Commit 08294a26 authored by Jason Wang's avatar Jason Wang Committed by David S. Miller
Browse files

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: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bf900b3d

include/linux/netdevice.h

+1 −0
Original line number Diff line number Diff line
@@ -2237,6 +2237,7 @@ struct netdev_lag_lower_state_info { 
#define NETDEV_PRECHANGEUPPER	0x001A

#define NETDEV_CHANGELOWERSTATE	0x001B

#define NETDEV_UDP_TUNNEL_PUSH_INFO	0x001C

#define NETDEV_CHANGE_TX_QUEUE_LEN	0x001E



int register_netdevice_notifier(struct notifier_block *nb);

int unregister_netdevice_notifier(struct notifier_block *nb);

net/core/net-sysfs.c

+14 −1
Original line number Diff line number Diff line
@@ -322,7 +322,20 @@ NETDEVICE_SHOW_RW(flags, fmt_hex); 


static int change_tx_queue_len(struct net_device *dev, unsigned long 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;

}

net/core/rtnetlink.c

+12 −4
Original line number Diff line number Diff line
@@ -1927,11 +1927,19 @@ static int do_setlink(const struct sk_buff *skb, 


	if (tb[IFLA_TXQLEN]) {

		unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]);

		unsigned long orig_len = dev->tx_queue_len;



		if (dev->tx_queue_len ^ value)

			status |= DO_SETLINK_NOTIFY;



		if (dev->tx_queue_len ^ value) {

			dev->tx_queue_len = value;

			err = call_netdevice_notifiers(

			      NETDEV_CHANGE_TX_QUEUE_LEN, dev);

			err = notifier_to_errno(err);

			if (err) {

				dev->tx_queue_len = orig_len;

				goto errout;

			}

			status |= DO_SETLINK_NOTIFY;

		}

	}



	if (tb[IFLA_OPERSTATE])

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