From 63a664b7e92b14aaa1e1c3e9ae362aa70cf4cefb Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 25 May 2016 09:50:36 -0700 Subject: [PATCH] net/mlx4_en: fix tx_dropped bug 1) mlx4_en_xmit() can increment priv->stats.tx_dropped, but this variable is overwritten in mlx4_en_DUMP_ETH_STATS(). 2) This increment was not SMP safe, as a port might have many TX queues. Add a per TX ring tx_dropped to fix these issues. This is u32 as mlx4_en_DUMP_ETH_STATS() will add a 32bit field. So lets avoid bugs with SNMP agents having to cope with partial overwraps. (One of these agents being bond_fold_stats()) Signed-off-by: Eric Dumazet Reported-by: Willem de Bruijn Cc: Eugenia Emantayev Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 1 + drivers/net/ethernet/mellanox/mlx4/en_port.c | 4 +++- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 8 ++++---- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 + 4 files changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index 92e0624f4cf0..cfd50206f7c3 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -1892,6 +1892,7 @@ static void mlx4_en_clear_stats(struct net_device *dev) priv->tx_ring[i]->bytes = 0; priv->tx_ring[i]->packets = 0; priv->tx_ring[i]->tx_csum = 0; + priv->tx_ring[i]->tx_dropped = 0; } for (i = 0; i < priv->rx_ring_num; i++) { priv->rx_ring[i]->bytes = 0; diff --git a/drivers/net/ethernet/mellanox/mlx4/en_port.c b/drivers/net/ethernet/mellanox/mlx4/en_port.c index 20b6c2e678b8..3df8690154b1 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_port.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_port.c @@ -188,6 +188,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset) } stats->tx_packets = 0; stats->tx_bytes = 0; + stats->tx_dropped = 0; priv->port_stats.tx_chksum_offload = 0; priv->port_stats.queue_stopped = 0; priv->port_stats.wake_queue = 0; @@ -199,6 +200,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset) stats->tx_packets += ring->packets; stats->tx_bytes += ring->bytes; + stats->tx_dropped += ring->tx_dropped; priv->port_stats.tx_chksum_offload += ring->tx_csum; priv->port_stats.queue_stopped += ring->queue_stopped; priv->port_stats.wake_queue += ring->wake_queue; @@ -251,7 +253,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset) stats->tx_fifo_errors = 0; stats->tx_heartbeat_errors = 0; stats->tx_window_errors = 0; - stats->tx_dropped = be32_to_cpu(mlx4_en_stats->TDROP); + stats->tx_dropped += be32_to_cpu(mlx4_en_stats->TDROP); /* RX stats */ priv->pkstats.rx_multicast_packets = stats->multicast; diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index f6e61570cb2c..76aa4d27183c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -726,12 +726,12 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) bool inline_ok; u32 ring_cons; - if (!priv->port_up) - goto tx_drop; - tx_ind = skb_get_queue_mapping(skb); ring = priv->tx_ring[tx_ind]; + if (!priv->port_up) + goto tx_drop; + /* fetch ring->cons far ahead before needing it to avoid stall */ ring_cons = ACCESS_ONCE(ring->cons); @@ -1030,7 +1030,7 @@ tx_drop_unmap: tx_drop: dev_kfree_skb_any(skb); - priv->stats.tx_dropped++; + ring->tx_dropped++; return NETDEV_TX_OK; } diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index cc84e09f324a..9a9124031fc7 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -270,6 +270,7 @@ struct mlx4_en_tx_ring { unsigned long tx_csum; unsigned long tso_packets; unsigned long xmit_more; + unsigned int tx_dropped; struct mlx4_bf bf; unsigned long queue_stopped; -- 2.20.1