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/unix/af_unix.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/unix') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 04e850e04e3d..7d3fe6aebcdb 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -473,7 +473,7 @@ static int unix_dgram_connect(struct socket *, struct sockaddr *, static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, struct msghdr *, size_t); -static struct proto_ops unix_stream_ops = { +static const struct proto_ops unix_stream_ops = { .family = PF_UNIX, .owner = THIS_MODULE, .release = unix_release, @@ -494,7 +494,7 @@ static struct proto_ops unix_stream_ops = { .sendpage = sock_no_sendpage, }; -static struct proto_ops unix_dgram_ops = { +static const struct proto_ops unix_dgram_ops = { .family = PF_UNIX, .owner = THIS_MODULE, .release = unix_release, @@ -515,7 +515,7 @@ static struct proto_ops unix_dgram_ops = { .sendpage = sock_no_sendpage, }; -static struct proto_ops unix_seqpacket_ops = { +static const struct proto_ops unix_seqpacket_ops = { .family = PF_UNIX, .owner = THIS_MODULE, .release = unix_release, -- cgit v1.2.3