diff options
| author | stephen hemminger <shemminger@vyatta.com> | 2009-11-10 07:20:34 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-11-11 19:22:12 -0800 |
| commit | 08e9897d512fe7a67e46209543b3815b57a36dc7 (patch) | |
| tree | 0fad8d5d896a0b191f2df1425afa9565041dedae /net/core/dev.c | |
| parent | 7e5ca6a22de8fa79897daae51d76b473e44f8066 (diff) | |
| download | lwn-08e9897d512fe7a67e46209543b3815b57a36dc7.tar.gz lwn-08e9897d512fe7a67e46209543b3815b57a36dc7.zip | |
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 <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 3 |
1 files changed, 2 insertions, 1 deletions
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 <linux/cpu.h> #include <linux/types.h> #include <linux/kernel.h> +#include <linux/hash.h> #include <linux/sched.h> #include <linux/mutex.h> #include <linux/string.h> @@ -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) |