[PATCH 1/13]: netdev: Allocate multiple queues for TX.

[PATCH 1/13]: netdev: Allocate multiple queues for TX.

[David Miller]

alloc_netdev_mq() now allocates an array of netdev_queue
structures for TX, based upon the queue_count argument.

Furthermore, all accesses to the TX queues are now vectored
through the netdev_get_tx_queue() and netdev_for_each_tx_queue()
interfaces.  This makes it easy to grep the tree for all
things that want to get to a TX queue of a net device.

Problem spots which are not really multiqueue aware yet, and
only work with one queue, can easily be spotted by grepping
for all netdev_get_tx_queue() calls that pass in a zero index.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/bonding/bond_main.c         |    6 +-
 drivers/net/hamradio/bpqether.c         |    6 +-
 drivers/net/ifb.c                       |   12 ++-
 drivers/net/macvlan.c                   |    6 +-
 drivers/net/wireless/hostap/hostap_hw.c |    6 +-
 include/linux/netdevice.h               |   67 ++++++++----
 include/net/sch_generic.h               |   37 +++++--
 net/8021q/vlan_dev.c                    |   10 +-
 net/core/dev.c                          |   40 ++++++--
 net/core/rtnetlink.c                    |    2 +-
 net/mac80211/main.c                     |    4 +-
 net/mac80211/wme.c                      |   12 +-
 net/netrom/af_netrom.c                  |    6 +-
 net/rose/af_rose.c                      |    6 +-
 net/sched/cls_api.c                     |    4 +-
 net/sched/sch_api.c                     |   32 ++++--
 net/sched/sch_generic.c                 |  178 ++++++++++++++++++++++--------
 net/sched/sch_teql.c                    |   21 +++--
 18 files changed, 319 insertions(+), 136 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index dc733d7..9ed520b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -5019,7 +5019,9 @@ static int bond_check_params(struct bond_params *params)
 
 static struct lock_class_key bonding_netdev_xmit_lock_key;
 
-static void bond_set_lockdep_class_one(struct netdev_queue *txq)
+static void bond_set_lockdep_class_one(struct net_device *dev,
+				       struct netdev_queue *txq,
+				       void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock,
 			  &bonding_netdev_xmit_lock_key);
@@ -5027,7 +5029,7 @@ static void bond_set_lockdep_class_one(struct netdev_queue *txq)
 
 static void bond_set_lockdep_class(struct net_device *dev)
 {
-	bond_set_lockdep_class_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, bond_set_lockdep_class_one, NULL);
 }
 
 /* Create a new bond based on the specified name and bonding parameters.
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index fb186b8..b6500b2 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -124,14 +124,16 @@ static LIST_HEAD(bpq_devices);
  */
 static struct lock_class_key bpq_netdev_xmit_lock_key;
 
-static void bpq_set_lockdep_class_one(struct netdev_queue *txq)
+static void bpq_set_lockdep_class_one(struct net_device *dev,
+				      struct netdev_queue *txq,
+				      void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
 }
 
 static void bpq_set_lockdep_class(struct net_device *dev)
 {
-	bpq_set_lockdep_class_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
 }
 
 /* ------------------------------------------------------------------------ */
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index ccbd655..897b05e 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -229,14 +229,20 @@ module_param(numifbs, int, 0);
 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
 
 /*
- * dev_ifb->tx_queue.lock is usually taken after dev->rx_queue.lock,
+ * 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->tx_queue.lock with dev_ifb->rx_queue.lock.
+ * 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)
 {
@@ -258,7 +264,7 @@ static int __init ifb_init_one(int index)
 	if (err < 0)
 		goto err;
 
-	lockdep_set_class(&dev_ifb->tx_queue.lock, &ifb_tx_queue_lock_key);
+	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;
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index c02ceaa..13dea95 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -277,7 +277,9 @@ static struct lock_class_key macvlan_netdev_xmit_lock_key;
 #define MACVLAN_STATE_MASK \
 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 
-static void macvlan_set_lockdep_class_one(struct netdev_queue *txq)
+static void macvlan_set_lockdep_class_one(struct net_device *dev,
+					  struct netdev_queue *txq,
+					  void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock,
 			  &macvlan_netdev_xmit_lock_key);
@@ -285,7 +287,7 @@ static void macvlan_set_lockdep_class_one(struct netdev_queue *txq)
 
 static void macvlan_set_lockdep_class(struct net_device *dev)
 {
-	macvlan_set_lockdep_class_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
 }
 
 static int macvlan_init(struct net_device *dev)
diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index c1f4bb0..13d5882 100644
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -3102,7 +3102,9 @@ static void prism2_clear_set_tim_queue(local_info_t *local)
  */
 static struct lock_class_key hostap_netdev_xmit_lock_key;
 
