From 83874000929ed63aef30b44083a9f713135ff040 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 17 Jul 2008 00:53:03 -0700 Subject: [PATCH] pkt_sched: Kill netdev_queue lock. We can simply use the qdisc->q.lock for all of the qdisc tree synchronization. Signed-off-by: David S. Miller --- drivers/net/ifb.c | 20 -------------------- include/linux/netdevice.h | 1 - include/net/sch_generic.h | 7 ++++++- net/core/dev.c | 9 +++++---- net/mac80211/wme.c | 19 ++++++++++++------- net/sched/sch_generic.c | 32 +++++++++++++++----------------- net/sched/sch_teql.c | 7 +++++-- 7 files changed, 43 insertions(+), 52 deletions(-) diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index 897b05e79ed0..0960e69b2da4 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -35,7 +35,6 @@ #include #include #include -#include #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: diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3170bcef734b..9c5a68850114 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -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; diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 1eef8d0c9990..2902a42564f0 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -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) diff --git a/net/core/dev.c b/net/core/dev.c index 6741e344ac59..32a13772c1cb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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; } diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c index b21cfec4b6ce..6e8099e77043 100644 --- a/net/mac80211/wme.c +++ b/net/mac80211/wme.c @@ -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: diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 3d53e92ad9c8..8fc580b3e173 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -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); } diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c index ade3372221c7..8b0ff345f9da 100644 --- a/net/sched/sch_teql.c +++ b/net/sched/sch_teql.c @@ -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);