From: Stephen Hemminger <shemminger@xxxxxxxxxx>
Le lundi 01 mars 2010 à 16:16 -0800, Stephen Hemminger a écrit :
> + for_each_online_cpu(cpu) {
> + const struct br_cpu_netstats *bstats
> + = per_cpu_ptr(br->stats, cpu);
> +
> + stats->rx_bytes += bstats->rx_bytes;
> + stats->rx_packets += bstats->rx_packets;
> + }
And last point, we should use for_each_possible_cpu() here
Here is your patch with all my comments integrated :
1) Use txq->{tx_bytes|tx_packets} counter
2) alloc_percpu(struct ...) instead of alloc_percpu(sizeof(struct ...))
3) free_netdev() in destructor
4) for_each_possible_cpu() instead of for_each_online_cpu()
5) br_get_stats() use local variables for the sake of concurrent users
Next step would be to use multiqueue :)
Thanks
[PATCH] bridge: per-cpu packet statistics
The shared packet statistics are a potential source of slow down
on bridged traffic. Convert to per-cpu array for rx_packets/rx_bytes RX
accounting, and use txq tx_packets/tx_bytes for TX accounting
Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
---
net/bridge/br_device.c | 39 +++++++++++++++++++++++++++++++++++---
net/bridge/br_if.c | 6 +++++
net/bridge/br_input.c | 6 +++--
net/bridge/br_private.h | 6 +++++
4 files changed, 52 insertions(+), 5 deletions(-)
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index eb7062d..e73c42c 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -22,6 +22,8 @@
/* net device transmit always called with no BH (preempt_disabled) */
netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
+ int qidx = skb_get_queue_mapping(skb);
+ struct netdev_queue *txq = netdev_get_tx_queue(dev, qidx);
struct net_bridge *br = netdev_priv(dev);
const unsigned char *dest = skb->data;
struct net_bridge_fdb_entry *dst;
@@ -29,8 +31,8 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
BR_INPUT_SKB_CB(skb)->brdev = dev;
- dev->stats.tx_packets++;
- dev->stats.tx_bytes += skb->len;
+ txq->tx_packets++;
+ txq->tx_bytes += skb->len;
skb_reset_mac_header(skb);
skb_pull(skb, ETH_HLEN);
@@ -81,6 +83,28 @@ static int br_dev_stop(struct net_device *dev)
return 0;
}
+static struct net_device_stats *br_get_stats(struct net_device *dev)
+{
+ struct net_bridge *br = netdev_priv(dev);
+ struct net_device_stats *stats = &dev->stats;
+ unsigned long rx_bytes = 0, rx_packets = 0;
+ unsigned int cpu;
+
+ dev_txq_stats_fold(dev, stats);
+
+ for_each_possible_cpu(cpu) {
+ const struct br_cpu_netstats *bstats
+ = per_cpu_ptr(br->stats, cpu);
+
+ rx_bytes += bstats->rx_bytes;
+ rx_packets += bstats->rx_packets;
+ }
+ stats->rx_bytes = rx_bytes;
+ stats->rx_packets = rx_packets;
+
+ return stats;
+}
+
static int br_change_mtu(struct net_device *dev, int new_mtu)
{
struct net_bridge *br = netdev_priv(dev);
@@ -180,19 +204,28 @@ static const struct net_device_ops br_netdev_ops = {
.ndo_open = br_dev_open,
.ndo_stop = br_dev_stop,
.ndo_start_xmit = br_dev_xmit,
+ .ndo_get_stats = br_get_stats,
.ndo_set_mac_address = br_set_mac_address,
.ndo_set_multicast_list = br_dev_set_multicast_list,
.ndo_change_mtu = br_change_mtu,
.ndo_do_ioctl = br_dev_ioctl,
};
+static void br_dev_free(struct net_device *dev)
+{
+ struct net_bridge *br = netdev_priv(dev);
+
+ free_percpu(br->stats);
+ free_netdev(dev);
+}
+
void br_dev_setup(struct net_device *dev)
{
random_ether_addr(dev->dev_addr);
ether_setup(dev);
dev->netdev_ops = &br_netdev_ops;
- dev->destructor = free_netdev;
+ dev->destructor = br_dev_free;
SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
dev->tx_queue_len = 0;
dev->priv_flags = IFF_EBRIDGE;
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index b6a3872..b7cdd2e 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -185,6 +185,12 @@ static struct net_device *new_bridge_dev(struct net *net, const char *name)
br = netdev_priv(dev);
br->dev = dev;
+ br->stats = alloc_percpu(struct br_cpu_netstats);
+ if (!br->stats) {
+ free_netdev(dev);
+ return NULL;
+ }
+
spin_lock_init(&br->lock);
INIT_LIST_HEAD(&br->port_list);
spin_lock_init(&br->hash_lock);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 53b3985..7a5a5b4 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -23,9 +23,11 @@ const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
static int br_pass_frame_up(struct sk_buff *skb)
{
struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
+ struct net_bridge *br = netdev_priv(brdev);
+ struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
- brdev->stats.rx_packets++;
- brdev->stats.rx_bytes += skb->len;
+ brstats->rx_packets++;
+ brstats->rx_bytes += skb->len;
indev = skb->dev;
skb->dev = brdev;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 9191198..06b30af 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -135,6 +135,12 @@ struct net_bridge
spinlock_t lock;
struct list_head port_list;
struct net_device *dev;
+
+ struct br_cpu_netstats __percpu {
+ unsigned long rx_bytes;
+ unsigned long rx_packets;
+ } *stats;
+
spinlock_t hash_lock;
struct hlist_head hash[BR_HASH_SIZE];
unsigned long feature_mask;
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