netfilter: xt_rateest: Better struct xt_rateest layout
We currently dirty two cache lines in struct xt_rateest, this hurts SMP
performance.
This patch moves lock/bstats/rstats at beginning of structure so that
they share a single cache line.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h
index ddbf37e..b1d780e 100644
--- a/include/net/netfilter/xt_rateest.h
+++ b/include/net/netfilter/xt_rateest.h
@@ -2,13 +2,17 @@
#define _XT_RATEEST_H
struct xt_rateest {
+ /* keep lock and bstats on same cache line to speedup xt_rateest_tg() */
+ struct gnet_stats_basic_packed bstats;
+ spinlock_t lock;
+ /* keep rstats and lock on same cache line to speedup xt_rateest_mt() */
+ struct gnet_stats_rate_est rstats;
+
+ /* following fields not accessed in hot path */
struct hlist_node list;
char name[IFNAMSIZ];
unsigned int refcnt;
- spinlock_t lock;
struct gnet_estimator params;
- struct gnet_stats_rate_est rstats;
- struct gnet_stats_basic_packed bstats;
};
extern struct xt_rateest *xt_rateest_lookup(const char *name);