diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-10-15 13:46:29 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-10-15 13:46:29 +0200 |
commit | b2aaf8f74cdc84a9182f6cabf198b7763bcb9d40 (patch) | |
tree | 53ccb1c2c14751fe69cf93102e76e97021f6df07 /net/sched/sch_generic.c | |
parent | 4f962d4d65923d7b722192e729840cfb79af0a5a (diff) | |
parent | 278429cff8809958d25415ba0ed32b59866ab1a8 (diff) |
Merge branch 'linus' into stackprotector
Conflicts:
arch/x86/kernel/Makefile
include/asm-x86/pda.h
Diffstat (limited to 'net/sched/sch_generic.c')
-rw-r--r-- | net/sched/sch_generic.c | 411 |
1 files changed, 248 insertions, 163 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index d355e5e47fe..7b5572d6beb 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -29,71 +29,56 @@ /* Main transmission queue. */ /* Modifications to data participating in scheduling must be protected with - * dev->queue_lock spinlock. + * qdisc_lock(qdisc) 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. + * - enqueue, dequeue are serialized via qdisc root lock + * - ingress filtering is also serialized via qdisc root lock * - updates to tree and tree walking are only done under the rtnl mutex. */ -void qdisc_lock_tree(struct net_device *dev) - __acquires(dev->queue_lock) - __acquires(dev->ingress_lock) -{ - spin_lock_bh(&dev->queue_lock); - spin_lock(&dev->ingress_lock); -} -EXPORT_SYMBOL(qdisc_lock_tree); - -void qdisc_unlock_tree(struct net_device *dev) - __releases(dev->ingress_lock) - __releases(dev->queue_lock) -{ - spin_unlock(&dev->ingress_lock); - spin_unlock_bh(&dev->queue_lock); -} -EXPORT_SYMBOL(qdisc_unlock_tree); - static inline int qdisc_qlen(struct Qdisc *q) { return q->q.qlen; } -static inline int dev_requeue_skb(struct sk_buff *skb, struct net_device *dev, - struct Qdisc *q) +static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) { - if (unlikely(skb->next)) - dev->gso_skb = skb; - else - q->ops->requeue(skb, q); + q->gso_skb = skb; + q->qstats.requeues++; + __netif_schedule(q); - netif_schedule(dev); return 0; } -static inline struct sk_buff *dev_dequeue_skb(struct net_device *dev, - struct Qdisc *q) +static inline struct sk_buff *dequeue_skb(struct Qdisc *q) { - struct sk_buff *skb; + struct sk_buff *skb = q->gso_skb; + + if (unlikely(skb)) { + struct net_device *dev = qdisc_dev(q); + struct netdev_queue *txq; - if ((skb = dev->gso_skb)) - dev->gso_skb = NULL; - else + /* check the reason of requeuing without tx lock first */ + txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); + if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq)) + q->gso_skb = NULL; + else + skb = NULL; + } else { skb = q->dequeue(q); + } return skb; } static inline int handle_dev_cpu_collision(struct sk_buff *skb, - struct net_device *dev, + struct netdev_queue *dev_queue, struct Qdisc *q) { int ret; - if (unlikely(dev->xmit_lock_owner == smp_processor_id())) { + if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) { /* * Same CPU holding the lock. It may be a transient * configuration error, when hard_start_xmit() recurses. We @@ -103,7 +88,7 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb, kfree_skb(skb); if (net_ratelimit()) printk(KERN_WARNING "Dead loop on netdevice %s, " - "fix it urgently!\n", dev->name); + "fix it urgently!