-static void prism2_set_lockdep_class_one(struct netdev_queue *txq)
+static void prism2_set_lockdep_class_one(struct net_device *dev,
+					 struct netdev_queue *txq,
+					 void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock,
 			  &hostap_netdev_xmit_lock_key);
@@ -3110,7 +3112,7 @@ static void prism2_set_lockdep_class_one(struct netdev_queue *txq)
 
 static void prism2_set_lockdep_class(struct net_device *dev)
 {
-	prism2_set_lockdep_class_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, prism2_set_lockdep_class_one, NULL);
 }
 
 static struct net_device *
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 203c550..2502a84 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -640,7 +640,9 @@ struct net_device
 	unsigned char		broadcast[MAX_ADDR_LEN];	/* hw bcast add	*/
 
 	struct netdev_queue	rx_queue;
-	struct netdev_queue	tx_queue ____cacheline_aligned_in_smp;
+
+	struct netdev_queue	*_tx;
+	unsigned int		num_tx_queues;
 	unsigned long		tx_queue_len;	/* Max frames per queue allowed */
 
 /*
@@ -763,6 +765,25 @@ struct net_device
 #define	NETDEV_ALIGN		32
 #define	NETDEV_ALIGN_CONST	(NETDEV_ALIGN - 1)
 
+static inline
+struct netdev_queue *netdev_get_tx_queue(const struct net_device *dev,
+					 unsigned int index)
+{
+	return &dev->_tx[index];
+}
+
+static inline void netdev_for_each_tx_queue(struct net_device *dev,
+					    void (*f)(struct net_device *,
+						      struct netdev_queue *,
+						      void *),
+					    void *arg)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++)
+		f(dev, &dev->_tx[i], arg);
+}
+
 /*
  * Net namespace inlines
  */
@@ -963,7 +984,7 @@ static inline void netif_schedule_queue(struct netdev_queue *txq)
 
 static inline void netif_schedule(struct net_device *dev)
 {
-	netif_schedule_queue(&dev->tx_queue);
+	netif_schedule_queue(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -979,7 +1000,7 @@ static inline void netif_tx_start_queue(struct netdev_queue *dev_queue)
 
 static inline void netif_start_queue(struct net_device *dev)
 {
-	netif_tx_start_queue(&dev->tx_queue);
+	netif_tx_start_queue(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -1003,7 +1024,7 @@ static inline void netif_tx_wake_queue(struct netdev_queue *dev_queue)
 
 static inline void netif_wake_queue(struct net_device *dev)
 {
-	netif_tx_wake_queue(&dev->tx_queue);
+	netif_tx_wake_queue(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -1020,7 +1041,7 @@ static inline void netif_tx_stop_queue(struct netdev_queue *dev_queue)
 
 static inline void netif_stop_queue(struct net_device *dev)
 {
-	netif_tx_stop_queue(&dev->tx_queue);
+	netif_tx_stop_queue(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -1036,7 +1057,7 @@ static inline int netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
 
 static inline int netif_queue_stopped(const struct net_device *dev)
 {
-	return netif_tx_queue_stopped(&dev->tx_queue);
+	return netif_tx_queue_stopped(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -1120,7 +1141,7 @@ static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
 #endif
 	if (test_and_clear_bit(__QUEUE_STATE_XOFF,
 			       &dev->egress_subqueue[queue_index].state))
-		__netif_schedule(&dev->tx_queue);
+		__netif_schedule(netdev_get_tx_queue(dev, 0));
 }
 
 /**
@@ -1415,18 +1436,19 @@ static inline void __netif_tx_lock(struct netdev_queue *txq, int cpu)
 
 static inline void netif_tx_lock(struct net_device *dev)
 {
-	__netif_tx_lock(&dev->tx_queue, smp_processor_id());
-}
+	int cpu = smp_processor_id();
+	unsigned int i;
 
-static inline void __netif_tx_lock_bh(struct netdev_queue *txq)
-{
-	spin_lock_bh(&txq->_xmit_lock);
-	txq->xmit_lock_owner = smp_processor_id();
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		__netif_tx_lock(txq, cpu);
+	}
 }
 
 static inline void netif_tx_lock_bh(struct net_device *dev)
 {
-	__netif_tx_lock_bh(&dev->tx_queue);
+	local_bh_disable();
+	netif_tx_lock(dev);
 }
 
 static inline int __netif_tx_trylock(struct netdev_queue *txq)
@@ -1439,7 +1461,7 @@ static inline int __netif_tx_trylock(struct netdev_queue *txq)
 
 static inline int netif_tx_trylock(struct net_device *dev)
 {
-	return __netif_tx_trylock(&dev->tx_queue);
+	return __netif_tx_trylock(netdev_get_tx_queue(dev, 0));
 }
 
 static inline void __netif_tx_unlock(struct netdev_queue *txq)
@@ -1450,18 +1472,19 @@ static inline void __netif_tx_unlock(struct netdev_queue *txq)
 
 static inline void netif_tx_unlock(struct net_device *dev)
 {
-	__netif_tx_unlock(&dev->tx_queue);
-}
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		__netif_tx_unlock(txq);
+	}
 
-static inline void __netif_tx_unlock_bh(struct netdev_queue *txq)
-{
-	txq->xmit_lock_owner = -1;
-	spin_unlock_bh(&txq->_xmit_lock);
 }
 
 static inline void netif_tx_unlock_bh(struct net_device *dev)
 {
-	__netif_tx_unlock_bh(&dev->tx_queue);
+	netif_tx_unlock(dev);
+	local_bh_enable();
 }
 
