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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-10-24 06:13:17 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-10-24 06:13:17 -0700 |
| commit | 7c28bd0b8ec4d128bd7660671d1b626b0abc471f (patch) | |
| tree | dbde8ba53e2059dbd6cb19aca18133b33112ddf5 /net/core/dev.c | |
| parent | 8d5b2c084d2e71587e30a6ef528a8a8051e59dcd (diff) | |
| download | lwn-7c28bd0b8ec4d128bd7660671d1b626b0abc471f.tar.gz lwn-7c28bd0b8ec4d128bd7660671d1b626b0abc471f.zip | |
rtnetlink: speedup rtnl_dump_ifinfo()
When handling large number of netdevice, rtnl_dump_ifinfo()
is very slow because it has O(N^2) complexity.
Instead of scanning one single list, we can use the 256 sub lists
of the dev_index hash table.
This considerably speedups "ip link" operations
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 | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index fa88dcd476d6..e7bada1d5ed9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -193,18 +193,15 @@ static struct list_head ptype_all __read_mostly; /* Taps */ DEFINE_RWLOCK(dev_base_lock); EXPORT_SYMBOL(dev_base_lock); -#define NETDEV_HASHBITS 8 -#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) - 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 & ((1 << NETDEV_HASHBITS) - 1)]; + return &net->dev_name_head[hash & (NETDEV_HASHENTRIES - 1)]; } static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex) { - return &net->dev_index_head[ifindex & ((1 << NETDEV_HASHBITS) - 1)]; + return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)]; } /* Device list insertion */ |