diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-02-16 15:23:27 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-19 18:15:23 -0500 |
| commit | f5a57723371f11ff953c4ba71184dc00e65469fc (patch) | |
| tree | 38f76e696c6934a7c0ff3500f9c36bd581ca4d51 /drivers/net/ethernet/mellanox/mlx4/en_netdev.c | |
| parent | 1786dbf3702e33ce3afd2d3dbe630bd04b1d2e58 (diff) | |
mlx4: fix potential divide by 0 in mlx4_en_auto_moderation()
1) In the case where rate == priv->pkt_rate_low == priv->pkt_rate_high,
mlx4_en_auto_moderation() does a divide by zero.
2) We want to properly change the moderation parameters if rx_frames
was changed (like in ethtool -C eth0 rx-frames 16)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx4/en_netdev.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index 748e9f65c386..afe4444e5434 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -1382,6 +1382,7 @@ static void mlx4_en_set_default_moderation(struct mlx4_en_priv *priv) static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv) { unsigned long period = (unsigned long) (jiffies - priv->last_moder_jiffies); + u32 pkt_rate_high, pkt_rate_low; struct mlx4_en_cq *cq; unsigned long packets; unsigned long rate; @@ -1395,37 +1396,40 @@ static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv) if (!priv->adaptive_rx_coal || period < priv->sample_interval * HZ) return; + pkt_rate_low = READ_ONCE(priv->pkt_rate_low); + pkt_rate_high = READ_ONCE(priv->pkt_rate_high); + for (ring = 0; ring < priv->rx_ring_num; ring++) { rx_packets = READ_ONCE(priv->rx_ring[ring]->packets); rx_bytes = READ_ONCE(priv->rx_ring[ring]->bytes); - rx_pkt_diff = ((unsigned long) (rx_packets - - priv->last_moder_packets[ring])); + rx_pkt_diff = rx_packets - priv->last_moder_packets[ring]; packets = rx_pkt_diff; rate = packets * HZ / period; - avg_pkt_size = packets ? ((unsigned long) (rx_bytes - - priv->last_moder_bytes[ring])) / packets : 0; + avg_pkt_size = packets ? (rx_bytes - + priv->last_moder_bytes[ring]) / packets : 0; /* Apply auto-moderation only when packet rate * exceeds a rate that it matters */ if (rate > (MLX4_EN_RX_RATE_THRESH / priv->rx_ring_num) && avg_pkt_size > MLX4_EN_AVG_PKT_SMALL) { - if (rate < priv->pkt_rate_low) + if (rate <= pkt_rate_low) moder_time = priv->rx_usecs_low; - else if (rate > priv->pkt_rate_high) + else if (rate >= pkt_rate_high) moder_time = priv->rx_usecs_high; else - moder_time = (rate - priv->pkt_rate_low) * + moder_time = (rate - pkt_rate_low) * (priv->rx_usecs_high - priv->rx_usecs_low) / - (priv->pkt_rate_high - priv->pkt_rate_low) + + (pkt_rate_high - pkt_rate_low) + priv->rx_usecs_low; } else { moder_time = priv->rx_usecs_low; } - if (moder_time != priv->last_moder_time[ring]) { + cq = priv->rx_cq[ring]; + if (moder_time != priv->last_moder_time[ring] || + cq->moder_cnt != priv->rx_frames) { priv->last_moder_time[ring] = moder_time; - cq = priv->rx_cq[ring]; cq->moder_time = moder_time; cq->moder_cnt = priv->rx_frames; err = mlx4_en_set_cq_moder(priv, cq); |