 #define HARD_TX_LOCK(dev, txq, cpu) {			\
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 5ba66b5..b47f556 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -230,32 +230,47 @@ extern void tcf_destroy_chain(struct tcf_proto **fl);
 /* Reset all TX qdiscs of a device.  */
 static inline void qdisc_reset_all_tx(struct net_device *dev)
 {
-	qdisc_reset(dev->tx_queue.qdisc);
+	unsigned int i;
+	for (i = 0; i < dev->num_tx_queues; i++)
+		qdisc_reset(netdev_get_tx_queue(dev, i)->qdisc);
 }
 
 /* Are all TX queues of the device empty?  */
 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 {
-	const struct netdev_queue *txq = &dev->tx_queue;
-	const struct Qdisc *q = txq->qdisc;
+	unsigned int i;
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		const struct Qdisc *q = txq->qdisc;
 
-	return (q->q.qlen == 0);
+		if (q->q.qlen)
+			return false;
+	}
+	return true;
 }
 
 /* Are any of the TX qdiscs changing?  */
 static inline bool qdisc_tx_changing(struct net_device *dev)
 {
-	struct netdev_queue *txq = &dev->tx_queue;
-
-	return (txq->qdisc != txq->qdisc_sleeping);
+	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 != txq->qdisc_sleeping)
+			return true;
+	}
+	return false;
 }
 
-/* Is the device using the noop qdisc?  */
+/* Is the device using the noop qdisc on all queues?  */
 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 {
-	const struct netdev_queue *txq = &dev->tx_queue;
-
-	return (txq->qdisc == &noop_qdisc);
+	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 != &noop_qdisc)
+			return false;
+	}
+	return true;
 }
 
 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 8efa399..96bc7ef 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -627,16 +627,18 @@ static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
  */
 static struct lock_class_key vlan_netdev_xmit_lock_key;
 
-static void vlan_dev_set_lockdep_one(struct netdev_queue *txq,
-				     int subclass)
+static void vlan_dev_set_lockdep_one(struct net_device *dev,
+				     struct netdev_queue *txq,
+				     void *_subclass)
 {
 	lockdep_set_class_and_subclass(&txq->_xmit_lock,
-				       &vlan_netdev_xmit_lock_key, subclass);
+				       &vlan_netdev_xmit_lock_key,
+				       *(int *)_subclass);
 }
 
 static void vlan_dev_set_lockdep_class(struct net_device *dev, int subclass)
 {
-	vlan_dev_set_lockdep_one(&dev->tx_queue, subclass);
+	netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, &subclass);
 }
 
 static const struct header_ops vlan_header_ops = {
diff --git a/net/core/dev.c b/net/core/dev.c
index a29a359..0fd454f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1666,6 +1666,12 @@ out_kfree_skb:
  *          --BLG
  */
 
+static struct netdev_queue *dev_pick_tx(struct net_device *dev,
+					struct sk_buff *skb)
+{
+	return netdev_get_tx_queue(dev, 0);
+}
+
 int dev_queue_xmit(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
@@ -1702,7 +1708,7 @@ int dev_queue_xmit(struct sk_buff *skb)
 	}
 
 gso:
-	txq = &dev->tx_queue;
+	txq = dev_pick_tx(dev, skb);
 	spin_lock_prefetch(&txq->lock);
 
 	/* Disable soft irqs for various locks below. Also
@@ -3761,8 +3767,9 @@ static void rollback_registered(struct net_device *dev)
 	dev_put(dev);
 }
 
-static void __netdev_init_queue_locks_one(struct netdev_queue *dev_queue,
-					  struct net_device *dev)
+static void __netdev_init_queue_locks_one(struct net_device *dev,
+					  struct netdev_queue *dev_queue,
+					  void *_unused)
 {
 	spin_lock_init(&dev_queue->_xmit_lock);
 	netdev_set_lockdep_class(&dev_queue->_xmit_lock, dev->type);
@@ -3771,8 +3778,8 @@ static void __netdev_init_queue_locks_one(struct netdev_queue *dev_queue,
 
 static void netdev_init_queue_locks(struct net_device *dev)
 {
-	__netdev_init_queue_locks_one(&dev->tx_queue, dev);
-	__netdev_init_queue_locks_one(&dev->rx_queue, dev);
+	netdev_for_each_tx_queue(dev, __netdev_init_queue_locks_one, NULL);
+	__netdev_init_queue_locks_one(dev, &dev->rx_queue, NULL);
 }
 
 /**
@@ -4091,7 +4098,8 @@ static struct net_device_stats *internal_stats(struct net_device *dev)
 }
 
 static void netdev_init_one_queue(struct net_device *dev,
-				  struct netdev_queue *queue)
+				  struct netdev_queue *queue,
+				  void *_unused)
 {
 	spin_lock_init(&queue->lock);
 	queue->dev = dev;
@@ -4099,8 +4107,8 @@ static void netdev_init_one_queue(struct net_device *dev,
 
 static void netdev_init_queues(struct net_device *dev)
 {
-	netdev_init_one_queue(dev, &dev->rx_queue);
-	netdev_init_one_queue(dev, &dev->tx_queue);
+	netdev_init_one_queue(dev, &dev->rx_queue, NULL);
+	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
 }
 
