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
......@@ -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:
......
......@@ -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;
......
......@@ -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)
......
......@@ -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;
}
......
......@@ -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:
......
......@@ -96,15 +96,15 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb,
}
/*
* NOTE: Called under queue->lock with locally disabled BH.
* NOTE: Called under qdisc_lock(q) with locally disabled BH.
*
* __QDISC_STATE_RUNNING guarantees only one CPU can process
* this qdisc at a time. queue->lock serializes queue accesses for
* this queue AND txq->qdisc pointer itself.
* this qdisc at a time. qdisc_lock(q) serializes queue accesses for
* this queue.
*
* netif_tx_lock serializes accesses to device driver.
*
* queue->lock and netif_tx_lock are mutually exclusive,
* qdisc_lock(q) and netif_tx_lock are mutually exclusive,
* if one is grabbed, another must be free.
*
* Note, that this procedure can be called by a watchdog timer
......@@ -317,7 +317,6 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = {
};
static struct netdev_queue noop_netdev_queue = {
.lock = __SPIN_LOCK_UNLOCKED(noop_netdev_queue.lock),
.qdisc = &noop_qdisc,
};
......@@ -327,6 +326,7 @@ struct Qdisc noop_qdisc = {
.flags = TCQ_F_BUILTIN,
.ops = &noop_qdisc_ops,
.list = LIST_HEAD_INIT(noop_qdisc.list),
.q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
.dev_queue = &noop_netdev_queue,
};
EXPORT_SYMBOL(noop_qdisc);
......@@ -498,7 +498,7 @@ errout:
}
EXPORT_SYMBOL(qdisc_create_dflt);
/* Under queue->lock and BH! */
/* Under qdisc_root_lock(qdisc) and BH! */
void qdisc_reset(struct Qdisc *qdisc)
{
......@@ -526,10 +526,12 @@ static void __qdisc_destroy(struct rcu_head *head)
module_put(ops->owner);
dev_put(qdisc_dev(qdisc));
kfree_skb(qdisc->gso_skb);
kfree((char *) qdisc - qdisc->padded);
}
/* Under queue->lock and BH! */
/* Under qdisc_root_lock(qdisc) and BH! */
void qdisc_destroy(struct Qdisc *qdisc)
{
......@@ -586,13 +588,12 @@ static void transition_one_qdisc(struct net_device *dev,
struct netdev_queue *dev_queue,
void *_need_watchdog)
{
struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
int *need_watchdog_p = _need_watchdog;
spin_lock_bh(&dev_queue->lock);
rcu_assign_pointer(dev_queue->qdisc, dev_queue->qdisc_sleeping);
if (dev_queue->qdisc != &noqueue_qdisc)
rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
if (new_qdisc != &noqueue_qdisc)
*need_watchdog_p = 1;
spin_unlock_bh(&dev_queue->lock);
}
void dev_activate(struct net_device *dev)
......@@ -629,19 +630,16 @@ static void dev_deactivate_queue(struct net_device *dev,
struct sk_buff *skb = NULL;
struct Qdisc *qdisc;
spin_lock_bh(&dev_queue->lock);
qdisc = dev_queue->qdisc;
if (qdisc) {
spin_lock_bh(qdisc_lock(qdisc));
dev_queue->qdisc = qdisc_default;
qdisc_reset(qdisc);
skb = qdisc->gso_skb;
qdisc->gso_skb = NULL;
spin_unlock_bh(qdisc_lock(qdisc));
}
spin_unlock_bh(&dev_queue->lock);
kfree_skb(skb);
}
......
......@@ -156,12 +156,15 @@ teql_destroy(struct Qdisc* sch)
master->slaves = NEXT_SLAVE(q);
if (q == master->slaves) {
struct netdev_queue *txq;
spinlock_t *root_lock;
txq = netdev_get_tx_queue(master->dev, 0);
master->slaves = NULL;
spin_lock_bh(&txq->lock);
root_lock = qdisc_root_lock(txq->qdisc);
spin_lock_bh(root_lock);
qdisc_reset(txq->qdisc);
spin_unlock_bh(&txq->lock);
spin_unlock_bh(root_lock);
}
}
skb_queue_purge(&dat->q);
......
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