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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Ben Hutchings <ben.hutchings@codethink.co.uk>
Subject: [PATCH 4.4 19/34] inet: frags: reorganize struct netns_frags
Date:   Thu,  7 Feb 2019 12:42:01 +0100
Message-Id: <20190207113026.325520813@linuxfoundation.org>
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4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>

commit c2615cf5a761b32bf74e85bddc223dfff3d9b9f0 upstream.

Put the read-mostly fields in a separate cache line
at the beginning of struct netns_frags, to reduce
false sharing noticed in inet_frag_kill()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/net/inet_frag.h |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -4,15 +4,16 @@
 #include <linux/rhashtable.h>
 
 struct netns_frags {
-	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
-
-	/* Keep atomic mem on separate cachelines in structs that include it */
-	atomic_long_t		mem ____cacheline_aligned_in_smp;
 	/* sysctls */
 	long			high_thresh;
 	long			low_thresh;
 	int			timeout;
 	struct inet_frags	*f;
+
+	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
+
+	/* Keep atomic mem on separate cachelines in structs that include it */
+	atomic_long_t		mem ____cacheline_aligned_in_smp;
 };
 
 /**