 /**
@@ -4117,9 +4125,10 @@ static void netdev_init_queues(struct net_device *dev)
 struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
 		void (*setup)(struct net_device *), unsigned int queue_count)
 {
-	void *p;
+	struct netdev_queue *tx;
 	struct net_device *dev;
 	int alloc_size;
+	void *p;
 
 	BUG_ON(strlen(name) >= sizeof(dev->name));
 
@@ -4139,11 +4148,22 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
 		return NULL;
 	}
 
+	tx = kzalloc(sizeof(struct netdev_queue) * queue_count, GFP_KERNEL);
+	if (!tx) {
+		printk(KERN_ERR "alloc_netdev: Unable to allocate "
+		       "tx qdiscs.\n");
+		kfree(p);
+		return NULL;
+	}
+
 	dev = (struct net_device *)
 		(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
 	dev->padded = (char *)dev - (char *)p;
 	dev_net_set(dev, &init_net);
 
+	dev->_tx = tx;
+	dev->num_tx_queues = queue_count;
+
 	if (sizeof_priv) {
 		dev->priv = ((char *)dev +
 			     ((sizeof(struct net_device) +
@@ -4177,6 +4197,8 @@ void free_netdev(struct net_device *dev)
 {
 	release_net(dev_net(dev));
 
+	kfree(dev->_tx);
+
 	/*  Compatibility with error handling in drivers */
 	if (dev->reg_state == NETREG_UNINITIALIZED) {
 		kfree((char *)dev - dev->padded);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 8ef9f1d..71edb8b 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -636,7 +636,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	if (dev->master)
 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
 
-	txq = &dev->tx_queue;
+	txq = netdev_get_tx_queue(dev, 0);
 	if (txq->qdisc_sleeping)
 		NLA_PUT_STRING(skb, IFLA_QDISC, txq->qdisc_sleeping->ops->id);
 
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 1c4d3ba..0ba0e60 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -637,7 +637,7 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 
 	/* ensure that TX flow won't interrupt us
 	 * until the end of the call to requeue function */
-	txq = &local->mdev->tx_queue;
+	txq = netdev_get_tx_queue(local->mdev, 0);
 	spin_lock_bh(&txq->lock);
 
 	/* create a new queue for this aggregation */
@@ -878,7 +878,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 
 	/* avoid ordering issues: we are the only one that can modify
 	 * the content of the qdiscs */
-	txq = &local->mdev->tx_queue;
+	txq = netdev_get_tx_queue(local->mdev, 0);
 	spin_lock_bh(&txq->lock);
 	/* remove the queue for this aggregation */
 	ieee80211_ht_agg_queue_remove(local, sta, tid, 1);
diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 6ae43a3..f014cd3 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -574,7 +574,7 @@ static struct Qdisc_ops wme_qdisc_ops __read_mostly =
 
 void ieee80211_install_qdisc(struct net_device *dev)
 {
-	struct netdev_queue *txq = &dev->tx_queue;
+	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
 	struct Qdisc *qdisc;
 
 	qdisc = qdisc_create_dflt(dev, txq,
@@ -596,7 +596,7 @@ void ieee80211_install_qdisc(struct net_device *dev)
 
 int ieee80211_qdisc_installed(struct net_device *dev)
 {
-	struct netdev_queue *txq = &dev->tx_queue;
+	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
 
 	return txq->qdisc_sleeping->ops == &wme_qdisc_ops;
 }
@@ -617,7 +617,7 @@ int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 			struct sta_info *sta, u16 tid)
 {
 	int i;
-	struct netdev_queue *txq = &local->mdev->tx_queue;
+	struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, 0);
 	struct ieee80211_sched_data *q =
 			qdisc_priv(txq->qdisc_sleeping);
 	DECLARE_MAC_BUF(mac);
@@ -652,14 +652,14 @@ int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 }
 
 /**
- * the caller needs to hold local->mdev->tx_queue.lock
+ * the caller needs to hold netdev_get_tx_queue(local->mdev, X)->lock
  */
 void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
 				   struct sta_info *sta, u16 tid,
 				   u8 requeue)
 {
 	struct ieee80211_hw *hw = &local->hw;
-	struct netdev_queue *txq = &local->mdev->tx_queue;
+	struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, 0);
 	struct ieee80211_sched_data *q =
 		qdisc_priv(txq->qdisc_sleeping);
 	int agg_queue = sta->tid_to_tx_q[tid];
@@ -676,7 +676,7 @@ void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
 
 void ieee80211_requeue(struct ieee80211_local *local, int queue)
 {
-	struct netdev_queue *txq = &local->mdev->tx_queue;
+	struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, 0);
 	struct Qdisc *root_qd = txq->qdisc_sleeping;
 	struct ieee80211_sched_data *q = qdisc_priv(root_qd);
 	struct Qdisc *qdisc = q->queues[queue];
diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 819afc4..d41be0d 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -74,14 +74,16 @@ static const struct proto_ops nr_proto_ops;
  */
 static struct lock_class_key nr_netdev_xmit_lock_key;
 
