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>
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 55590ab..815b2ce 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -96,16 +96,16 @@
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;
