Commit d99a7c2f authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by David S. Miller
Browse files

veth: remove atomic64_add from veth_xdp_xmit hotpath 



Remove atomic64_add from veth_xdp_xmit hotpath and rely on
xdp_xmit_err/xdp_tx_err counters

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9152cff0

drivers/net/veth.c

+17 −13
Original line number Diff line number Diff line
@@ -301,20 +301,26 @@ static void veth_stats_rx(struct veth_stats *result, struct net_device *dev) 
	struct veth_priv *priv = netdev_priv(dev);

	int i;



	result->xdp_xmit_err = 0;

	result->xdp_packets = 0;

	result->xdp_tx_err = 0;

	result->xdp_bytes = 0;

	result->rx_drops = 0;

	for (i = 0; i < dev->num_rx_queues; i++) {

		u64 packets, bytes, drops, xdp_tx_err, xdp_xmit_err;

		struct veth_rq_stats *stats = &priv->rq[i].stats;

		u64 packets, bytes, drops;

		unsigned int start;



		do {

			start = u64_stats_fetch_begin_irq(&stats->syncp);

			xdp_xmit_err = stats->vs.xdp_xmit_err;

			xdp_tx_err = stats->vs.xdp_tx_err;

			packets = stats->vs.xdp_packets;

			bytes = stats->vs.xdp_bytes;

			drops = stats->vs.rx_drops;

		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));

		result->xdp_xmit_err += xdp_xmit_err;

		result->xdp_tx_err += xdp_tx_err;

		result->xdp_packets += packets;

		result->xdp_bytes += bytes;

		result->rx_drops += drops;
@@ -334,6 +340,7 @@ static void veth_get_stats64(struct net_device *dev, 
	tot->tx_packets = packets;



	veth_stats_rx(&rx, dev);

	tot->tx_dropped += rx.xdp_xmit_err + rx.xdp_tx_err;

	tot->rx_dropped = rx.rx_drops;

	tot->rx_bytes = rx.xdp_bytes;

	tot->rx_packets = rx.xdp_packets;
@@ -346,6 +353,7 @@ static void veth_get_stats64(struct net_device *dev, 
		tot->rx_packets += packets;



		veth_stats_rx(&rx, peer);

		tot->rx_dropped += rx.xdp_xmit_err + rx.xdp_tx_err;

		tot->tx_bytes += rx.xdp_bytes;

		tot->tx_packets += rx.xdp_packets;

	}
@@ -393,14 +401,16 @@ static int veth_xdp_xmit(struct net_device *dev, int n, 


	rcu_read_lock();

	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {

		ret = -EINVAL;

		goto drop;

		rcu_read_unlock();

		atomic64_add(drops, &priv->dropped);

		return -EINVAL;

	}



	rcv = rcu_dereference(priv->peer);

	if (unlikely(!rcv)) {

		ret = -ENXIO;

		goto drop;

		rcu_read_unlock();

		atomic64_add(drops, &priv->dropped);

		return -ENXIO;

	}



	rcv_priv = netdev_priv(rcv);
@@ -434,6 +444,8 @@ static int veth_xdp_xmit(struct net_device *dev, int n, 
	if (flags & XDP_XMIT_FLUSH)

		__veth_xdp_flush(rq);



	ret = n - drops;

drop:

	rq = &priv->rq[qidx];

	u64_stats_update_begin(&rq->stats.syncp);

	if (ndo_xmit) {
@@ -445,15 +457,7 @@ static int veth_xdp_xmit(struct net_device *dev, int n, 
	}

	u64_stats_update_end(&rq->stats.syncp);



	if (likely(!drops)) {

		rcu_read_unlock();

		return n;

	}



	ret = n - drops;

drop:

	rcu_read_unlock();

	atomic64_add(drops, &priv->dropped);



	return ret;

}