From c5256c51232d8312755e8de2b514c426b19b101a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 23 Sep 2010 00:46:11 +0000 Subject: [PATCH] net: propagate NETIF_F_HIGHDMA to vlans Automatically allows vlans to get NETIF_F_HIGHDMA if underlying device supports it. On 32bit arches (and more precisely if CONFIG_HIGHMEM is enabled), it can help to reduce cost of illegal_highdma() and __skb_linearize() calls. Tested on tg3 , bnx2, bonding, this worked very well. This is a generalization of a patch provided by Yi Zou & Jeff Kirsher. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 2c7934f8cf3e..e0c0b86f57a1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5058,10 +5058,11 @@ int register_netdevice(struct net_device *dev) if (dev->features & NETIF_F_SG) dev->features |= NETIF_F_GSO; - /* Enable GRO for vlans by default if dev->features has GRO also. - * vlan_dev_init() will do the dev->features check. + /* Enable GRO and NETIF_F_HIGHDMA for vlans by default, + * vlan_dev_init() will do the dev->features check, so these features + * are enabled only if supported by underlying device. */ - dev->vlan_features |= NETIF_F_GRO; + dev->vlan_features |= (NETIF_F_GRO | NETIF_F_HIGHDMA); ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev); ret = notifier_to_errno(ret); -- 2.20.1