From 5f6b4e14cada6ddc662b80cbd670d9cd2922aea1 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 3 Aug 2017 21:33:27 -0700 Subject: net: dsa: User per-cpu 64-bit statistics During testing with a background iperf pushing 1Gbit/sec worth of traffic and having both ifconfig and ethtool collect statistics, we could see quite frequent deadlocks. Convert the often accessed DSA slave network devices statistics to per-cpu 64-bit statistics to remove these deadlocks and provide fast efficient statistics updates. Fixes: f613ed665bb3 ("net: dsa: Add support for 64-bit statistics") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/dsa.c | 10 +++++--- net/dsa/dsa_priv.h | 2 +- net/dsa/slave.c | 72 +++++++++++++++++++++++++++++++++++++++--------------- 3 files changed, 59 insertions(+), 25 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 0ba842c08dd3..a91e520e735f 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -190,6 +190,7 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev, { struct dsa_switch_tree *dst = dev->dsa_ptr; struct sk_buff *nskb = NULL; + struct pcpu_sw_netstats *s; struct dsa_slave_priv *p; if (unlikely(dst == NULL)) { @@ -213,10 +214,11 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev, skb->pkt_type = PACKET_HOST; skb->protocol = eth_type_trans(skb, skb->dev); - u64_stats_update_begin(&p->stats64.syncp); - p->stats64.rx_packets++; - p->stats64.rx_bytes += skb->len; - u64_stats_update_end(&p->stats64.syncp); + s = this_cpu_ptr(p->stats64); + u64_stats_update_begin(&s->syncp); + s->rx_packets++; + s->rx_bytes += skb->len; + u64_stats_update_end(&s->syncp); netif_receive_skb(skb); diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 7aa0656296c2..306cff229def 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -77,7 +77,7 @@ struct dsa_slave_priv { struct sk_buff * (*xmit)(struct sk_buff *skb, struct net_device *dev); - struct pcpu_sw_netstats stats64; + struct pcpu_sw_netstats *stats64; /* DSA port data, such as switch, port index, etc. */ struct dsa_port *dp; diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 83252e8426d7..75c5c5808220 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -352,12 +352,14 @@ static inline netdev_tx_t dsa_netpoll_send_skb(struct dsa_slave_priv *p, static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_slave_priv *p = netdev_priv(dev); + struct pcpu_sw_netstats *s; struct sk_buff *nskb; - u64_stats_update_begin(&p->stats64.syncp); - p->stats64.tx_packets++; - p->stats64.tx_bytes += skb->len; - u64_stats_update_end(&p->stats64.syncp); + s = this_cpu_ptr(p->stats64); + u64_stats_update_begin(&s->syncp); + s->tx_packets++; + s->tx_bytes += skb->len; + u64_stats_update_end(&s->syncp); /* Transmit function may have to reallocate the original SKB, * in which case it must have freed it. Only free it here on error. @@ -596,15 +598,26 @@ static void dsa_slave_get_ethtool_stats(struct net_device *dev, { struct dsa_slave_priv *p = netdev_priv(dev); struct dsa_switch *ds = p->dp->ds; + struct pcpu_sw_netstats *s; unsigned int start; - - do { - start = u64_stats_fetch_begin_irq(&p->stats64.syncp); - data[0] = p->stats64.tx_packets; - data[1] = p->stats64.tx_bytes; - data[2] = p->stats64.rx_packets; - data[3] = p->stats64.rx_bytes; - } while (u64_stats_fetch_retry_irq(&p->stats64.syncp, start)); + int i; + + for_each_possible_cpu(i) { + u64 tx_packets, tx_bytes, rx_packets, rx_bytes; + + s = per_cpu_ptr(p->stats64, i); + do { + start = u64_stats_fetch_begin_irq(&s->syncp); + tx_packets = s->tx_packets; + tx_bytes = s->tx_bytes; + rx_packets = s->rx_packets; + rx_bytes = s->rx_bytes; + } while (u64_stats_fetch_retry_irq(&s->syncp, start)); + data[0] += tx_packets; + data[1] += tx_bytes; + data[2] += rx_packets; + data[3] += rx_bytes; + } if (ds->ops->get_ethtool_stats) ds->ops->get_ethtool_stats(ds, p->dp->index, data + 4); } @@ -879,16 +892,28 @@ static void dsa_slave_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) { struct dsa_slave_priv *p = netdev_priv(dev); + struct pcpu_sw_netstats *s; unsigned int start; + int i; netdev_stats_to_stats64(stats, &dev->stats); - do { - start = u64_stats_fetch_begin_irq(&p->stats64.syncp); - stats->tx_packets = p->stats64.tx_packets; - stats->tx_bytes = p->stats64.tx_bytes; - stats->rx_packets = p->stats64.rx_packets; - stats->rx_bytes = p->stats64.rx_bytes; - } while (u64_stats_fetch_retry_irq(&p->stats64.syncp, start)); + for_each_possible_cpu(i) { + u64 tx_packets, tx_bytes, rx_packets, rx_bytes; + + s = per_cpu_ptr(p->stats64, i); + do { + start = u64_stats_fetch_begin_irq(&s->syncp); + tx_packets = s->tx_packets; + tx_bytes = s->tx_bytes; + rx_packets = s->rx_packets; + rx_bytes = s->rx_bytes; + } while (u64_stats_fetch_retry_irq(&s->syncp, start)); + + stats->tx_packets += tx_packets; + stats->tx_bytes += tx_bytes; + stats->rx_packets += rx_packets; + stats->rx_bytes += rx_bytes; + } } void dsa_cpu_port_ethtool_init(struct ethtool_ops *ops) @@ -1202,7 +1227,11 @@ int dsa_slave_create(struct dsa_switch *ds, struct device *parent, slave_dev->vlan_features = master->vlan_features; p = netdev_priv(slave_dev); - u64_stats_init(&p->stats64.syncp); + p->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); + if (!p->stats64) { + free_netdev(slave_dev); + return -ENOMEM; + } p->dp = &ds->ports[port]; INIT_LIST_HEAD(&p->mall_tc_list); p->xmit = dst->tag_ops->xmit; @@ -1217,6 +1246,7 @@ int dsa_slave_create(struct dsa_switch *ds, struct device *parent, netdev_err(master, "error %d registering interface %s\n", ret, slave_dev->name); ds->ports[port].netdev = NULL; + free_percpu(p->stats64); free_netdev(slave_dev); return ret; } @@ -1227,6 +1257,7 @@ int dsa_slave_create(struct dsa_switch *ds, struct device *parent, if (ret) { netdev_err(master, "error %d setting up slave phy\n", ret); unregister_netdev(slave_dev); + free_percpu(p->stats64); free_netdev(slave_dev); return ret; } @@ -1249,6 +1280,7 @@ void dsa_slave_destroy(struct net_device *slave_dev) of_phy_deregister_fixed_link(port_dn); } unregister_netdev(slave_dev); + free_percpu(p->stats64); free_netdev(slave_dev); } -- cgit v1.2.3