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/packet/af_packet.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 3e2462760413..deda6fdb1e53 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -251,10 +251,10 @@ static void packet_sock_destruct(struct sock *sk) } -static struct proto_ops packet_ops; +static const struct proto_ops packet_ops; #ifdef CONFIG_SOCK_PACKET -static struct proto_ops packet_ops_spkt; +static const struct proto_ops packet_ops_spkt; static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { @@ -1784,7 +1784,7 @@ out: #ifdef CONFIG_SOCK_PACKET -static struct proto_ops packet_ops_spkt = { +static const struct proto_ops packet_ops_spkt = { .family = PF_PACKET, .owner = THIS_MODULE, .release = packet_release, @@ -1806,7 +1806,7 @@ static struct proto_ops packet_ops_spkt = { }; #endif -static struct proto_ops packet_ops = { +static const struct proto_ops packet_ops = { .family = PF_PACKET, .owner = THIS_MODULE, .release = packet_release, -- cgit v1.2.3