From fa6e393dc5b6e23b1638abe7b53bf0e25f73bea4 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 27 Sep 2010 00:38:18 +0000 Subject: [PATCH] sit: percpu stats accounting Maintain per_cpu tx_bytes, tx_packets, rx_bytes, rx_packets. Other seldom used fields are kept in netdev->stats structure, possibly unsafe. This is a preliminary work to support lockless transmit path, and correct RX stats, that are already unsafe. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/sit.c | 82 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 64 insertions(+), 18 deletions(-) diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 8a03998222306..011ecf55d34e9 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -63,8 +63,9 @@ #define HASH_SIZE 16 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) -static void ipip6_tunnel_init(struct net_device *dev); +static int ipip6_tunnel_init(struct net_device *dev); static void ipip6_tunnel_setup(struct net_device *dev); +static void ipip6_dev_free(struct net_device *dev); static int sit_net_id __read_mostly; struct sit_net { @@ -84,6 +85,33 @@ struct sit_net { #define for_each_ip_tunnel_rcu(start) \ for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) +/* often modified stats are per cpu, other are shared (netdev->stats) */ +struct pcpu_tstats { + unsigned long rx_packets; + unsigned long rx_bytes; + unsigned long tx_packets; + unsigned long tx_bytes; +}; + +static struct net_device_stats *ipip6_get_stats(struct net_device *dev) +{ + struct pcpu_tstats sum = { 0 }; + int i; + + for_each_possible_cpu(i) { + const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); + + sum.rx_packets += tstats->rx_packets; + sum.rx_bytes += tstats->rx_bytes; + sum.tx_packets += tstats->tx_packets; + sum.tx_bytes += tstats->tx_bytes; + } + dev->stats.rx_packets = sum.rx_packets; + dev->stats.rx_bytes = sum.rx_bytes; + dev->stats.tx_packets = sum.tx_packets; + dev->stats.tx_bytes = sum.tx_bytes; + return &dev->stats; +} /* * Must be invoked with rcu_read_lock */ @@ -214,7 +242,7 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, if (parms->name[0]) strlcpy(name, parms->name, IFNAMSIZ); else - sprintf(name, "sit%%d"); + strcpy(name, "sit%d"); dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); if (dev == NULL) @@ -230,7 +258,8 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, nt = netdev_priv(dev); nt->parms = *parms; - ipip6_tunnel_init(dev); + if (ipip6_tunnel_init(dev) < 0) + goto failed_free; ipip6_tunnel_clone_6rd(dev, sitn); if (parms->i_flags & SIT_ISATAP) @@ -245,7 +274,7 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, return nt; failed_free: - free_netdev(dev); + ipip6_dev_free(dev); failed: return NULL; } @@ -546,6 +575,8 @@ static int ipip6_rcv(struct sk_buff *skb) tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->saddr, iph->daddr); if (tunnel != NULL) { + struct pcpu_tstats *tstats; + secpath_reset(skb); skb->mac_header = skb->network_header; skb_reset_network_header(skb); @@ -561,7 +592,11 @@ static int ipip6_rcv(struct sk_buff *skb) return 0; } - skb_tunnel_rx(skb, tunnel->dev); + tstats = this_cpu_ptr(tunnel->dev->tstats); + tstats->rx_packets++; + tstats->rx_bytes += skb->len; + + __skb_tunnel_rx(skb, tunnel->dev); ipip6_ecn_decapsulate(iph, skb); @@ -626,14 +661,13 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); - struct net_device_stats *stats = &dev->stats; - struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); + struct pcpu_tstats *tstats; struct iphdr *tiph = &tunnel->parms.iph; struct ipv6hdr *iph6 = ipv6_hdr(skb); u8 tos = tunnel->parms.iph.tos; __be16 df = tiph->frag_off; struct rtable *rt; /* Route to the other host */ - struct net_device *tdev; /* Device to other host */ + struct net_device *tdev; /* Device to other host */ struct iphdr *iph; /* Our new IP header */ unsigned int max_headroom; /* The extra header space needed */ __be32 dst = tiph->daddr; @@ -704,20 +738,20 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, .oif = tunnel->parms.link, .proto = IPPROTO_IPV6 }; if (ip_route_output_key(dev_net(dev), &rt, &fl)) { - stats->tx_carrier_errors++; + dev->stats.tx_carrier_errors++; goto tx_error_icmp; } } if (rt->rt_type != RTN_UNICAST) { ip_rt_put(rt); - stats->tx_carrier_errors++; + dev->stats.tx_carrier_errors++; goto tx_error_icmp; } tdev = rt->dst.dev; if (tdev == dev) { ip_rt_put(rt); - stats->collisions++; + dev->stats.collisions++; goto tx_error; } @@ -725,7 +759,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); if (mtu < 68) { - stats->collisions++; + dev->stats.collisions++; ip_rt_put(rt); goto tx_error; } @@ -764,7 +798,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); if (!new_skb) { ip_rt_put(rt); - txq->tx_dropped++; + dev->stats.tx_dropped++; dev_kfree_skb(skb); return NETDEV_TX_OK; } @@ -800,14 +834,14 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, iph->ttl = iph6->hop_limit; nf_reset(skb); - - IPTUNNEL_XMIT(); + tstats = this_cpu_ptr(dev->tstats); + __IPTUNNEL_XMIT(tstats, &dev->stats); return NETDEV_TX_OK; tx_error_icmp: dst_link_failure(skb); tx_error: - stats->tx_errors++; + dev->stats.tx_errors++; dev_kfree_skb(skb); return NETDEV_TX_OK; } @@ -1084,12 +1118,19 @@ static const struct net_device_ops ipip6_netdev_ops = { .ndo_start_xmit = ipip6_tunnel_xmit, .ndo_do_ioctl = ipip6_tunnel_ioctl, .ndo_change_mtu = ipip6_tunnel_change_mtu, + .ndo_get_stats = ipip6_get_stats, }; +static void ipip6_dev_free(struct net_device *dev) +{ + free_percpu(dev->tstats); + free_netdev(dev); +} + static void ipip6_tunnel_setup(struct net_device *dev) { dev->netdev_ops = &ipip6_netdev_ops; - dev->destructor = free_netdev; + dev->destructor = ipip6_dev_free; dev->type = ARPHRD_SIT; dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); @@ -1101,7 +1142,7 @@ static void ipip6_tunnel_setup(struct net_device *dev) dev->features |= NETIF_F_NETNS_LOCAL; } -static void ipip6_tunnel_init(struct net_device *dev) +static int ipip6_tunnel_init(struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); @@ -1112,6 +1153,11 @@ static void ipip6_tunnel_init(struct net_device *dev) memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); ipip6_tunnel_bind_dev(dev); + dev->tstats = alloc_percpu(struct pcpu_tstats); + if (!dev->tstats) + return -ENOMEM; + + return 0; } static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) -- 2.39.5