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virtio-net: per cpu 64 bit stats (v2)
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Use per-cpu variables to maintain 64 bit statistics.

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
stephen hemminger authored and davem330 committed Jul 1, 2011
1 parent f984cec commit 3fa2a1d
Showing 1 changed file with 79 additions and 6 deletions.
85 changes: 79 additions & 6 deletions drivers/net/virtio_net.c
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Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,15 @@ module_param(gso, bool, 0444);

#define VIRTNET_SEND_COMMAND_SG_MAX 2

struct virtnet_stats {
struct u64_stats_sync syncp;
u64 tx_bytes;
u64 tx_packets;

u64 rx_bytes;
u64 rx_packets;
};

struct virtnet_info {
struct virtio_device *vdev;
struct virtqueue *rvq, *svq, *cvq;
Expand All @@ -56,6 +65,9 @@ struct virtnet_info {
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;

/* Active statistics */
struct virtnet_stats __percpu *stats;

/* Work struct for refilling if we run low on memory. */
struct delayed_work refill;

Expand Down Expand Up @@ -209,14 +221,14 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
skb->dev->stats.rx_length_errors++;
return -EINVAL;
}

page = virtqueue_get_buf(vi->rvq, &len);
if (!page) {
pr_debug("%s: rx error: %d buffers missing\n",
skb->dev->name, hdr->mhdr.num_buffers);
skb->dev->stats.rx_length_errors++;
return -EINVAL;
}

if (len > PAGE_SIZE)
len = PAGE_SIZE;

Expand All @@ -230,6 +242,7 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
{
struct virtnet_info *vi = netdev_priv(dev);
struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
struct sk_buff *skb;
struct page *page;
struct skb_vnet_hdr *hdr;
Expand Down Expand Up @@ -265,8 +278,11 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len)

hdr = skb_vnet_hdr(skb);
skb->truesize += skb->data_len;
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;

u64_stats_update_begin(&stats->syncp);
stats->rx_bytes += skb->len;
stats->rx_packets++;
u64_stats_update_end(&stats->syncp);

if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
pr_debug("Needs csum!\n");
Expand Down Expand Up @@ -515,11 +531,16 @@ static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
{
struct sk_buff *skb;
unsigned int len, tot_sgs = 0;
struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);

while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
pr_debug("Sent skb %p\n", skb);
vi->dev->stats.tx_bytes += skb->len;
vi->dev->stats.tx_packets++;

u64_stats_update_begin(&stats->syncp);
stats->tx_bytes += skb->len;
stats->tx_packets++;
u64_stats_update_end(&stats->syncp);

tot_sgs += skb_vnet_hdr(skb)->num_sg;
dev_kfree_skb_any(skb);
}
Expand Down Expand Up @@ -641,6 +662,40 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
return 0;
}

static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
struct rtnl_link_stats64 *tot)
{
struct virtnet_info *vi = netdev_priv(dev);
int cpu;
unsigned int start;

for_each_possible_cpu(cpu) {
struct virtnet_stats __percpu *stats
= per_cpu_ptr(vi->stats, cpu);
u64 tpackets, tbytes, rpackets, rbytes;

do {
start = u64_stats_fetch_begin(&stats->syncp);
tpackets = stats->tx_packets;
tbytes = stats->tx_bytes;
rpackets = stats->rx_packets;
rbytes = stats->rx_bytes;
} while (u64_stats_fetch_retry(&stats->syncp, start));

tot->rx_packets += rpackets;
tot->tx_packets += tpackets;
tot->rx_bytes += rbytes;
tot->tx_bytes += tbytes;
}

tot->tx_dropped = dev->stats.tx_dropped;
tot->rx_dropped = dev->stats.rx_dropped;
tot->rx_length_errors = dev->stats.rx_length_errors;
tot->rx_frame_errors = dev->stats.rx_frame_errors;

return tot;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void virtnet_netpoll(struct net_device *dev)
{
Expand All @@ -650,6 +705,14 @@ static void virtnet_netpoll(struct net_device *dev)
}
#endif

static void virtnet_free(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);

free_percpu(vi->stats);
free_netdev(dev);
}

static int virtnet_open(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
Expand Down Expand Up @@ -835,6 +898,7 @@ static const struct net_device_ops virtnet_netdev = {
.ndo_set_mac_address = virtnet_set_mac_address,
.ndo_set_rx_mode = virtnet_set_rx_mode,
.ndo_change_mtu = virtnet_change_mtu,
.ndo_get_stats64 = virtnet_stats,
.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
#ifdef CONFIG_NET_POLL_CONTROLLER
Expand Down Expand Up @@ -895,6 +959,8 @@ static int virtnet_probe(struct virtio_device *vdev)
/* Set up network device as normal. */
dev->netdev_ops = &virtnet_netdev;
dev->features = NETIF_F_HIGHDMA;
dev->destructor = virtnet_free;

SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
SET_NETDEV_DEV(dev, &vdev->dev);

Expand Down Expand Up @@ -939,6 +1005,11 @@ static int virtnet_probe(struct virtio_device *vdev)
vi->vdev = vdev;
vdev->priv = vi;
vi->pages = NULL;
vi->stats = alloc_percpu(struct virtnet_stats);
err = -ENOMEM;
if (vi->stats == NULL)
goto free;

INIT_DELAYED_WORK(&vi->refill, refill_work);
sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
Expand All @@ -958,7 +1029,7 @@ static int virtnet_probe(struct virtio_device *vdev)

err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
if (err)
goto free;
goto free_stats;

vi->rvq = vqs[0];
vi->svq = vqs[1];
Expand Down Expand Up @@ -1003,6 +1074,8 @@ static int virtnet_probe(struct virtio_device *vdev)
cancel_delayed_work_sync(&vi->refill);
free_vqs:
vdev->config->del_vqs(vdev);
free_stats:
free_percpu(vi->stats);
free:
free_netdev(dev);
return err;
Expand Down

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