aboutsummaryrefslogtreecommitdiffstats
path: root/net/ethernet/eth.c
diff options
context:
space:
mode:
authorEric Dumazet <dada1@cosmosbay.com>2008-11-23 23:24:32 -0800
committerDavid S. Miller <davem@davemloft.net>2008-11-23 23:24:32 -0800
commit1f87e235e6fb92c2968b52b9191de04f1aff8e77 (patch)
treeab774d239c61b6c206ef07398828533cdd01915e /net/ethernet/eth.c
parent70eb1bfd52e97120eddf9b5aaabfe1ecdf4eb663 (diff)
eth: Declare an optimized compare_ether_addr_64bits() function
Linus mentioned we could try to perform long word operations, even on potentially unaligned addresses, on x86 at least. David mentioned the HAVE_EFFICIENT_UNALIGNED_ACCESS test to handle this on all arches that have efficient unailgned accesses. I tried this idea and got nice assembly on 32 bits: 158: 33 82 38 01 00 00 xor 0x138(%edx),%eax 15e: 33 8a 34 01 00 00 xor 0x134(%edx),%ecx 164: c1 e0 10 shl $0x10,%eax 167: 09 c1 or %eax,%ecx 169: 74 0b je 176 <eth_type_trans+0x87> And very nice assembly on 64 bits of course (one xor, one shl) Nice oprofile improvement in eth_type_trans(), 0.17 % instead of 0.41 %, expected since we remove 8 instructions on a fast path. This patch implements a compare_ether_addr_64bits() function, that uses the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS ifdef to efficiently perform the 6 bytes comparison on all capable arches. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ethernet/eth.c')
-rw-r--r--net/ethernet/eth.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index a87a171d9914..280352aba403 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -165,8 +165,8 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
skb_pull(skb, ETH_HLEN);
eth = eth_hdr(skb);
- if (is_multicast_ether_addr(eth->h_dest)) {
- if (!compare_ether_addr(eth->h_dest, dev->broadcast))
+ if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
+ if (!compare_ether_addr_64bits(eth->h_dest, dev->broadcast))
skb->pkt_type = PACKET_BROADCAST;
else
skb->pkt_type = PACKET_MULTICAST;
@@ -181,7 +181,7 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
*/
else if (1 /*dev->flags&IFF_PROMISC */ ) {
- if (unlikely(compare_ether_addr(eth->h_dest, dev->dev_addr)))
+ if (unlikely(compare_ether_addr_64bits(eth->h_dest, dev->dev_addr)))
skb->pkt_type = PACKET_OTHERHOST;
}

Privacy Policy