4.19-stable review patch. If anyone has any objections, please let me know.
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From: Li RongQing lirongqing@baidu.com
[ Upstream commit 45cf7959c30402d7c4ea43568a6f1bab0ba6ca63 ]
netperf udp stream shows that eth_type_trans takes certain cpu, so adjust the mac address check order, and firstly check if it is device address, and only check if it is multicast address only if not the device address.
After this change: To unicast, and skb dst mac is device mac, this is most of time reduce a comparision To unicast, and skb dst mac is not device mac, nothing change To multicast, increase a comparision
Before: 1.03% [kernel] [k] eth_type_trans
After: 0.78% [kernel] [k] eth_type_trans
Signed-off-by: Zhang Yu zhangyu31@baidu.com Signed-off-by: Li RongQing lirongqing@baidu.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 6e159fd653d7 ("ethernet: Add helper for assigning packet type when dest address does not match device address") Signed-off-by: Sasha Levin sashal@kernel.org --- net/ethernet/eth.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index ca06e9a53d15c..88a074dd983e6 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c @@ -165,15 +165,17 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) eth = (struct ethhdr *)skb->data; skb_pull_inline(skb, ETH_HLEN);
- if (unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) { - if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast)) - skb->pkt_type = PACKET_BROADCAST; - else - skb->pkt_type = PACKET_MULTICAST; + if (unlikely(!ether_addr_equal_64bits(eth->h_dest, + dev->dev_addr))) { + if (unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) { + if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast)) + skb->pkt_type = PACKET_BROADCAST; + else + skb->pkt_type = PACKET_MULTICAST; + } else { + skb->pkt_type = PACKET_OTHERHOST; + } } - else if (unlikely(!ether_addr_equal_64bits(eth->h_dest, - dev->dev_addr))) - skb->pkt_type = PACKET_OTHERHOST;
/* * Some variants of DSA tagging don't have an ethertype field