-static void nr_set_lockdep_one(struct netdev_queue *txq)
+static void nr_set_lockdep_one(struct net_device *dev,
+			       struct netdev_queue *txq,
+			       void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
 }
 
 static void nr_set_lockdep_key(struct net_device *dev)
 {
-	nr_set_lockdep_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
 }
 
 /*
diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 7dbbc08..f3a691f 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -75,14 +75,16 @@ ax25_address rose_callsign;
  */
 static struct lock_class_key rose_netdev_xmit_lock_key;
 
-static void rose_set_lockdep_one(struct netdev_queue *txq)
+static void rose_set_lockdep_one(struct net_device *dev,
+				 struct netdev_queue *txq,
+				 void *_unused)
 {
 	lockdep_set_class(&txq->_xmit_lock, &rose_netdev_xmit_lock_key);
 }
 
 static void rose_set_lockdep_key(struct net_device *dev)
 {
-	rose_set_lockdep_one(&dev->tx_queue);
+	netdev_for_each_tx_queue(dev, rose_set_lockdep_one, NULL);
 }
 
 /*
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index b483bbe..d0b0a9b 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -166,7 +166,7 @@ replay:
 
 	/* Find qdisc */
 	if (!parent) {
-		struct netdev_queue *dev_queue = &dev->tx_queue;
+		struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
 		q = dev_queue->qdisc_sleeping;
 		parent = q->handle;
 	} else {
@@ -410,7 +410,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
 		return skb->len;
 
-	dev_queue = &dev->tx_queue;
+	dev_queue = netdev_get_tx_queue(dev, 0);
 	if (!tcm->tcm_parent)
 		q = dev_queue->qdisc_sleeping;
 	else
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 95873f8..830ccc5 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -183,9 +183,8 @@ EXPORT_SYMBOL(unregister_qdisc);
    (root qdisc, all its children, children of children etc.)
  */
 
-struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
+static struct Qdisc *__qdisc_lookup(struct netdev_queue *dev_queue, u32 handle)
 {
-	struct netdev_queue *dev_queue = &dev->tx_queue;
 	struct Qdisc *q;
 
 	list_for_each_entry(q, &dev_queue->qdisc_list, list) {
@@ -195,6 +194,19 @@ struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
 	return NULL;
 }
 
+struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		struct Qdisc *q = __qdisc_lookup(txq, handle);
+		if (q)
+			return q;
+	}
+	return NULL;
+}
+
 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 {
 	unsigned long cl;
@@ -462,7 +474,7 @@ dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc)
 		}
 
 	} else {
-		dev_queue = &dev->tx_queue;
+		dev_queue = netdev_get_tx_queue(dev, 0);
 		oqdisc = dev_queue->qdisc_sleeping;
 
 		/* Prune old scheduler */
@@ -742,7 +754,8 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 				q = dev->rx_queue.qdisc;
 			}
 		} else {
-			struct netdev_queue *dev_queue = &dev->tx_queue;
+			struct netdev_queue *dev_queue;
+			dev_queue = netdev_get_tx_queue(dev, 0);
 			q = dev_queue->qdisc_sleeping;
 		}
 		if (!q)
@@ -817,7 +830,8 @@ replay:
 				q = dev->rx_queue.qdisc;
 			}
 		} else {
-			struct netdev_queue *dev_queue = &dev->tx_queue;
+			struct netdev_queue *dev_queue;
+			dev_queue = netdev_get_tx_queue(dev, 0);
 			q = dev_queue->qdisc_sleeping;
 		}
 
@@ -899,7 +913,7 @@ create_n_graft:
 				 tcm->tcm_parent, tcm->tcm_parent,
 				 tca, &err);
 	else
-		q = qdisc_create(dev, &dev->tx_queue,
+		q = qdisc_create(dev, netdev_get_tx_queue(dev, 0),
 				 tcm->tcm_parent, tcm->tcm_handle,
 				 tca, &err);
 	if (q == NULL) {
@@ -1025,7 +1039,7 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 		if (idx > s_idx)
 			s_q_idx = 0;
 		q_idx = 0;
-		dev_queue = &dev->tx_queue;
+		dev_queue = netdev_get_tx_queue(dev, 0);
 		list_for_each_entry(q, &dev_queue->qdisc_list, list) {
 			if (q_idx < s_q_idx) {
 				q_idx++;
@@ -1098,7 +1112,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 
 	/* Step 1. Determine qdisc handle X:0 */
 
-	dev_queue = &dev->tx_queue;
+	dev_queue = netdev_get_tx_queue(dev, 0);
 	if (pid != TC_H_ROOT) {
 		u32 qid1 = TC_H_MAJ(pid);
 
@@ -1275,7 +1289,7 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
 	s_t = cb->args[0];
 	t = 0;
 
