netfilter: nf_queue: place volatile data in own cacheline

As the comment indicates, the data at the end of nfqnl_instance struct is
written on every queue/dequeue, so it should reside in its own cacheline.

Before this change, 'lock' was in first cacheline so we dirtied both.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index af832c5260485f3f99a3dae8fdf0019f896350ef..5379f788a3721486a0406b54e093cbed4a7d1d89 100644 (file)
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -69,7 +69,7 @@ struct nfqnl_instance {
  * Following fields are dirtied for each queued packet,
  * keep them in same cache line if possible.
  */
-       spinlock_t      lock;
+       spinlock_t      lock    ____cacheline_aligned_in_smp;
        unsigned int    queue_total;
        unsigned int    id_sequence;            /* 'sequence' of pkt ids */
        struct list_head queue_list;            /* packets in queue */