diff options
author | Eric Dumazet <edumazet@google.com> | 2014-10-05 18:38:35 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2014-10-07 13:22:11 -0400 |
commit | 0287587884b15041203b3a362d485e1ab1f24445 (patch) | |
tree | 675ae57663c1ba3ee8768e65e7fb0e6d0259e04c /net/8021q | |
parent | fe971b95c22578456ff7198537827841c726d3f7 (diff) | |
download | linux-0287587884b15041203b3a362d485e1ab1f24445.tar.gz |
net: better IFF_XMIT_DST_RELEASE support
Testing xmit_more support with netperf and connected UDP sockets, I found strange dst refcount false sharing. Current handling of IFF_XMIT_DST_RELEASE is not optimal. Dropping dst in validate_xmit_skb() is certainly too late in case packet was queued by cpu X but dequeued by cpu Y The logical point to take care of drop/force is in __dev_queue_xmit() before even taking qdisc lock. As Julian Anastasov pointed out, need for skb_dst() might come from some packet schedulers or classifiers. This patch adds new helper to cleanly express needs of various drivers or qdiscs/classifiers. Drivers that need skb_dst() in their ndo_start_xmit() should call following helper in their setup instead of the prior : dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; -> netif_keep_dst(dev); Instead of using a single bit, we use two bits, one being eventually rebuilt in bonding/team drivers. The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being rebuilt in bonding/team. Eventually, we could add something smarter later. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/8021q')
-rw-r--r-- | net/8021q/vlan_dev.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 35a6b6b15e8a..0d441ec8763e 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -799,7 +799,8 @@ void vlan_setup(struct net_device *dev) ether_setup(dev); dev->priv_flags |= IFF_802_1Q_VLAN; - dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING); + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + netif_keep_dst(dev); dev->tx_queue_len = 0; dev->netdev_ops = &vlan_netdev_ops; |