-	dev_queue = &dev->tx_queue;
+	dev_queue = netdev_get_tx_queue(dev, 0);
 	list_for_each_entry(q, &dev_queue->qdisc_list, list) {
 		if (t < s_t || !q->ops->cl_ops ||
 		    (tcm->tcm_parent &&
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 243de93..4e2b865 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -40,20 +40,30 @@
  */
 
 void qdisc_lock_tree(struct net_device *dev)
-	__acquires(dev->tx_queue.lock)
 	__acquires(dev->rx_queue.lock)
 {
-	spin_lock_bh(&dev->tx_queue.lock);
+	unsigned int i;
+
+	local_bh_disable();
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		spin_lock(&txq->lock);
+	}
 	spin_lock(&dev->rx_queue.lock);
 }
 EXPORT_SYMBOL(qdisc_lock_tree);
 
 void qdisc_unlock_tree(struct net_device *dev)
 	__releases(dev->rx_queue.lock)
-	__releases(dev->tx_queue.lock)
 {
+	unsigned int i;
+
 	spin_unlock(&dev->rx_queue.lock);
-	spin_unlock_bh(&dev->tx_queue.lock);
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+		spin_unlock(&txq->lock);
+	}
+	local_bh_enable();
 }
 EXPORT_SYMBOL(qdisc_unlock_tree);
 
@@ -212,22 +222,37 @@ void __qdisc_run(struct netdev_queue *txq)
 static void dev_watchdog(unsigned long arg)
 {
 	struct net_device *dev = (struct net_device *)arg;
-	struct netdev_queue *txq = &dev->tx_queue;
 
 	netif_tx_lock(dev);
-	if (txq->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;
+
+				txq = netdev_get_tx_queue(dev, i);
+				if (netif_tx_queue_stopped(txq)) {
+					some_queue_stopped = 1;
+					break;
+				}
+			}
 
-				printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n",
+			if (some_queue_stopped &&
+			    time_after(jiffies, (dev->trans_start +
+						 dev->watchdog_timeo))) {
+				printk(KERN_INFO "NETDEV WATCHDOG: %s: "
+				       "transmit timed out\n",
 				       dev->name);
 				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);
 		}
 	}
@@ -542,9 +567,55 @@ void qdisc_destroy(struct Qdisc *qdisc)
 }
 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;
+		}
+		list_add_tail(&qdisc->list, &dev_queue->qdisc_list);
+	} 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)
+{
+	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)
+		*need_watchdog_p = 1;
+	spin_unlock_bh(&dev_queue->lock);
+}
+
 void dev_activate(struct net_device *dev)
 {
-	struct netdev_queue *txq = &dev->tx_queue;
+	int need_watchdog;
 
 	/* No queueing discipline is attached to device;
 	   create default one i.e. pfifo_fast for devices,
@@ -552,39 +623,27 @@ void dev_activate(struct net_device *dev)
 	   virtual interfaces
 	 */
 
-	if (txq->qdisc_sleeping == &noop_qdisc) {
-		struct Qdisc *qdisc;
-		if (dev->tx_queue_len) {
-			qdisc = qdisc_create_dflt(dev, txq,
-						  &pfifo_fast_ops,
-						  TC_H_ROOT);
-			if (qdisc == NULL) {
-				printk(KERN_INFO "%s: activation failed\n", dev->name);
-				return;
-			}
-			list_add_tail(&qdisc->list, &txq->qdisc_list);
-		} else {
-			qdisc =  &noqueue_qdisc;
-		}
-		txq->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(&txq->lock);
-	rcu_assign_pointer(txq->qdisc, txq->qdisc_sleeping);
-	if (txq->qdisc != &noqueue_qdisc) {
+	need_watchdog = 0;
+	netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
+
+	if (need_watchdog) {
 		dev->trans_start = jiffies;
 		dev_watchdog_up(dev);
 	}
-	spin_unlock_bh(&txq->lock);
 }
 
-static void dev_deactivate_queue(struct netdev_queue *dev_queue,
-				 struct Qdisc *qdisc_default)
+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;
 
@@ -603,12 +662,35 @@ static void dev_deactivate_queue(struct netdev_queue *dev_queue,
 	kfree_skb(skb);
 }
 
+static bool some_qdisc_is_running(struct net_device *dev, int lock)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *dev_queue;
+		int val;
+
+		dev_queue = netdev_get_tx_queue(dev, i);
+
+		if (lock)
+			spin_lock_bh(&dev_queue->lock);
+
+		val = test_bit(__QUEUE_STATE_QDISC_RUNNING, &dev_queue->state);
+
+		if (lock)
+			spin_unlock_bh(&dev_queue->lock);
+
+		if (val)
+			return true;
+	}
+	return false;
+}
+
 void dev_deactivate(struct net_device *dev)
 {
-	struct netdev_queue *dev_queue = &dev->tx_queue;
-	int running;
+	bool running;
 
-	dev_deactivate_queue(dev_queue, &noop_qdisc);
+	netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc);
 
 	dev_watchdog_down(dev);
 
@@ -617,17 +699,14 @@ void dev_deactivate(struct net_device *dev)
 
