net: decreasing real_num_tx_queues needs to flush qdisc

[linux-drm-fsl-dcu.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 2b3bf53bc687aab3c9cfb32cce902eaebb3c18da..723a34710ad401ff24afd5b1be1af86505f7da33 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1553,6 +1553,24 @@ static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
        rcu_read_unlock();
 }
 
+/*
+ * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
+ * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
+ */
+void netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
+{
+       unsigned int real_num = dev->real_num_tx_queues;
+
+       if (unlikely(txq > dev->num_tx_queues))
+               ;
+       else if (txq > real_num)
+               dev->real_num_tx_queues = txq;
+       else if (txq < real_num) {
+               dev->real_num_tx_queues = txq;
+               qdisc_reset_all_tx_gt(dev, txq);
+       }
+}
+EXPORT_SYMBOL(netif_set_real_num_tx_queues);
 
 static inline void __netif_reschedule(struct Qdisc *q)
 {