From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Thu, 19 Mar 2020 17:41:29 +0100
Subject: veth: remove atomic64_add from veth_xdp_xmit hotpath
Patch-mainline: v5.7-rc1
Git-commit: d99a7c2f3d0e65d3906bd7cf719223b0f8b5b481
References: bsc#1176447
Remove atomic64_add from veth_xdp_xmit hotpath and rely on
xdp_xmit_err/xdp_tx_err counters
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/veth.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -301,20 +301,26 @@ static void veth_stats_rx(struct veth_st
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_
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_
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_devi
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_devi
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_devi
}
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;
}