 	/* Wait for outstanding qdisc_run calls. */
 	do {
-		while (test_bit(__QUEUE_STATE_QDISC_RUNNING, &dev_queue->state))
+		while (some_qdisc_is_running(dev, 0))
 			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(__QUEUE_STATE_QDISC_RUNNING,
-				   &dev_queue->state);
-		spin_unlock_bh(&dev_queue->lock);
+		running = some_qdisc_is_running(dev, 1);
 
 		/*
 		 * The running flag should never be set at this point because
@@ -642,8 +721,10 @@ void dev_deactivate(struct net_device *dev)
 
 static void dev_init_scheduler_queue(struct net_device *dev,
 				     struct netdev_queue *dev_queue,
-				     struct Qdisc *qdisc)
+				     void *_qdisc)
 {
+	struct Qdisc *qdisc = _qdisc;
+
 	dev_queue->qdisc = qdisc;
 	dev_queue->qdisc_sleeping = qdisc;
 	INIT_LIST_HEAD(&dev_queue->qdisc_list);
@@ -652,18 +733,19 @@ static void dev_init_scheduler_queue(struct net_device *dev,
 void dev_init_scheduler(struct net_device *dev)
 {
 	qdisc_lock_tree(dev);
-	dev_init_scheduler_queue(dev, &dev->tx_queue, &noop_qdisc);
+	netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
 	dev_init_scheduler_queue(dev, &dev->rx_queue, NULL);
 	qdisc_unlock_tree(dev);
 
 	setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
 }
 
-static void dev_shutdown_scheduler_queue(struct net_device *dev,
-					 struct netdev_queue *dev_queue,
-					 struct Qdisc *qdisc_default)
+static void shutdown_scheduler_queue(struct net_device *dev,
+				     struct netdev_queue *dev_queue,
+				     void *_qdisc_default)
 {
 	struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
+	struct Qdisc *qdisc_default = _qdisc_default;
 
 	if (qdisc) {
 		dev_queue->qdisc = qdisc_default;
@@ -676,8 +758,8 @@ static void dev_shutdown_scheduler_queue(struct net_device *dev,
 void dev_shutdown(struct net_device *dev)
 {
 	qdisc_lock_tree(dev);
-	dev_shutdown_scheduler_queue(dev, &dev->tx_queue, &noop_qdisc);
-	dev_shutdown_scheduler_queue(dev, &dev->rx_queue, NULL);
+	netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
+	shutdown_scheduler_queue(dev, &dev->rx_queue, NULL);
 	BUG_TRAP(!timer_pending(&dev->watchdog_timer));
 	qdisc_unlock_tree(dev);
 }
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index 8ac0598..44a2c34 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -111,7 +111,7 @@ teql_dequeue(struct Qdisc* sch)
 	struct sk_buff *skb;
 
 	skb = __skb_dequeue(&dat->q);
-	dat_queue = &dat->m->dev->tx_queue;
+	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
 	if (skb == NULL) {
 		struct net_device *m = qdisc_dev(dat_queue->qdisc);
 		if (m) {
@@ -155,10 +155,13 @@ teql_destroy(struct Qdisc* sch)
 				if (q == master->slaves) {
 					master->slaves = NEXT_SLAVE(q);
 					if (q == master->slaves) {
+						struct netdev_queue *txq;
+
+						txq = netdev_get_tx_queue(master->dev, 0);
 						master->slaves = NULL;
-						spin_lock_bh(&master->dev->tx_queue.lock);
-						qdisc_reset(master->dev->tx_queue.qdisc);
-						spin_unlock_bh(&master->dev->tx_queue.lock);
+						spin_lock_bh(&txq->lock);
+						qdisc_reset(txq->qdisc);
+						spin_unlock_bh(&txq->lock);
 					}
 				}
 				skb_queue_purge(&dat->q);
@@ -218,7 +221,8 @@ static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt)
 static int
 __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev)
 {
-	struct teql_sched_data *q = qdisc_priv(dev->tx_queue.qdisc);
+	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
+	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
 	struct neighbour *mn = skb->dst->neighbour;
 	struct neighbour *n = q->ncache;
 
@@ -254,7 +258,8 @@ __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *
 static inline int teql_resolve(struct sk_buff *skb,
 			       struct sk_buff *skb_res, struct net_device *dev)
 {
-	if (dev->tx_queue.qdisc == &noop_qdisc)
+	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
+	if (txq->qdisc == &noop_qdisc)
 		return -ENODEV;
 
 	if (dev->header_ops == NULL ||
@@ -285,8 +290,10 @@ restart:
 
 	do {
 		struct net_device *slave = qdisc_dev(q);
+		struct netdev_queue *slave_txq;
 
-		if (slave->tx_queue.qdisc_sleeping != q)
+		slave_txq = netdev_get_tx_queue(slave, 0);
+		if (slave_txq->qdisc_sleeping != q)
 			continue;
 		if (netif_queue_stopped(slave) ||
 		    __netif_subqueue_stopped(slave, subq) ||
-- 
1.5.6.2.255.gbed62

Re: [PATCH 1/13]: netdev: Allocate multiple queues for TX.

