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| author | Stephen Hemminger <shemminger@vyatta.com> | 2008-04-10 04:00:28 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-04-10 04:00:28 -0700 |
| commit | c0b8c32b1c96afc9b32b717927330025cc1c501e (patch) | |
| tree | 34997f5e86aa375746ecbe4f2c8899b4fa774a5e | |
| parent | 996b1dbadcbcafb899f022303e01d46ab87920eb (diff) | |
| download | op-kernel-dev-c0b8c32b1c96afc9b32b717927330025cc1c501e.zip op-kernel-dev-c0b8c32b1c96afc9b32b717927330025cc1c501e.tar.gz | |
IPV4: use xor rather than multiple ands for route compare
The comparison in ip_route_input is a hot path, by recoding the C
"and" as bit operations, fewer conditional branches get generated
so the code should be faster. Maybe someday Gcc will be smart
enough to do this?
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/route.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a1c5b8d..139799f 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2077,12 +2077,12 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, rcu_read_lock(); for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; rth = rcu_dereference(rth->u.dst.rt_next)) { - if (rth->fl.fl4_dst == daddr && - rth->fl.fl4_src == saddr && - rth->fl.iif == iif && - rth->fl.oif == 0 && + if (((rth->fl.fl4_dst ^ daddr) | + (rth->fl.fl4_src ^ saddr) | + (rth->fl.iif ^ iif) | + rth->fl.oif | + (rth->fl.fl4_tos ^ tos)) == 0 && rth->fl.mark == skb->mark && - rth->fl.fl4_tos == tos && net_eq(dev_net(rth->u.dst.dev), net) && rth->rt_genid == atomic_read(&rt_genid)) { dst_use(&rth->u.dst, jiffies); |
