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/x25/af_x25.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/x25') diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 020d73c..ca8b3b0 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -64,7 +64,7 @@ int sysctl_x25_ack_holdback_timeout = X25_DEFAULT_T2; HLIST_HEAD(x25_list); DEFINE_RWLOCK(x25_list_lock); -static struct proto_ops x25_proto_ops; +static const struct proto_ops x25_proto_ops; static struct x25_address null_x25_address = {" "}; @@ -1391,7 +1391,7 @@ static struct net_proto_family x25_family_ops = { .owner = THIS_MODULE, }; -static struct proto_ops SOCKOPS_WRAPPED(x25_proto_ops) = { +static const struct proto_ops SOCKOPS_WRAPPED(x25_proto_ops) = { .family = AF_X25, .owner = THIS_MODULE, .release = x25_release, -- cgit v1.1