[Eric Dumazet]

David Miller a écrit :
> alloc_netdev_mq() now allocates an array of netdev_queue
> structures for TX, based upon the queue_count argument.
> 
> Furthermore, all accesses to the TX queues are now vectored
> through the netdev_get_tx_queue() and netdev_for_each_tx_queue()
> interfaces.  This makes it easy to grep the tree for all
> things that want to get to a TX queue of a net device.
> 
> Problem spots which are not really multiqueue aware yet, and
> only work with one queue, can easily be spotted by grepping
> for all netdev_get_tx_queue() calls that pass in a zero index.
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
> ---

>  	}
>  
> +	tx = kzalloc(sizeof(struct netdev_queue) * queue_count, GFP_KERNEL);
> +	if (!tx) {
> +		printk(KERN_ERR "alloc_netdev: Unable to allocate "
> +		       "tx qdiscs.\n");
> +		kfree(p);
> +		return NULL;
> +	}
> +


On i386 for example, sizeof(struct netdev_queue) = 0x2c

Shouldnt we make sure each queue sits on its own cache line on CONFIG_SMP ?

Also, dev->_tx and dev->num_tx_queues might share a cache line with dev->rx_queue, was it intended ?

> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -640,7 +640,9 @@ struct net_device
>  	unsigned char		broadcast[MAX_ADDR_LEN];	/* hw bcast add	*/
>  
>  	struct netdev_queue	rx_queue;
> -	struct netdev_queue	tx_queue ____cacheline_aligned_in_smp;
> +
> +	struct netdev_queue	*_tx;
> +	unsigned int		num_tx_queues;
>  	unsigned long		tx_queue_len;	/* Max frames per queue allowed */
 

Re: [PATCH 1/13]: netdev: Allocate multiple queues for TX.

[David Miller]

From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 11 Jul 2008 23:19:39 +0200

> On i386 for example, sizeof(struct netdev_queue) = 0x2c
> 
> Shouldnt we make sure each queue sits on its own cache line on CONFIG_SMP ?

Yes.

> Also, dev->_tx and dev->num_tx_queues might share a cache line with
> dev->rx_queue, was it intended ?

Nope.

I've added the ____cacheline_aligned_in_smp annotations to my
tree, thanks!

@@ -463,7 +463,7 @@ struct netdev_queue {
 	struct Qdisc		*qdisc_sleeping;
 	struct list_head	qdisc_list;
 	struct netdev_queue	*next_sched;
-};
+} ____cacheline_aligned_in_smp;
 ...
@@ -641,7 +641,9 @@ struct net_device
 	unsigned char		broadcast[MAX_ADDR_LEN];	/* hw bcast add	*/
 
 	struct netdev_queue	rx_queue;
-	struct netdev_queue	tx_queue ____cacheline_aligned_in_smp;
+
+	struct netdev_queue	*_tx ____cacheline_aligned_in_smp;
+	unsigned int		num_tx_queues;
 	unsigned long		tx_queue_len;	/* Max frames per queue allowed */
 ...

Re: [PATCH 1/13]: netdev: Allocate multiple queues for TX.

[Jarek Poplawski]

On 10-07-2008 12:56, David Miller wrote:
...
> diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
> index 243de93..4e2b865 100644
> --- a/net/sched/sch_generic.c
> +++ b/net/sched/sch_generic.c
> @@ -40,20 +40,30 @@
>   */
>  
>  void qdisc_lock_tree(struct net_device *dev)
> -	__acquires(dev->tx_queue.lock)
>  	__acquires(dev->rx_queue.lock)
>  {
> -	spin_lock_bh(&dev->tx_queue.lock);
> +	unsigned int i;
> +
> +	local_bh_disable();
> +	for (i = 0; i < dev->num_tx_queues; i++) {
> +		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
> +		spin_lock(&txq->lock);

I wonder if it was tested with lockdep? It seems additional
annotation is needed for such nesting (not counting rx_queue.lock
annotation).

Jarek P.

> +	}
>  	spin_lock(&dev->rx_queue.lock);
>  }
>  EXPORT_SYMBOL(qdisc_lock_tree);

Re: [PATCH 1/13]: netdev: Allocate multiple queues for TX.

[David Miller]

From: Jarek Poplawski <jarkao2@gmail.com>
Date: Wed, 16 Jul 2008 07:01:08 +0000

> I wonder if it was tested with lockdep? It seems additional
> annotation is needed for such nesting (not counting rx_queue.lock
> annotation).

I know, and I know about your patch wrt the queue lock
initializations.

I hope to solve that and other things as I respin the multiqueue
changes.

Re: [PATCH 1/13]: netdev: Allocate multiple queues for TX.

[Jarek Poplawski]

On Wed, Jul 16, 2008 at 12:37:00AM -0700, David Miller wrote:
> From: Jarek Poplawski <jarkao2@gmail.com>
> Date: Wed, 16 Jul 2008 07:01:08 +0000
> 
> > I wonder if it was tested with lockdep? It seems additional
> > annotation is needed for such nesting (not counting rx_queue.lock
> > annotation).
> 
> I know, and I know about your patch wrt the queue lock
> initializations.

Fine... I don't think much about this particular patch. I try to read
this code, and... it's hard to guess what do you know, and plan to fix
yet. So it looks like it's better to wait for some official "finished"
sign...

Jarek P.