On Tue, 2011-06-21 at 16:35 +0100, Stephen Hemminger wrote:
> Convert xen driver to 64 bit statistics interface.
> Use stats_sync to ensure that 64 bit update is read atomically on 32 bit
> platform.
> Put hot statistics into per-cpu table.
>
> Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
>
> ---
> v2 - add stats_sync and per-cpu
> v2.1 - keep rx_errors on checksum error
Thanks. Looks good to me from the Xen side.
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
>
> --- a/drivers/net/xen-netfront.c 2011-06-20 14:50:01.271989938 -0700
> +++ b/drivers/net/xen-netfront.c 2011-06-21 08:33:12.851953760 -0700
> @@ -70,6 +70,14 @@ struct netfront_cb {
> #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
> #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
>
> +struct netfront_stats {
> + u64 rx_packets;
> + u64 tx_packets;
> + u64 rx_bytes;
> + u64 tx_bytes;
> + struct u64_stats_sync syncp;
> +};
> +
> struct netfront_info {
> struct list_head list;
> struct net_device *netdev;
> @@ -122,6 +130,8 @@ struct netfront_info {
> struct mmu_update rx_mmu[NET_RX_RING_SIZE];
>
> /* Statistics */
> + struct netfront_stats __percpu *stats;
> +
> unsigned long rx_gso_checksum_fixup;
> };
>
> @@ -468,6 +478,7 @@ static int xennet_start_xmit(struct sk_b
> {
> unsigned short id;
> struct netfront_info *np = netdev_priv(dev);
> + struct netfront_stats *stats = this_cpu_ptr(np->stats);
> struct xen_netif_tx_request *tx;
> struct xen_netif_extra_info *extra;
> char *data = skb->data;
> @@ -552,8 +563,10 @@ static int xennet_start_xmit(struct sk_b
> if (notify)
> notify_remote_via_irq(np->netdev->irq);
>
> - dev->stats.tx_bytes += skb->len;
> - dev->stats.tx_packets++;
> + u64_stats_update_begin(&stats->syncp);
> + stats->tx_bytes += skb->len;
> + stats->tx_packets++;
> + u64_stats_update_end(&stats->syncp);
>
> /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
> xennet_tx_buf_gc(dev);
> @@ -847,6 +860,8 @@ out:
> static int handle_incoming_queue(struct net_device *dev,
> struct sk_buff_head *rxq)
> {
> + struct netfront_info *np = netdev_priv(dev);
> + struct netfront_stats *stats = this_cpu_ptr(np->stats);
> int packets_dropped = 0;
> struct sk_buff *skb;
>
> @@ -871,8 +886,10 @@ static int handle_incoming_queue(struct
> continue;
> }
>
> - dev->stats.rx_packets++;
> - dev->stats.rx_bytes += skb->len;
> + u64_stats_update_begin(&stats->syncp);
> + stats->rx_packets++;
> + stats->rx_bytes += skb->len;
> + u64_stats_update_end(&stats->syncp);
>
> /* Pass it up. */
> netif_receive_skb(skb);
> @@ -1034,6 +1051,38 @@ static int xennet_change_mtu(struct net_
> return 0;
> }
>
> +static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
> + struct rtnl_link_stats64
> *tot)
> +{
> + struct netfront_info *np = netdev_priv(dev);
> + int cpu;
> +
> + for_each_possible_cpu(cpu) {
> + struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
> + u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
> + unsigned int start;
> +
> + do {
> + start = u64_stats_fetch_begin_bh(&stats->syncp);
> +
> + rx_packets = stats->rx_packets;
> + tx_packets = stats->tx_packets;
> + rx_bytes = stats->rx_bytes;
> + tx_bytes = stats->tx_bytes;
> + } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
> +
> + tot->rx_packets += rx_packets;
> + tot->tx_packets += tx_packets;
> + tot->rx_bytes += rx_bytes;
> + tot->tx_bytes += tx_bytes;
> + }
> +
> + tot->rx_errors = dev->stats.rx_errors;
> + tot->tx_dropped = dev->stats.tx_dropped;
> +
> + return tot;
> +}
> +
> static void xennet_release_tx_bufs(struct netfront_info *np)
> {
> struct sk_buff *skb;
> @@ -1182,6 +1231,7 @@ static const struct net_device_ops xenne
> .ndo_stop = xennet_close,
> .ndo_start_xmit = xennet_start_xmit,
> .ndo_change_mtu = xennet_change_mtu,
> + .ndo_get_stats64 = xennet_get_stats64,
> .ndo_set_mac_address = eth_mac_addr,
> .ndo_validate_addr = eth_validate_addr,
> .ndo_fix_features = xennet_fix_features,
> @@ -1216,6 +1266,11 @@ static struct net_device * __devinit xen
> np->rx_refill_timer.data = (unsigned long)netdev;
> np->rx_refill_timer.function = rx_refill_timeout;
>
> + err = -ENOMEM;
> + np->stats = alloc_percpu(struct netfront_stats);
> + if (np->stats == NULL)
> + goto exit;
> +
> /* Initialise tx_skbs as a free chain containing every entry. */
> np->tx_skb_freelist = 0;
> for (i = 0; i < NET_TX_RING_SIZE; i++) {
> @@ -1234,7 +1289,7 @@ static struct net_device * __devinit xen
> &np->gref_tx_head) < 0) {
> printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
> err = -ENOMEM;
> - goto exit;
> + goto exit_free_stats;
> }
> /* A grant for every rx ring slot */
> if (gnttab_alloc_grant_references(RX_MAX_TARGET,
> @@ -1270,6 +1325,8 @@ static struct net_device * __devinit xen
>
> exit_free_tx:
> gnttab_free_grant_references(np->gref_tx_head);
> + exit_free_stats:
> + free_percpu(np->stats);
> exit:
> free_netdev(netdev);
> return ERR_PTR(err);
> @@ -1869,6 +1926,8 @@ static int __devexit xennet_remove(struc
>
> xennet_sysfs_delif(info->netdev);
>
> + free_percpu(info->stats);
> +
> free_netdev(info->netdev);
>
> return 0;
>
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