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/ax25/af_ax25.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ax25') diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 1b683f302657..8b5d10aaba05 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -54,7 +54,7 @@ HLIST_HEAD(ax25_list); DEFINE_SPINLOCK(ax25_list_lock); -static struct proto_ops ax25_proto_ops; +static const struct proto_ops ax25_proto_ops; static void ax25_free_sock(struct sock *sk) { @@ -1944,7 +1944,7 @@ static struct net_proto_family ax25_family_ops = { .owner = THIS_MODULE, }; -static struct proto_ops ax25_proto_ops = { +static const struct proto_ops ax25_proto_ops = { .family = PF_AX25, .owner = THIS_MODULE, .release = ax25_release, -- cgit v1.2.3-59-g8ed1b