\n", dev_queue->dev->name); ret = qdisc_qlen(q); } else { /* @@ -111,22 +96,22 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb, * some time. */ __get_cpu_var(netdev_rx_stat).cpu_collision++; - ret = dev_requeue_skb(skb, dev, q); + ret = dev_requeue_skb(skb, q); } return ret; } /* - * NOTE: Called under dev->queue_lock with locally disabled BH. + * NOTE: Called under qdisc_lock(q) with locally disabled BH. * - * __LINK_STATE_QDISC_RUNNING guarantees only one CPU can process this - * device at a time. dev->queue_lock serializes queue accesses for - * this device AND dev->qdisc pointer itself. + * __QDISC_STATE_RUNNING guarantees only one CPU can process + * this qdisc at a time. qdisc_lock(q) serializes queue accesses for + * this queue. * * netif_tx_lock serializes accesses to device driver. * - * dev->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 @@ -136,27 +121,33 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb, * >0 - queue is not empty. * */ -static inline int qdisc_restart(struct net_device *dev) +static inline int qdisc_restart(struct Qdisc *q) { - struct Qdisc *q = dev->qdisc; - struct sk_buff *skb; + struct netdev_queue *txq; int ret = NETDEV_TX_BUSY; + struct net_device *dev; + spinlock_t *root_lock; + struct sk_buff *skb; /* Dequeue packet */ - if (unlikely((skb = dev_dequeue_skb(dev, q)) == NULL)) + if (unlikely((skb = dequeue_skb(q)) == NULL)) return 0; + root_lock = qdisc_lock(q); - /* And release queue */ - spin_unlock(&dev->queue_lock); + /* And release qdisc */ + spin_unlock(root_lock); - HARD_TX_LOCK(dev, smp_processor_id()); - if (!netif_subqueue_stopped(dev, skb)) - ret = dev_hard_start_xmit(skb, dev); - HARD_TX_UNLOCK(dev); + dev = qdisc_dev(q); + txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); - spin_lock(&dev->queue_lock); - q = dev->qdisc; + HARD_TX_LOCK(dev, txq, smp_processor_id()); + if (!netif_tx_queue_stopped(txq) && + !netif_tx_queue_frozen(txq)) + ret = dev_hard_start_xmit(skb, dev, txq); + HARD_TX_UNLOCK(dev, txq); + + spin_lock(root_lock); switch (ret) { case NETDEV_TX_OK: @@ -166,7 +157,7 @@ static inline int qdisc_restart(struct net_device *dev) case NETDEV_TX_LOCKED: /* Driver try lock failed */ - ret = handle_dev_cpu_collision(skb, dev, q); + ret = handle_dev_cpu_collision(skb, txq, q); break; default: @@ -175,33 +166,34 @@ static inline int qdisc_restart(struct net_device *dev) printk(KERN_WARNING "BUG %s code %d qlen %d\n", dev->name, ret, q->q.qlen); - ret = dev_requeue_skb(skb, dev, q); + ret = dev_requeue_skb(skb, q); break; } + if (ret && (netif_tx_queue_stopped(txq) || + netif_tx_queue_frozen(txq))) + ret = 0; + return ret; } -void __qdisc_run(struct net_device *dev) +void __qdisc_run(struct Qdisc *q) { unsigned long start_time = jiffies; - while (qdisc_restart(dev)) { - if (netif_queue_stopped(dev)) - break; - + while (qdisc_restart(q)) { /* * Postpone processing if * 1. another process needs the CPU; * 2. we've been doing it for too long. */ if (need_resched() || jiffies != start_time) { - netif_schedule(dev); + __netif_schedule(q); break; } } - clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); + clear_bit(__QDISC_STATE_RUNNING, &q->state); } static void dev_watchdog(unsigned long arg) @@ -209,19 +201,34 @@ static void dev_watchdog(unsigned long arg) struct net_device *dev = (struct net_device *)arg; netif_tx_lock(dev); - if (dev->qdisc != &noop_qdisc) { + if (!qdisc_tx_is_noop(dev)) { if (netif_device_present(dev) && netif_running(dev) && netif_carrier_ok(dev)) { - if (netif_queue_stopped(dev) && - time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) { + int some_queue_stopped = 0; + unsigned int i; + + for (i = 0; i < dev->num_tx_queues; i++) { + struct netdev_queue *txq; - printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", - dev->name); + txq = netdev_get_tx_queue(dev, i); + if (netif_tx_queue_stopped(txq)) { + some_queue_stopped = 1; + break; + } + } + + if (some_queue_stopped && + time_after(jiffies, (dev->trans_start + + dev->watchdog_timeo))) { + char drivername[64]; + WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n", + dev->name, netdev_drivername(dev, drivername, 64)); dev->tx_timeout(dev); - WARN_ON_ONCE(1); } - if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) + if (!mod_timer(&dev->watchdog_timer, + round_jiffies(jiffies + + dev->watchdog_timeo))) dev_hold(dev); } } @@ -317,12 +324,19 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = { .owner = THIS_MODULE, }; +static struct netdev_queue noop_netdev_queue = { + .qdisc = &noop_qdisc, +}; + struct Qdisc noop_qdisc = { .enqueue = noop_enqueue, .dequeue = noop_dequeue, .flags = TCQ_F_BUILTIN, .ops = &noop_qdisc_ops, .list = LIST_HEAD_INIT(noop_qdisc.list), + .requeue.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), + .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), + .dev_queue = &noop_netdev_queue, }; EXPORT_SYMBOL(noop_qdisc); @@ -335,12 +349,20 @@ static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = { .owner = THIS_MODULE, }; +static struct Qdisc noqueue_qdisc; +static struct netdev_queue noqueue_netdev_queue = { + .qdisc = &noqueue_qdisc, +}; + static struct Qdisc noqueue_qdisc = { .enqueue = NULL, .dequeue = noop_dequeue, .flags = TCQ_F_BUILTIN, .ops = &noqueue_qdisc_ops, .list = LIST_HEAD_INIT(noqueue_qdisc.list), + .requeue.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), + .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), + .dev_queue = &noqueue_netdev_queue, }; @@ -364,7 +386,7 @@ static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) { struct sk_buff_head *list = prio2list(skb, qdisc); - if (skb_queue_len(list) < qdisc->dev->tx_queue_len) { + if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) { qdisc->q.qlen++; return __qdisc_enqueue_tail(skb, qdisc, list); } @@ -440,7 +462,8 @@ static struct Qdisc_ops pfifo_fast_ops __read_mostly = { .owner = THIS_MODULE, }; -struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) +struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, + struct Qdisc_ops *ops) { void *p; struct Qdisc *sch; @@ -458,28 +481,30 @@ struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) sch->padded = (char *) sch - (char *) p; INIT_LIST_HEAD(&sch->list); + skb_queue_head_init(&sch->requeue); skb_queue_head_init(&sch->q); sch->ops = ops; sch->enqueue = ops->enqueue; sch->dequeue = ops->dequeue; - sch->dev = dev; - dev_hold(dev); + sch->dev_queue = dev_queue; + dev_hold(qdisc_dev(sch)); atomic_set(&sch->refcnt, 1); return sch; errout: - return ERR_PTR(-err); + return ERR_PTR(err); } -struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops, +struct Qdisc * qdisc_create_dflt(struct net_device *dev, + struct netdev_queue *dev_queue, + struct Qdisc_ops *ops, unsigned int parentid) { struct Qdisc *sch; - sch = qdisc_alloc(dev, ops); + sch = qdisc_alloc(dev_queue, ops); if (IS_ERR(sch)) goto errout; - sch->stats_lock = &dev->queue_lock; sch->parent = parentid; if (!ops->init || ops->init(sch, NULL) == 0) @@ -491,7 +516,7 @@ errout: } EXPORT_SYMBOL(qdisc_create_dflt); -/* Under dev->queue_lock and BH! */ +/* Under qdisc_lock(qdisc) and BH! */ void qdisc_reset(struct Qdisc *qdisc) { @@ -502,17 +527,6 @@ void qdisc_reset(struct Qdisc *qdisc) } EXPORT_SYMBOL(qdisc_reset); -/* this is the rcu callback function to clean up a qdisc when there - * are no further references to it */ - -static void __qdisc_destroy(struct rcu_head *head) -{ - struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu); - kfree((char *) qdisc - qdisc->padded); -} - -/* Under dev->queue_lock and BH! */ - void qdisc_destroy(struct Qdisc *qdisc) { const struct Qdisc_ops *ops = qdisc->ops; @@ -521,7 +535,11 @@ void qdisc_destroy(struct Qdisc *qdisc) !atomic_dec_and_test(&qdisc->refcnt)) return; - list_del(&qdisc->list); +#ifdef CONFIG_NET_SCHED + qdisc_list_del(qdisc); + + qdisc_put_stab(qdisc->stab); +#endif gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); if (ops->reset) ops->reset(qdisc); @@ -529,65 +547,141 @@ void qdisc_destroy(struct Qdisc *qdisc) ops->destroy(qdisc); module_put(ops->owner); - dev_put(qdisc->dev); - call_rcu(&qdisc->q_rcu, __qdisc_destroy); + dev_put(qdisc_dev(qdisc)); + + kfree_skb(qdisc->gso_skb); + __skb_queue_purge(&qdisc->requeue); + + kfree((char *) qdisc - qdisc->padded); } EXPORT_SYMBOL(qdisc_destroy); +static bool dev_all_qdisc_sleeping_noop(struct net_device *dev) +{ + unsigned int i; + + for (i = 0; i < dev->num_tx_queues; i++) { + struct netdev_queue *txq = netdev_get_tx_queue(dev, i); + + if (txq->qdisc_sleeping != &noop_qdisc) + return false; + } + return true; +} + +static void attach_one_default_qdisc(struct net_device *dev, + struct netdev_queue *dev_queue, + void *_unused) +{ + struct Qdisc *qdisc; + + if (dev->tx_queue_len) { + qdisc = qdisc_create_dflt(dev, dev_queue, + &pfifo_fast_ops, TC_H_ROOT); + if (!qdisc) { + printk(KERN_INFO "%s: activation failed\n", dev->name); + return; + } + } else { + qdisc = &noqueue_qdisc; + } + dev_queue->qdisc_sleeping = qdisc; +} + +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; + + if (!(new_qdisc->flags & TCQ_F_BUILTIN)) + clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state); + + rcu_assign_pointer(dev_queue->qdisc, new_qdisc); + if (need_watchdog_p && new_qdisc != &noqueue_qdisc) + *need_watchdog_p = 1; +} + void dev_activate(struct net_device *dev) { + int need_watchdog; + /* No queueing discipline is attached to device; create default one i.e. pfifo_fast for devices, which need queueing and noqueue_qdisc for virtual interfaces */ - if (dev->qdisc_sleeping == &noop_qdisc) { - struct Qdisc *qdisc; - if (dev->tx_queue_len) { - qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops, - TC_H_ROOT); - if (qdisc == NULL) { - printk(KERN_INFO "%s: activation failed\n", dev->name); - return; - } - list_add_tail(&qdisc->list, &dev->qdisc_list); - } else { - qdisc = &noqueue_qdisc; - } - dev->qdisc_sleeping = qdisc; - } + if (dev_all_qdisc_sleeping_noop(dev)) + netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); if (!netif_carrier_ok(dev)) /* Delay activation until next carrier-on event */ return; - spin_lock_bh(&dev->queue_lock); - rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping); - if (dev->qdisc != &noqueue_qdisc) { + need_watchdog = 0; + netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog); + transition_one_qdisc(dev, &dev->rx_queue, NULL); + + if (need_watchdog) { dev->trans_start = jiffies; dev_watchdog_up(dev); } - spin_unlock_bh(&dev->queue_lock); } -void dev_deactivate(struct net_device *dev) +static void dev_deactivate_queue(struct net_device *dev, + struct netdev_queue *dev_queue, + void *_qdisc_default) { + struct Qdisc *qdisc_default = _qdisc_default; struct Qdisc *qdisc; - struct sk_buff *skb; - int running; - spin_lock_bh(&dev->queue_lock); - qdisc = dev->qdisc; - dev->qdisc = &noop_qdisc; + qdisc = dev_queue->qdisc; + if (qdisc) { + spin_lock_bh(qdisc_lock(qdisc)); - qdisc_reset(qdisc); + if (!