IPV4: route use jhash3

Since route hash is a triple, use jhash_3words rather doing the mixing
directly. This should be as fast and give better distribution.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index d758ea1d80f6..7cdd2bf88e0c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -259,16 +259,14 @@ static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
 #define RT_CACHE_STAT_INC(field) \
         (__raw_get_cpu_var(rt_cache_stat).field++)
 
-static unsigned int rt_hash_code(u32 daddr, u32 saddr)
+static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx)
 {
-        return jhash_2words(daddr, saddr, atomic_read(&rt_genid))
+        return jhash_3words((__force u32)(__be32)(daddr),
+                            (__force u32)(__be32)(saddr),
+                            idx, atomic_read(&rt_genid))
                 & rt_hash_mask;
 }
 
-#define rt_hash(daddr, saddr, idx) \
-        rt_hash_code((__force u32)(__be32)(daddr),\
-                     (__force u32)(__be32)(saddr) ^ ((idx) << 5))
-
 #ifdef CONFIG_PROC_FS
 struct rt_cache_iter_state {
         struct seq_net_private p;