From 91dd93f956b9ea9ecf47fd4b9acd2d2e7f980303 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 12 May 2015 17:24:50 -0700 Subject: [PATCH] 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 --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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; EXPORT_SYMBOL_GPL(nl_table); static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); -- 2.39.5