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/irda/af_irda.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'net/irda') diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c index f121f7de2032..e57683d424f7 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -62,12 +62,12 @@ static int irda_create(struct socket *sock, int protocol); -static struct proto_ops irda_stream_ops; -static struct proto_ops irda_seqpacket_ops; -static struct proto_ops irda_dgram_ops; +static const struct proto_ops irda_stream_ops; +static const struct proto_ops irda_seqpacket_ops; +static const struct proto_ops irda_dgram_ops; #ifdef CONFIG_IRDA_ULTRA -static struct proto_ops irda_ultra_ops; +static const struct proto_ops irda_ultra_ops; #define ULTRA_MAX_DATA 382 #endif /* CONFIG_IRDA_ULTRA */ @@ -2464,7 +2464,7 @@ static struct net_proto_family irda_family_ops = { .owner = THIS_MODULE, }; -static struct proto_ops SOCKOPS_WRAPPED(irda_stream_ops) = { +static const struct proto_ops SOCKOPS_WRAPPED(irda_stream_ops) = { .family = PF_IRDA, .owner = THIS_MODULE, .release = irda_release, @@ -2485,7 +2485,7 @@ static struct proto_ops SOCKOPS_WRAPPED(irda_stream_ops) = { .sendpage = sock_no_sendpage, }; -static struct proto_ops SOCKOPS_WRAPPED(irda_seqpacket_ops) = { +static const struct proto_ops SOCKOPS_WRAPPED(irda_seqpacket_ops) = { .family = PF_IRDA, .owner = THIS_MODULE, .release = irda_release, @@ -2506,7 +2506,7 @@ static struct proto_ops SOCKOPS_WRAPPED(irda_seqpacket_ops) = { .sendpage = sock_no_sendpage, }; -static struct proto_ops SOCKOPS_WRAPPED(irda_dgram_ops) = { +static const struct proto_ops SOCKOPS_WRAPPED(irda_dgram_ops) = { .family = PF_IRDA, .owner = THIS_MODULE, .release = irda_release, @@ -2528,7 +2528,7 @@ static struct proto_ops SOCKOPS_WRAPPED(irda_dgram_ops) = { }; #ifdef CONFIG_IRDA_ULTRA -static struct proto_ops SOCKOPS_WRAPPED(irda_ultra_ops) = { +static const struct proto_ops SOCKOPS_WRAPPED(irda_ultra_ops) = { .family = PF_IRDA, .owner = THIS_MODULE, .release = irda_release, -- cgit v1.2.1