Commit e37ef961 authored Oct 11, 2010 by Eric Dumazet Committed by David S. Miller Oct 11, 2010

neigh: reorder struct neighbour fields



Le mardi 12 octobre 2010 à 00:02 +0200, Eric Dumazet a écrit :
> Here is the followup patch.
>
> Thanks !
>

Oops, this was an old version, the up2date ones also took care of "used"
field.

I guess its time for a sleep, sorry again.

[PATCH net-next V2] neigh: reorder struct neighbour fields

(refcnt) and (ha_lock, ha, used, dev, output, ops, primary_key) should
be placed on a separate cache lines.

refcnt can be often written, while other fields are mostly read.

This gave me good result on stress test :

before:

real    0m45.570s
user    0m15.525s
sys     9m56.669s

After:

real    0m41.841s
user    0m15.261s
sys     8m45.949s

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

parent fc66f95c

include/net/neighbour.h

+4 −4

Original line number	Diff line number	Diff line
		@@ -94,8 +94,6 @@ struct neighbour {
		struct neighbour __rcu *next;
		struct neigh_table *tbl;
		struct neigh_parms *parms;
		struct net_device *dev;
		unsigned long used;
		unsigned long confirmed;
		unsigned long updated;
		__u8 flags;
		@@ -103,16 +101,18 @@ struct neighbour {
		__u8 type;
		__u8 dead;
		atomic_t refcnt;
		struct sk_buff_head arp_queue;
		struct timer_list timer;
		unsigned long used;
		atomic_t probes;
		rwlock_t lock;
		seqlock_t ha_lock;
		unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
		struct hh_cache *hh;
		int (output)(struct sk_buff skb);
		struct sk_buff_head arp_queue;
		struct timer_list timer;
		const struct neigh_ops *ops;
		struct rcu_head rcu;
		struct net_device *dev;
		u8 primary_key[0];
		};

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