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/decnet/af_decnet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/decnet') diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c index d402e9020c68..65e3baed0251 100644 --- a/net/decnet/af_decnet.c +++ b/net/decnet/af_decnet.c @@ -149,7 +149,7 @@ static void dn_keepalive(struct sock *sk); #define DN_SK_HASH_MASK (DN_SK_HASH_SIZE - 1) -static struct proto_ops dn_proto_ops; +static const struct proto_ops dn_proto_ops; static DEFINE_RWLOCK(dn_hash_lock); static struct hlist_head dn_sk_hash[DN_SK_HASH_SIZE]; static struct hlist_head dn_wild_sk; @@ -2342,7 +2342,7 @@ static struct net_proto_family dn_family_ops = { .owner = THIS_MODULE, }; -static struct proto_ops dn_proto_ops = { +static const struct proto_ops dn_proto_ops = { .family = AF_DECnet, .owner = THIS_MODULE, .release = dn_release, -- cgit v1.2.3-59-g8ed1b