From 45cf7959c30402d7c4ea43568a6f1bab0ba6ca63 Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Tue, 13 Nov 2018 09:34:31 +0800 Subject: [PATCH] net: slightly optimize eth_type_trans 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 Signed-off-by: Li RongQing Signed-off-by: David S. Miller --- 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 fd8faa0dfa61..58933fa50bb5 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 -- 2.30.2