[NET]: use __read_mostly on kmem_cache_t , DEFINE_SNMP_STAT pointers

This patch puts mostly read only data in the right section
(read_mostly), to help sharing of these data between CPUS without
memory ping pongs.

On one of my production machine, tcp_statistics was sitting in a
heavily modified cache line, so *every* SNMP update had to force a
reload.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 2 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index fe4cc85f5bcc..cf93b019ecbe 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -85,7 +85,7 @@ static int ccid3_debug;
 static struct dccp_tx_hist *ccid3_tx_hist;
 static struct dccp_rx_hist *ccid3_rx_hist;
 
-static kmem_cache_t *ccid3_loss_interval_hist_slab;
+static kmem_cache_t *ccid3_loss_interval_hist_slab __read_mostly;
 
 static inline struct ccid3_loss_interval_hist_entry *
         ccid3_loss_interval_hist_entry_new(const unsigned int __nocast prio)
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 600dda51d995..f97e92ea34f3 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -39,7 +39,7 @@
 #include "ccid.h"
 #include "dccp.h"
 
-DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics);
+DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
 
 atomic_t dccp_orphan_count = ATOMIC_INIT(0);