neigh: reorder struct neighbour

It is important to move nud_state outside of the often modified cache
line (because of refcnt), to reduce false sharing in neigh_event_send()

This is a followup of commit 0ed8ddf4045f (neigh: Protect neigh->ha[]
with a seqlock)

This gives a 7% speedup on routing test with IP route cache disabled.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 5 deletions

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 55590ab16b3e..815b2ce9f4a4 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -96,16 +96,16 @@ struct neighbour {
         struct neigh_parms      *parms;
         unsigned long           confirmed;
         unsigned long           updated;
-        __u8                    flags;
-        __u8                    nud_state;
-        __u8                    type;
-        __u8                    dead;
+        rwlock_t                lock;
         atomic_t                refcnt;
         struct sk_buff_head     arp_queue;
         struct timer_list       timer;
         unsigned long           used;
         atomic_t                probes;
-        rwlock_t                lock;
+        __u8                    flags;
+        __u8                    nud_state;
+        __u8                    type;
+        __u8                    dead;
         seqlock_t               ha_lock;
         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
         struct hh_cache         *hh;