diff options
Diffstat (limited to 'net/sched/sch_generic.c')
| -rw-r--r-- | net/sched/sch_generic.c | 35 |
1 files changed, 12 insertions, 23 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 52eb3439d7c6..3385ee592541 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -36,34 +36,27 @@ /* Main transmission queue. */ -/* Main qdisc structure lock. - - However, modifications - to data, participating in scheduling must be additionally - protected with dev->queue_lock spinlock. - - The idea is the following: - - enqueue, dequeue are serialized via top level device - spinlock dev->queue_lock. - - tree walking is protected by read_lock(qdisc_tree_lock) - and this lock is used only in process context. - - updates to tree are made only under rtnl semaphore, - hence this lock may be made without local bh disabling. - - qdisc_tree_lock must be grabbed BEFORE dev->queue_lock! +/* Modifications to data participating in scheduling must be protected with + * dev->queue_lock spinlock. + * + * The idea is the following: + * - enqueue, dequeue are serialized via top level device + * spinlock dev->queue_lock. + * - ingress filtering is serialized via top level device + * spinlock dev->ingress_lock. + * - updates to tree and tree walking are only done under the rtnl mutex. */ -DEFINE_RWLOCK(qdisc_tree_lock); void qdisc_lock_tree(struct net_device *dev) { - write_lock(&qdisc_tree_lock); spin_lock_bh(&dev->queue_lock); + spin_lock(&dev->ingress_lock); } void qdisc_unlock_tree(struct net_device *dev) { + spin_unlock(&dev->ingress_lock); spin_unlock_bh(&dev->queue_lock); - write_unlock(&qdisc_tree_lock); } /* @@ -442,7 +435,6 @@ struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) sch->dequeue = ops->dequeue; sch->dev = dev; dev_hold(dev); - sch->stats_lock = &dev->queue_lock; atomic_set(&sch->refcnt, 1); return sch; @@ -458,6 +450,7 @@ struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops, sch = qdisc_alloc(dev, ops); if (IS_ERR(sch)) goto errout; + sch->stats_lock = &dev->queue_lock; sch->parent = parentid; if (!ops->init || ops->init(sch, NULL) == 0) @@ -528,15 +521,11 @@ void dev_activate(struct net_device *dev) printk(KERN_INFO "%s: activation failed\n", dev->name); return; } - write_lock(&qdisc_tree_lock); list_add_tail(&qdisc->list, &dev->qdisc_list); - write_unlock(&qdisc_tree_lock); } else { qdisc = &noqueue_qdisc; } - write_lock(&qdisc_tree_lock); dev->qdisc_sleeping = qdisc; - write_unlock(&qdisc_tree_lock); } if (!netif_carrier_ok(dev)) |