Commit 83874000 authored by David S. Miller's avatar David S. Miller
Browse files

pkt_sched: Kill netdev_queue lock. 



We can simply use the qdisc->q.lock for all of the
qdisc tree synchronization.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c7e4f3bb

drivers/net/ifb.c

+0 −20
Original line number Diff line number Diff line
@@ -35,7 +35,6 @@ 
#include <linux/moduleparam.h>

#include <net/pkt_sched.h>

#include <net/net_namespace.h>

#include <linux/lockdep.h>



#define TX_TIMEOUT  (2*HZ)
@@ -228,22 +227,6 @@ static struct rtnl_link_ops ifb_link_ops __read_mostly = { 
module_param(numifbs, int, 0);

MODULE_PARM_DESC(numifbs, "Number of ifb devices");



/*

 * dev_ifb's TX queue lock is usually taken after dev->rx_queue.lock,

 * reversely to e.g. qdisc_lock_tree(). It should be safe until

 * ifb doesn't take dev's TX queue lock with dev_ifb->rx_queue.lock.

 * But lockdep should know that ifb has different locks from dev.

 */

static struct lock_class_key ifb_tx_queue_lock_key;

static struct lock_class_key ifb_rx_queue_lock_key;



static void set_tx_lockdep_key(struct net_device *dev,

			       struct netdev_queue *txq,

			       void *_unused)

{

	lockdep_set_class(&txq->lock, &ifb_tx_queue_lock_key);

}



static int __init ifb_init_one(int index)

{

	struct net_device *dev_ifb;
@@ -264,9 +247,6 @@ static int __init ifb_init_one(int index) 
	if (err < 0)

		goto err;



	netdev_for_each_tx_queue(dev_ifb, set_tx_lockdep_key, NULL);

	lockdep_set_class(&dev_ifb->rx_queue.lock, &ifb_rx_queue_lock_key);



	return 0;



err:

include/linux/netdevice.h

+0 −1
Original line number Diff line number Diff line
@@ -443,7 +443,6 @@ enum netdev_queue_state_t 
};



struct netdev_queue {

	spinlock_t		lock;

	struct net_device	*dev;

	struct Qdisc		*qdisc;

	unsigned long		state;

include/net/sch_generic.h

+6 −1
Original line number Diff line number Diff line
@@ -163,6 +163,11 @@ struct tcf_proto 
	struct tcf_proto_ops	*ops;

};



static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)

{

	return &qdisc->q.lock;

}



static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)

{

	return qdisc->dev_queue->qdisc;
@@ -172,7 +177,7 @@ static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc) 
{

	struct Qdisc *root = qdisc_root(qdisc);



	return &root->dev_queue->lock;

	return qdisc_lock(root);

}



static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)

net/core/dev.c

+5 −4
Original line number Diff line number Diff line
@@ -2080,10 +2080,12 @@ static int ing_filter(struct sk_buff *skb) 


	rxq = &dev->rx_queue;



	spin_lock(&rxq->lock);

	if ((q = rxq->qdisc) != NULL)

	q = rxq->qdisc;

	if (q) {

		spin_lock(qdisc_lock(q));

		result = q->enqueue(skb, q);

	spin_unlock(&rxq->lock);

		spin_unlock(qdisc_lock(q));

	}



	return result;

}
@@ -4173,7 +4175,6 @@ static void netdev_init_one_queue(struct net_device *dev, 
				  struct netdev_queue *queue,

				  void *_unused)

{

	spin_lock_init(&queue->lock);

	queue->dev = dev;

}

net/mac80211/wme.c

+12 −7
Original line number Diff line number Diff line
@@ -237,12 +237,14 @@ void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local, 
		ieee80211_requeue(local, agg_queue);

	} else {

		struct netdev_queue *txq;

		spinlock_t *root_lock;



		txq = netdev_get_tx_queue(local->mdev, agg_queue);

		root_lock = qdisc_root_lock(txq->qdisc);



		spin_lock_bh(&txq->lock);

		spin_lock_bh(root_lock);

		qdisc_reset(txq->qdisc);

		spin_unlock_bh(&txq->lock);

		spin_unlock_bh(root_lock);

	}

}
@@ -250,6 +252,7 @@ void ieee80211_requeue(struct ieee80211_local *local, int queue) 
{

	struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, queue);

	struct sk_buff_head list;

	spinlock_t *root_lock;

	struct Qdisc *qdisc;

	u32 len;
@@ -261,14 +264,15 @@ void ieee80211_requeue(struct ieee80211_local *local, int queue) 


	skb_queue_head_init(&list);



	spin_lock(&txq->lock);

	root_lock = qdisc_root_lock(qdisc);

	spin_lock(root_lock);

	for (len = qdisc->q.qlen; len > 0; len--) {

		struct sk_buff *skb = qdisc->dequeue(qdisc);



		if (skb)

			__skb_queue_tail(&list, skb);

	}

	spin_unlock(&txq->lock);

	spin_unlock(root_lock);



	for (len = list.qlen; len > 0; len--) {

		struct sk_buff *skb = __skb_dequeue(&list);
@@ -280,12 +284,13 @@ void ieee80211_requeue(struct ieee80211_local *local, int queue) 


		txq = netdev_get_tx_queue(local->mdev, new_queue);



		spin_lock(&txq->lock);



		qdisc = rcu_dereference(txq->qdisc);

		qdisc->enqueue(skb, qdisc);

		root_lock = qdisc_root_lock(qdisc);



		spin_unlock(&txq->lock);

		spin_lock(root_lock);

		qdisc->enqueue(skb, qdisc);

		spin_unlock(root_lock);

	}



out_unlock: