From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] netdev: handle setting transmit queue length on active device. Date: Wed, 18 Mar 2009 11:20:38 -0700 Message-ID: <20090318112038.59b689f8@nehalam> References: <20090318100237.06e974c9@nehalam> <49C12C3A.9080107@trash.net> <20090318110236.7fd09d09@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Patrick McHardy , David Miller , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from mail.vyatta.com ([76.74.103.46]:33648 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756368AbZCRSUq (ORCPT ); Wed, 18 Mar 2009 14:20:46 -0400 In-Reply-To: <20090318110236.7fd09d09@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: Some virtual devices like VLAN's or bridges by default have not transmit queue. In order to do queuing disciplines on these devices a queue must be added by setting transmit queue length. The kernel allows doing this at any time, but setting the queue length value is not enough. Setting the queue length does not create the transmit queue (going from 0 to non-zero) or destroy it (setting to zero); the queue is only created (or destroyed) when device comes up (or goes down). This patch handles this be doing the necessary activations. Signed-off-by: Stephen Hemminger --- include/linux/netdevice.h | 2 ++ net/core/dev.c | 19 +++++++++++++++++-- net/core/net-sysfs.c | 5 ++--- net/core/rtnetlink.c | 2 +- 4 files changed, 22 insertions(+), 6 deletions(-) --- a/include/linux/netdevice.h 2009-03-17 11:06:40.358479573 -0700 +++ b/include/linux/netdevice.h 2009-03-17 11:13:55.243604979 -0700 @@ -1436,6 +1436,8 @@ extern int dev_change_net_namespace(str extern int dev_set_mtu(struct net_device *, int); extern int dev_set_mac_address(struct net_device *, struct sockaddr *); +extern int dev_set_tx_queue_len(struct net_device *dev, + unsigned long len); extern int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq); --- a/net/core/dev.c 2009-03-17 11:05:54.919541341 -0700 +++ b/net/core/dev.c 2009-03-18 11:11:12.678298789 -0700 @@ -983,6 +983,30 @@ int dev_set_alias(struct net_device *dev return len; } +/** + * + * @dev: device + * @len: limit of frames in transmit queue + * + * Set transmit queue length for device. + * If queue length is set to 0, then queueing is disabled. + */ +int dev_set_tx_queue_len(struct net_device *dev, unsigned long len) +{ + if (len == dev->tx_queue_len) + return 0; + + if ((dev->tx_queue_len != 0) && (len != 0)) + dev->tx_queue_len = len; + else { + if (dev->flags & IFF_UP) + dev_deactivate(dev); + dev->tx_queue_len = len; + if (dev->flags & IFF_UP) + dev_activate(dev); + } + return 0; +} /** * netdev_features_change - device changes features @@ -3975,8 +3999,7 @@ static int dev_ifsioc(struct net *net, s case SIOCSIFTXQLEN: if (ifr->ifr_qlen < 0) return -EINVAL; - dev->tx_queue_len = ifr->ifr_qlen; - return 0; + return dev_set_tx_queue_len(dev, ifr->ifr_qlen); case SIOCSIFNAME: ifr->ifr_newname[IFNAMSIZ-1] = '\0'; --- a/net/core/net-sysfs.c 2009-03-17 11:05:54.896453584 -0700 +++ b/net/core/net-sysfs.c 2009-03-17 11:10:10.877230558 -0700 @@ -198,10 +198,9 @@ static ssize_t store_flags(struct device NETDEVICE_SHOW(tx_queue_len, fmt_ulong); -static int change_tx_queue_len(struct net_device *net, unsigned long new_len) +static int change_tx_queue_len(struct net_device *netdev, unsigned long new_len) { - net->tx_queue_len = new_len; - return 0; + return dev_set_tx_queue_len(netdev, new_len); } static ssize_t store_tx_queue_len(struct device *dev, --- a/net/core/rtnetlink.c 2009-03-17 11:10:47.540541648 -0700 +++ b/net/core/rtnetlink.c 2009-03-17 11:11:28.722542409 -0700 @@ -885,7 +885,7 @@ static int do_setlink(struct net_device } if (tb[IFLA_TXQLEN]) - dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]); + dev_set_tx_queue_len(dev, nla_get_u32(tb[IFLA_TXQLEN])); if (tb[IFLA_OPERSTATE]) set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));