[PATCH net-next 1/1] driver: veth: Refine the statistics codes of veth driver

[fgao]

From: Gao Feng <f...@ikuai8.com>

The dropped count of veth is located in struct veth_priv, but other
statistics like packets and bytes are in another struct pcpu_vstats.
Now keep these three counters in the same struct.

Signed-off-by: Gao Feng <f...@ikuai8.com>
---
 drivers/net/veth.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 0520952a..3d8326f 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -26,12 +26,12 @@
 struct pcpu_vstats {
        u64                     packets;
        u64                     bytes;
+       u64                     dropped;
        struct u64_stats_sync   syncp;
 };
 
 struct veth_priv {
        struct net_device __rcu *peer;
-       atomic64_t              dropped;
        unsigned                requested_headroom;
 };
 
@@ -108,6 +108,8 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct 
net_device *dev)
        struct veth_priv *priv = netdev_priv(dev);
        struct net_device *rcv;
        int length = skb->len;
+       struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
+       int ret = NET_RX_DROP;
 
        rcu_read_lock();
        rcv = rcu_dereference(priv->peer);
@@ -116,17 +118,16 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct 
net_device *dev)
                goto drop;
        }
 
-       if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
-               struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
-
-               u64_stats_update_begin(&stats->syncp);
+       ret = dev_forward_skb(rcv, skb);
+drop:
+       u64_stats_update_begin(&stats->syncp);
+       if (likely(ret == NET_RX_SUCCESS)) {
                stats->bytes += length;
                stats->packets++;
-               u64_stats_update_end(&stats->syncp);
        } else {
-drop:
-               atomic64_inc(&priv->dropped);
+               stats->dropped++;
        }
+       u64_stats_update_end(&stats->syncp);
        rcu_read_unlock();
        return NETDEV_TX_OK;
 }
@@ -135,27 +136,28 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct 
net_device *dev)
  * general routines
  */
 
-static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
+static void veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
 {
-       struct veth_priv *priv = netdev_priv(dev);
        int cpu;
 
        result->packets = 0;
        result->bytes = 0;
+       result->dropped = 0;
        for_each_possible_cpu(cpu) {
                struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
-               u64 packets, bytes;
+               u64 packets, bytes, dropped;
                unsigned int start;
 
                do {
                        start = u64_stats_fetch_begin_irq(&stats->syncp);
                        packets = stats->packets;
                        bytes = stats->bytes;
+                       dropped = stats->dropped;
                } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
                result->packets += packets;
                result->bytes += bytes;
+               result->dropped += dropped;
        }
-       return atomic64_read(&priv->dropped);
 }
 
 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
@@ -165,16 +167,18 @@ static struct rtnl_link_stats64 *veth_get_stats64(struct 
net_device *dev,
        struct net_device *peer;
        struct pcpu_vstats one;
 
-       tot->tx_dropped = veth_stats_one(&one, dev);
+       veth_stats_one(&one, dev);
        tot->tx_bytes = one.bytes;
        tot->tx_packets = one.packets;
+       tot->tx_dropped = one.dropped;
 
        rcu_read_lock();
        peer = rcu_dereference(priv->peer);
        if (peer) {
-               tot->rx_dropped = veth_stats_one(&one, peer);
+               veth_stats_one(&one, dev);
                tot->rx_bytes = one.bytes;
                tot->rx_packets = one.packets;
+               tot->rx_dropped = one.dropped;
        }
        rcu_read_unlock();
 
-- 
1.9.1