[NETFILTER]: nf_conntrack: optimize hash_conntrack()
Avoid calling jhash three times and hash the entire tuple in one go.
__hash_conntrack | -485 # 760 -> 275, # inlines: 3 -> 1, size inlines: 717 -> 252
1 function changed, 485 bytes removed
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index ce4c4ba..4a2cce1 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -73,15 +73,19 @@
static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
unsigned int size, unsigned int rnd)
{
- unsigned int a, b;
+ unsigned int n;
+ u_int32_t h;
- a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all),
- (tuple->src.l3num << 16) | tuple->dst.protonum);
- b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
- ((__force __u16)tuple->src.u.all << 16) |
- (__force __u16)tuple->dst.u.all);
+ /* The direction must be ignored, so we hash everything up to the
+ * destination ports (which is a multiple of 4) and treat the last
+ * three bytes manually.
+ */
+ n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
+ h = jhash2((u32 *)tuple, n,
+ rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
+ tuple->dst.protonum));
- return ((u64)jhash_2words(a, b, rnd) * size) >> 32;
+ return ((u64)h * size) >> 32;
}
static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)