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authorEric Dumazet <eric.dumazet@gmail.com>2009-10-24 06:13:17 -0700
committerDavid S. Miller <davem@davemloft.net>2009-10-24 06:13:17 -0700
commit7c28bd0b8ec4d128bd7660671d1b626b0abc471f (patch)
treedbde8ba53e2059dbd6cb19aca18133b33112ddf5 /net/core/dev.c
parent8d5b2c084d2e71587e30a6ef528a8a8051e59dcd (diff)
downloadlwn-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.c7
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 */