From: Eric Dumazet <eric.dumazet@xxxxxxxxx>
- Use an atomic_t for id_sequence to avoid a spin_lock/spin_unlock pair
- Group highly modified struct nfqnl_instance fields together
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
---
net/netfilter/nfnetlink_queue.c | 33 ++++++++++++++-------------------
1 files changed, 14 insertions(+), 19 deletions(-)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 12e1ab3..d05605b 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -46,17 +46,19 @@ struct nfqnl_instance {
int peer_pid;
unsigned int queue_maxlen;
unsigned int copy_range;
- unsigned int queue_total;
unsigned int queue_dropped;
unsigned int queue_user_dropped;
- unsigned int id_sequence; /* 'sequence' of pkt ids */
u_int16_t queue_num; /* number of this queue */
u_int8_t copy_mode;
-
- spinlock_t lock;
-
+/*
+ * Following fields are dirtied for each queued packet,
+ * keep them in same cache line if possible.
+ */
+ spinlock_t lock;
+ unsigned int queue_total;
+ atomic_t id_sequence; /* 'sequence' of pkt ids */
struct list_head queue_list; /* packets in queue */
};
@@ -238,32 +240,24 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
outdev = entry->outdev;
- spin_lock_bh(&queue->lock);
-
- switch ((enum nfqnl_config_mode)queue->copy_mode) {
+ switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
case NFQNL_COPY_META:
case NFQNL_COPY_NONE:
break;
case NFQNL_COPY_PACKET:
if (entskb->ip_summed == CHECKSUM_PARTIAL &&
- skb_checksum_help(entskb)) {
- spin_unlock_bh(&queue->lock);
+ skb_checksum_help(entskb))
return NULL;
- }
- if (queue->copy_range == 0
- || queue->copy_range > entskb->len)
+
+ data_len = ACCESS_ONCE(queue->copy_range);
+ if (data_len == 0 || data_len > entskb->len)
data_len = entskb->len;
- else
- data_len = queue->copy_range;
size += nla_total_size(data_len);
break;
}
- entry->id = queue->id_sequence++;
-
- spin_unlock_bh(&queue->lock);
skb = alloc_skb(size, GFP_ATOMIC);
if (!skb)
@@ -278,6 +272,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = htons(queue->queue_num);
+ entry->id = atomic_inc_return(&queue->id_sequence);
pmsg.packet_id = htonl(entry->id);
pmsg.hw_protocol = entskb->protocol;
pmsg.hook = entry->hook;
@@ -866,7 +861,7 @@ static int seq_show(struct seq_file *s, void *v)
inst->peer_pid, inst->queue_total,
inst->copy_mode, inst->copy_range,
inst->queue_dropped, inst->queue_user_dropped,
- inst->id_sequence, 1);
+ atomic_read(&inst->id_sequence), 1);
}
static const struct seq_operations nfqnl_seq_ops = {
--
1.7.0.4
--
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