Re: [net-next v10 1/2] net: sched: use queue_mapping to pick tx queue

  include/linux/netdevice.h |  3 +++
  include/linux/rtnetlink.h |  1 +
  net/core/dev.c            | 31 +++++++++++++++++++++++++++++--
  net/sched/act_skbedit.c   |  6 +++++-
  4 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0d994710b335..f33fb2d6712a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h

@@ -3065,6 +3065,9 @@ struct softnet_data {
  	struct {
  		u16 recursion;
  		u8  more;
+#ifdef CONFIG_NET_EGRESS
+		u8  skip_txqueue;
+#endif
  	} xmit;
  #ifdef CONFIG_RPS
  	/* input_queue_head should be written by cpu owning this struct,

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 7f970b16da3a..ae2c6a3cec5d 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h

@@ -100,6 +100,7 @@ void net_dec_ingress_queue(void);
  #ifdef CONFIG_NET_EGRESS
  void net_inc_egress_queue(void);
  void net_dec_egress_queue(void);
+void netdev_xmit_skip_txqueue(bool skip);
  #endif
  
  void rtnetlink_init(void);

diff --git a/net/core/dev.c b/net/core/dev.c
index 75bab5b0dbae..8e83b7099977 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c

@@ -3908,6 +3908,25 @@ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
  
  	return skb;
  }
+
+static struct netdev_queue *
+netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
+{
+	int qm = skb_get_queue_mapping(skb);
+
+	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
+}
+
+static bool netdev_xmit_txqueue_skipped(void)
+{
+	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
+}
+
+void netdev_xmit_skip_txqueue(bool skip)
+{
+	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
+}
+EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
  #endif /* CONFIG_NET_EGRESS */
  
  #ifdef CONFIG_XPS

@@ -4078,7 +4097,7 @@ struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
  static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
  {
  	struct net_device *dev = skb->dev;
-	struct netdev_queue *txq;
+	struct netdev_queue *txq = NULL;
  	struct Qdisc *q;
  	int rc = -ENOMEM;
  	bool again = false;

@@ -4106,11 +4125,17 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
  			if (!skb)
  				goto out;
  		}
+
+		netdev_xmit_skip_txqueue(false);
+
  		nf_skip_egress(skb, true);
  		skb = sch_handle_egress(skb, &rc, dev);
  		if (!skb)
  			goto out;
  		nf_skip_egress(skb, false);
+
+		if (netdev_xmit_txqueue_skipped())
+			txq = netdev_tx_queue_mapping(dev, skb);
  	}
  #endif
  	/* If device/qdisc don't need skb->dst, release it right now while

@@ -4121,7 +4146,9 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
  	else
  		skb_dst_force(skb);
  
-	txq = netdev_core_pick_tx(dev, skb, sb_dev);
+	if (likely(!txq))

+		txq = netdev_core_pick_tx(dev, skb, sb_dev);
+
  	q = rcu_dereference_bh(txq->qdisc);

  	trace_net_dev_queue(skb);

diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index ceba11b198bb..d5799b4fc499 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c

@@ -58,8 +58,12 @@ static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a,
  		}
  	}
  	if (params->flags & SKBEDIT_F_QUEUE_MAPPING &&
-	    skb->dev->real_num_tx_queues > params->queue_mapping)
+	    skb->dev->real_num_tx_queues > params->queue_mapping) {
+#ifdef CONFIG_NET_EGRESS
+		netdev_xmit_skip_txqueue(true);
+#endif
  		skb_set_queue_mapping(skb, params->queue_mapping);
+	}
  	if (params->flags & SKBEDIT_F_MARK) {
  		skb->mark &= ~params->mask;
  		skb->mark |= params->mark & params->mask;