From: Eric Dumazet <edumazet@google.com>
Date: Fri, 20 Feb 2015 14:48:57 +0000 (-0800)
Subject: rhashtable: ensure cache line alignment on bucket_table
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=b9ebafbe8cfeeddec881504c446cccd0d87a51b6;p=deliverable%2Flinux.git

rhashtable: ensure cache line alignment on bucket_table

struct bucket_table contains mostly read fields :

size, locks_mask, locks.

Make sure these are not sharing a cache line with buckets[]

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 58851275fed9..cb2104be2135 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -54,10 +54,11 @@ struct rhash_head {
  * @buckets: size * hash buckets
  */
 struct bucket_table {
-	size_t				size;
-	unsigned int			locks_mask;
-	spinlock_t			*locks;
-	struct rhash_head __rcu		*buckets[];
+	size_t			size;
+	unsigned int		locks_mask;
+	spinlock_t		*locks;
+
+	struct rhash_head __rcu	*buckets[] ____cacheline_aligned_in_smp;
 };
 
 typedef u32 (*rht_hashfn_t)(const void *data, u32 len, u32 seed);