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/ipv4/af_inet.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 617e858..4ed8a81 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -785,7 +785,7 @@ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) return err; } -struct proto_ops inet_stream_ops = { +const struct proto_ops inet_stream_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, @@ -806,7 +806,7 @@ struct proto_ops inet_stream_ops = { .sendpage = tcp_sendpage }; -struct proto_ops inet_dgram_ops = { +const struct proto_ops inet_dgram_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, @@ -831,7 +831,7 @@ struct proto_ops inet_dgram_ops = { * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without * udp_poll */ -static struct proto_ops inet_sockraw_ops = { +static const struct proto_ops inet_sockraw_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, -- cgit v1.1