(qdisc->flags & TCQ_F_BUILTIN)) + set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); - skb = dev->gso_skb; - dev->gso_skb = NULL; - spin_unlock_bh(&dev->queue_lock); + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); + qdisc_reset(qdisc); - kfree_skb(skb); + spin_unlock_bh(qdisc_lock(qdisc)); + } +} + +static bool some_qdisc_is_busy(struct net_device *dev) +{ + unsigned int i; + + for (i = 0; i < dev->num_tx_queues; i++) { + struct netdev_queue *dev_queue; + spinlock_t *root_lock; + struct Qdisc *q; + int val; + + dev_queue = netdev_get_tx_queue(dev, i); + q = dev_queue->qdisc_sleeping; + root_lock = qdisc_lock(q); + + spin_lock_bh(root_lock); + + val = (test_bit(__QDISC_STATE_RUNNING, &q->state) || + test_bit(__QDISC_STATE_SCHED, &q->state)); + + spin_unlock_bh(root_lock); + + if (val) + return true; + } + return false; +} + +void dev_deactivate(struct net_device *dev) +{ + netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc); + dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc); dev_watchdog_down(dev); @@ -595,55 +689,46 @@ void dev_deactivate(struct net_device *dev) synchronize_rcu(); /* Wait for outstanding qdisc_run calls. */ - do { - while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state)) - yield(); + while (some_qdisc_is_busy(dev)) + yield(); +} - /* - * Double-check inside queue lock to ensure that all effects - * of the queue run are visible when we return. - */ - spin_lock_bh(&dev->queue_lock); - running = test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); - spin_unlock_bh(&dev->queue_lock); +static void dev_init_scheduler_queue(struct net_device *dev, + struct netdev_queue *dev_queue, + void *_qdisc) +{ + struct Qdisc *qdisc = _qdisc; - /* - * The running flag should never be set at this point because - * we've already set dev->qdisc to noop_qdisc *inside* the same - * pair of spin locks. That is, if any qdisc_run starts after - * our initial test it should see the noop_qdisc and then - * clear the RUNNING bit before dropping the queue lock. So - * if it is set here then we've found a bug. - */ - } while (WARN_ON_ONCE(running)); + dev_queue->qdisc = qdisc; + dev_queue->qdisc_sleeping = qdisc; } void dev_init_scheduler(struct net_device *dev) { - qdisc_lock_tree(dev); - dev->qdisc = &noop_qdisc; - dev->qdisc_sleeping = &noop_qdisc; - INIT_LIST_HEAD(&dev->qdisc_list); - qdisc_unlock_tree(dev); + netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc); + dev_init_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc); setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev); } -void dev_shutdown(struct net_device *dev) +static void shutdown_scheduler_queue(struct net_device *dev, + struct netdev_queue *dev_queue, + void *_qdisc_default) { - struct Qdisc *qdisc; + struct Qdisc *qdisc = dev_queue->qdisc_sleeping; + struct Qdisc *qdisc_default = _qdisc_default; + + if (qdisc) { + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); + dev_queue->qdisc_sleeping = qdisc_default; - qdisc_lock_tree(dev); - qdisc = dev->qdisc_sleeping; - dev->qdisc = &noop_qdisc; - dev->qdisc_sleeping = &noop_qdisc; - qdisc_destroy(qdisc); -#if defined(CONFIG_NET_SCH_INGRESS) || defined(CONFIG_NET_SCH_INGRESS_MODULE) - if ((qdisc = dev->qdisc_ingress) != NULL) { - dev->qdisc_ingress = NULL; qdisc_destroy(qdisc); } -#endif - BUG_TRAP(!timer_pending(&dev->watchdog_timer)); - qdisc_unlock_tree(dev); +} + +void dev_shutdown(struct net_device *dev) +{ + netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc); + shutdown_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc); + WARN_ON(timer_pending(&dev->watchdog_timer)); } |