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/llc/af_llc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/llc') diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index b6d3df5c911c..9cf65f9d8902 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -36,7 +36,7 @@ static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; static u16 llc_ui_sap_link_no_max[256]; static struct sockaddr_llc llc_ui_addrnull; -static struct proto_ops llc_ui_ops; +static const struct proto_ops llc_ui_ops; static int llc_ui_wait_for_conn(struct sock *sk, long timeout); static int llc_ui_wait_for_disc(struct sock *sk, long timeout); @@ -1098,7 +1098,7 @@ static struct net_proto_family llc_ui_family_ops = { .owner = THIS_MODULE, }; -static struct proto_ops llc_ui_ops = { +static const struct proto_ops llc_ui_ops = { .family = PF_LLC, .owner = THIS_MODULE, .release = llc_ui_release, -- cgit v1.2.3