[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>

5 files changed, 5 insertions, 5 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index ff685f229b69..5176fc655ea9 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -67,7 +67,7 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
-DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics);
+DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly;
 
 /*
  *      The ICMP socket(s). This is the most convenient way to flow control
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 1b354aa97934..16af874c9e8f 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -49,7 +49,7 @@
 
 struct rt6_statistics   rt6_stats;
 
-static kmem_cache_t * fib6_node_kmem;
+static kmem_cache_t * fib6_node_kmem __read_mostly;
 
 enum fib_walk_state_t
 {
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 7516b8829a9d..76466af8331e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -55,7 +55,7 @@
 
 #include <asm/uaccess.h>
 
-DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics);
+DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics) __read_mostly;
 
 static struct packet_type ipv6_packet_type = {
         .type = __constant_htons(ETH_P_IPV6), 
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 67d9a04b6902..390d750449ce 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -59,7 +59,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
-DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6);
+DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
 
 /* Grrr, addr_type already calculated by caller, but I don't want
  * to add some silly "cookie" argument to this method just for that.
diff --git a/net/ipv6/xfrm6_tunnel.c b/net/ipv6/xfrm6_tunnel.c
index 60c26c87277e..fbef7826a74f 100644
--- a/net/ipv6/xfrm6_tunnel.c
+++ b/net/ipv6/xfrm6_tunnel.c
@@ -79,7 +79,7 @@ static u32 xfrm6_tunnel_spi;
 #define XFRM6_TUNNEL_SPI_MIN    1
 #define XFRM6_TUNNEL_SPI_MAX    0xffffffff
 
-static kmem_cache_t *xfrm6_tunnel_spi_kmem;
+static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly;
 
 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256