[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 <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index c6a5191..d68eba4 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -758,7 +758,7 @@
struct svc_serv *serv = svsk->sk_server;
struct socket *sock = svsk->sk_sock;
struct socket *newsock;
- struct proto_ops *ops;
+ const struct proto_ops *ops;
struct svc_sock *newsvsk;
int err, slen;