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authorLi RongQing <lirongqing@baidu.com>2018-11-13 04:34:31 +0300
committerDavid S. Miller <davem@davemloft.net>2018-11-16 02:10:59 +0300
commit45cf7959c30402d7c4ea43568a6f1bab0ba6ca63 (patch)
tree0c8672578e4d0a9f5c60ad6310ccb55dc47f668f /net
parent982c17b9e3c27389a8d214333c686dab0e95cf63 (diff)
downloadlinux-45cf7959c30402d7c4ea43568a6f1bab0ba6ca63.tar.xz
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 <zhangyu31@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ethernet/eth.c18
1 files 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