net: dsa: User per-cpu 64-bit statistics
During testing with a background iperf pushing 1Gbit/sec worth of
traffic and having both ifconfig and ethtool collect statistics, we
could see quite frequent deadlocks. Convert the often accessed DSA slave
network devices statistics to per-cpu 64-bit statistics to remove these
deadlocks and provide fast efficient statistics updates.
Fixes: f613ed665bb3 ("net: dsa: Add support for 64-bit statistics")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 0ba842c..a91e520 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -190,6 +190,7 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
{
struct dsa_switch_tree *dst = dev->dsa_ptr;
struct sk_buff *nskb = NULL;
+ struct pcpu_sw_netstats *s;
struct dsa_slave_priv *p;
if (unlikely(dst == NULL)) {
@@ -213,10 +214,11 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, skb->dev);
- u64_stats_update_begin(&p->stats64.syncp);
- p->stats64.rx_packets++;
- p->stats64.rx_bytes += skb->len;
- u64_stats_update_end(&p->stats64.syncp);
+ s = this_cpu_ptr(p->stats64);
+ u64_stats_update_begin(&s->syncp);
+ s->rx_packets++;
+ s->rx_bytes += skb->len;
+ u64_stats_update_end(&s->syncp);
netif_receive_skb(skb);