From 90ddc4f0470427df306f308ad03db6b6b21644b8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 22 Dec 2005 12:49:22 -0800 Subject: [NET]: move struct proto_ops to const I noticed that some of 'struct proto_ops' used in the kernel may share a cache line used by locks or other heavily modified data. (default linker alignement is 32 bytes, and L1_CACHE_LINE is 64 or 128 at least) This patch makes sure a 'struct proto_ops' can be declared as const, so that all cpus can share all parts of it without false sharing. This is not mandatory : a driver can still use a read/write structure if it needs to (and eventually a __read_mostly) I made a global stubstitute to change all existing occurences to make them const. This should reduce the possibility of false sharing on SMP, and speedup some socket system calls. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/netlink') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 96020d7087e8..7849cac14d3a 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -293,7 +293,7 @@ static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) return 0; } -static struct proto_ops netlink_ops; +static const struct proto_ops netlink_ops; static int netlink_insert(struct sock *sk, u32 pid) { @@ -1656,7 +1656,7 @@ int netlink_unregister_notifier(struct notifier_block *nb) return notifier_chain_unregister(&netlink_chain, nb); } -static struct proto_ops netlink_ops = { +static const struct proto_ops netlink_ops = { .family = PF_NETLINK, .owner = THIS_MODULE, .release = netlink_release, -- cgit v1.2.3-59-g8ed1b