path: root/net
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authorEric Dumazet <>2015-05-12 17:24:50 -0700
committerDavid S. Miller <>2015-05-14 17:49:06 -0400
commit91dd93f956b9ea9ecf47fd4b9acd2d2e7f980303 (patch)
tree1144107d6ac2f98703f314450ebb866baf6bcbad /net
parentbe346ffaad9bc354075fba5cd009fc4519abdd64 (diff)
netlink: move nl_table in read_mostly section
netlink sockets creation and deletion heavily modify nl_table_users and nl_table_lock. If nl_table is sharing one cache line with one of them, netlink performance is really bad on SMP. ffffffff81ff5f00 B nl_table ffffffff81ff5f0c b nl_table_users Putting nl_table in read_mostly section increased performance of my open/delete netlink sockets test by about 80 % This came up while diagnosing a getaddrinfo() problem. Signed-off-by: Eric Dumazet <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index daa0b818174b..dbe885901b34 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -89,7 +89,7 @@ static inline int netlink_is_kernel(struct sock *sk)
return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
-struct netlink_table *nl_table;
+struct netlink_table *nl_table __read_mostly;
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);