net: introduce NETDEV_CHANGE_TX_QUEUE_LEN

This patch introduces a new event - NETDEV_CHANGE_TX_QUEUE_LEN, this
will be triggered when tx_queue_len. It could be used by net device
who want to do some processing at that time. An example is tun who may
want to resize tx array when tx_queue_len is changed.

Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang
2016-06-30 14:45:35 +08:00
committed by David S. Miller
parent bf900b3dbe
commit 08294a26e1
3 changed files with 26 additions and 4 deletions

View File

@ -322,7 +322,20 @@ NETDEVICE_SHOW_RW(flags, fmt_hex);
static int change_tx_queue_len(struct net_device *dev, unsigned long new_len)
{
dev->tx_queue_len = new_len;
int res, orig_len = dev->tx_queue_len;
if (new_len != orig_len) {
dev->tx_queue_len = new_len;
res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
res = notifier_to_errno(res);
if (res) {
netdev_err(dev,
"refused to change device tx_queue_len\n");
dev->tx_queue_len = orig_len;
return -EFAULT;
}
}
return 0;
}