[NET]: Reorder fields of struct dst_entry

This last patch (but not least :) ) finally moves the next pointer at
the end of struct dst_entry. This permits to perform route cache
lookups with a minimal cost of one cache line per entry, instead of
two.

Both 32bits and 64bits platforms benefit from this new layout.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 10 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 5d62342e8bc4..e12a8ce0b9b3 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -37,14 +37,7 @@ struct sk_buff;
 
 struct dst_entry
 {
-        union {
-                struct dst_entry *next;
-                struct rtable    *rt_next;
-                struct rt6_info   *rt6_next;
-                struct dn_route  *dn_next;
-        };
-        atomic_t                __refcnt;       /* client references    */
-        int                     __use;
+        struct rcu_head         rcu_head;
         struct dst_entry        *child;
         struct net_device       *dev;
         short                   error;
@@ -55,7 +48,6 @@ struct dst_entry
 #define DST_NOPOLICY            4
 #define DST_NOHASH              8
 #define DST_BALANCED            0x10
-        unsigned long           lastuse;
         unsigned long           expires;
 
         unsigned short          header_len;     /* more space at head required */
@@ -80,8 +72,16 @@ struct dst_entry
 #endif
 
         struct  dst_ops         *ops;
-        struct rcu_head         rcu_head;
                 
+        unsigned long           lastuse;
+        atomic_t                __refcnt;       /* client references    */
+        int                     __use;
+        union {
+                struct dst_entry *next;
+                struct rtable    *rt_next;
+                struct rt6_info   *rt6_next;
+                struct dn_route  *dn_next;
+        };
         char                    info[0];
 };