[PATCH net-next] fib_rules: reorder struct fib_rules fields

[PATCH net-next] fib_rules: reorder struct fib_rules fields

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

Move refcnt, pref, suppress_ifgroup, suppress_prefixlen out of first
cache line, as they are not used in fast path.

Make sure ctarget & fr_net are in first cache line.

(Assuming 64 bit arches and 64 bytes cache lines)

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/fib_rules.h |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 9d0fcbaa..4b2b557 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -10,23 +10,25 @@
 
 struct fib_rule {
 	struct list_head	list;
-	atomic_t		refcnt;
 	int			iifindex;
 	int			oifindex;
 	u32			mark;
 	u32			mark_mask;
-	u32			pref;
 	u32			flags;
 	u32			table;
-	int			suppress_ifgroup;
-	int			suppress_prefixlen;
 	u8			action;
+	/* 3 bytes hole, try to use */
 	u32			target;
 	struct fib_rule __rcu	*ctarget;
+	struct net		*fr_net;
+
+	atomic_t		refcnt;
+	u32			pref;
+	int			suppress_ifgroup;
+	int			suppress_prefixlen;
 	char			iifname[IFNAMSIZ];
 	char			oifname[IFNAMSIZ];
 	struct rcu_head		rcu;
-	struct net *		fr_net;
 };
 
 struct fib_lookup_arg {

Re: [PATCH net-next] fib_rules: reorder struct fib_rules fields

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sat, 03 Aug 2013 11:50:35 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> Move refcnt, pref, suppress_ifgroup, suppress_prefixlen out of first
> cache line, as they are not used in fast path.
> 
> Make sure ctarget & fr_net are in first cache line.
> 
> (Assuming 64 bit arches and 64 bytes cache lines)
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.