Diff line number Diff line
@@ -2050,7 +2050,10 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int 


	/* We don't have to lock device here. Connections are always

	 * added and removed with TX task disabled. */

	list_for_each_entry(c, &h->list, list) {



	rcu_read_lock();



	list_for_each_entry_rcu(c, &h->list, list) {

		if (c->type != type || skb_queue_empty(&c->data_q))

			continue;
@@ -2068,6 +2071,8 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int 
			break;

	}



	rcu_read_unlock();



	if (conn) {

		int cnt, q;
@@ -2103,14 +2108,18 @@ static inline void hci_link_tx_to(struct hci_dev *hdev, __u8 type) 


	BT_ERR("%s link tx timeout", hdev->name);



	rcu_read_lock();



	/* Kill stalled connections */

	list_for_each_entry(c, &h->list, list) {

	list_for_each_entry_rcu(c, &h->list, list) {

		if (c->type == type && c->sent) {

			BT_ERR("%s killing stalled connection %s",

				hdev->name, batostr(&c->dst));

			hci_acl_disconn(c, 0x13);

		}

	}



	rcu_read_unlock();

}



static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type,
@@ -2124,7 +2133,9 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type, 


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



	list_for_each_entry(conn, &h->list, list) {

	rcu_read_lock();



	list_for_each_entry_rcu(conn, &h->list, list) {

		struct hci_chan *tmp;



		if (conn->type != type)
@@ -2135,8 +2146,6 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type, 


		conn_num++;



		rcu_read_lock();



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

			struct sk_buff *skb;
@@ -2161,12 +2170,12 @@ 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;

	}



	rcu_read_unlock();



	if (!chan)

		return NULL;
@@ -2200,7 +2209,9 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) 


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



	list_for_each_entry(conn, &h->list, list) {

	rcu_read_lock();



	list_for_each_entry_rcu(conn, &h->list, list) {

		struct hci_chan *chan;



		if (conn->type != type)
@@ -2211,8 +2222,6 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) 


		num++;



		rcu_read_lock();



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

			struct sk_buff *skb;
@@ -2234,11 +2243,12 @@ static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) 
								skb->priority);

		}



		rcu_read_unlock();



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

			break;

	}



	rcu_read_unlock();



}



static inline void hci_sched_acl(struct hci_dev *hdev)