[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/ipv6/udp.c b/net/ipv6/udp.c
index 67d9a04..390d750 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.