veth: remove atomic64_add from veth_xdp_xmit hotpath (d99a7c2f) · Commits · 戴 / test

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;
		}

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