[PATCH 2/2] nfnetlink_queue: provide rcu enabled callbacks
From: Eric Dumazet <hidden>
Date: 2011-07-01 15:29:02
nenetlink_queue operations on SMP are not efficent if several queues are used, because of nfnl_mutex contention when applications give packet verdict. Use new call_rcu field in struct nfnl_callback to advertize a callback that is called under rcu_read_lock instead of nfnl_mutex. On my 2x4x2 machine, I was able to reach 2.000.000 pps going through user land returning NF_ACCEPT verdicts without losses, instead of less than 500.000 pps before patch. Signed-off-by: Eric Dumazet <redacted> CC: Florian Westphal <fw@strlen.de> CC: Eric Leblond <redacted> CC: Patrick McHardy <redacted> --- net/netfilter/nfnetlink_queue.c | 41 ++++++++---------------------- 1 files changed, 12 insertions(+), 29 deletions(-)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index fdd2faf..d3692fc 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c@@ -620,39 +620,26 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, struct nfqnl_instance *queue; unsigned int verdict; struct nf_queue_entry *entry; - int err; - rcu_read_lock(); queue = instance_lookup(queue_num); - if (!queue) { - err = -ENODEV; - goto err_out_unlock; - } + if (!queue) + return -ENODEV; - if (queue->peer_pid != NETLINK_CB(skb).pid) { - err = -EPERM; - goto err_out_unlock; - } + if (queue->peer_pid != NETLINK_CB(skb).pid) + return -EPERM; - if (!nfqa[NFQA_VERDICT_HDR]) { - err = -EINVAL; - goto err_out_unlock; - } + if (!nfqa[NFQA_VERDICT_HDR]) + return -EINVAL; vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]); verdict = ntohl(vhdr->verdict); - if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) { - err = -EINVAL; - goto err_out_unlock; - } + if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) + return -EINVAL; entry = find_dequeue_entry(queue, ntohl(vhdr->id)); - if (entry == NULL) { - err = -ENOENT; - goto err_out_unlock; - } - rcu_read_unlock(); + if (entry == NULL) + return -ENOENT; if (nfqa[NFQA_PAYLOAD]) { if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
@@ -665,10 +652,6 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, nf_reinject(entry, verdict); return 0; - -err_out_unlock: - rcu_read_unlock(); - return err; } static int
@@ -781,9 +764,9 @@ err_out_unlock: } static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { - [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, + [NFQNL_MSG_PACKET] = { .call_rcu = nfqnl_recv_unsupp, .attr_count = NFQA_MAX, }, - [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, + [NFQNL_MSG_VERDICT] = { .call_rcu = nfqnl_recv_verdict, .attr_count = NFQA_MAX, .policy = nfqa_verdict_policy }, [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config,