[PATCH] net: fix the flow limitation computation

[roy.qing.li@gmail.com]

From: Li RongQing <roy.qing.li@gmail.com>

Once RPS is enabled, the skb maybe enqueue to different CPU, so the
flow limitation computation should use the enqueued CPU, not the local
CPU

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
---
 net/core/dev.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 945bbd0..e70507d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3250,7 +3250,7 @@ static int rps_ipi_queued(struct softnet_data *sd)
 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
 #endif
 
-static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
+static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen, int cpu)
 {
 #ifdef CONFIG_NET_FLOW_LIMIT
 	struct sd_flow_limit *fl;
@@ -3260,7 +3260,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
 	if (qlen < (netdev_max_backlog >> 1))
 		return false;
 
-	sd = this_cpu_ptr(&softnet_data);
+	sd = &per_cpu(softnet_data, cpu);
 
 	rcu_read_lock();
 	fl = rcu_dereference(sd->flow_limit);
@@ -3303,7 +3303,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
 
 	rps_lock(sd);
 	qlen = skb_queue_len(&sd->input_pkt_queue);
-	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
+	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen, cpu)) {
 		if (skb_queue_len(&sd->input_pkt_queue)) {
 enqueue:
 			__skb_queue_tail(&sd->input_pkt_queue, skb);
-- 
2.1.0