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 <davem@davemloft.net>
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 3d53e92..8fc580b 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -96,15 +96,15 @@
}
/*
- * 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 @@
};
static struct netdev_queue noop_netdev_queue = {
- .lock = __SPIN_LOCK_UNLOCKED(noop_netdev_queue.lock),
.qdisc = &noop_qdisc,
};
@@ -327,6 +326,7 @@
.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 @@
}
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 @@
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 @@
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 @@
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);
}