Commit b9972d22 authored Nov 23, 2016 by Eric Dumazet Committed by David S. Miller Nov 27, 2016

mlx4: do not use priv->stats_lock in mlx4_en_auto_moderation()



Per RX ring packets/bytes counters are not protected by global
priv->stats_lock.

Better not confuse the reader, and use READ_ONCE() to show we read
these counters without surrounding synchronization.

Interrupt moderation is best effort, and we do not really care of
ultra precise counters.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0b42f25d

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -1394,10 +1394,8 @@ static void mlx4_en_auto_moderation(struct mlx4_en_priv *priv)
		return;

		for (ring = 0; ring < priv->rx_ring_num; ring++) {
		spin_lock_bh(&priv->stats_lock);
		rx_packets = priv->rx_ring[ring]->packets;
		rx_bytes = priv->rx_ring[ring]->bytes;
		spin_unlock_bh(&priv->stats_lock);
		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]));

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