From 08e9897d512fe7a67e46209543b3815b57a36dc7 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Tue, 10 Nov 2009 07:20:34 +0000 Subject: [PATCH] netdev: fold name hash properly (v3) The full_name_hash function does not produce well distributed values in the lower bits, so most code uses hash_32() to fold it. This is really a bug introduced when name hashing was added, back in 2.5 when I added name hashing. hash_32 is all that is needed since full_name_hash returns unsigned int which is only 32 bits on 64 bit platforms. Also, there is no point in using hash_32 on ifindex, because the is naturally sequential and usually well distributed. Signed-off-by: Stephen Hemminger Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index bf629ac08b87..ad8e320ceba7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -79,6 +79,7 @@ #include #include #include +#include #include #include #include @@ -196,7 +197,7 @@ EXPORT_SYMBOL(dev_base_lock); static inline struct hlist_head *dev_name_hash(struct net *net, const char *name) { unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ)); - return &net->dev_name_head[hash & (NETDEV_HASHENTRIES - 1)]; + return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)]; } static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex) -- 2.34.1