[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>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5810f9d..bf147f8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -113,7 +113,7 @@
#include <linux/mroute.h>
#endif
-DEFINE_SNMP_STAT(struct linux_mib, net_statistics);
+DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly;
extern void ip_mc_drop_socket(struct sock *sk);