Satistics counters is useful for debugging and performance optimization, so this
patch lets virtio_net driver collect following and export them to userspace
through "ethtool -S":
- number of packets sent/received
- number of bytes sent/received
- number of callbacks for tx/rx
- number of kick for tx/rx
- number of bytes/packets queued for tx
As virtnet_stats were per-cpu, so both per-cpu and gloabl satistics were exposed
like:
NIC statistics:
tx_bytes[0]: 2551
tx_packets[0]: 12
tx_kick[0]: 12
tx_callbacks[0]: 1
tx_queued_packets[0]: 12
tx_queued_bytes[0]: 3055
rx_bytes[0]: 0
rx_packets[0]: 0
rx_kick[0]: 0
rx_callbacks[0]: 0
tx_bytes[1]: 5575
tx_packets[1]: 37
tx_kick[1]: 38
tx_callbacks[1]: 0
tx_queued_packets[1]: 38
tx_queued_bytes[1]: 5217
rx_bytes[1]: 4175
rx_packets[1]: 25
rx_kick[1]: 1
rx_callbacks[1]: 16
tx_bytes: 8126
tx_packets: 49
tx_kick: 50
tx_callbacks: 1
tx_queued_packets: 50
tx_queued_bytes: 8272
rx_bytes: 4175
rx_packets: 25
rx_kick: 1
rx_callbacks: 16
TODO:
- more satistics
- unitfy the ndo_get_stats64 and get_ethtool_stats
- calculate the pending bytes/pkts
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 130 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 127 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5214b1e..7ab0cc1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -41,6 +41,10 @@ module_param(gso, bool, 0444);
#define VIRTNET_SEND_COMMAND_SG_MAX 2
#define VIRTNET_DRIVER_VERSION "1.0.0"
+#define VIRTNET_STAT_OFF(m) offsetof(struct virtnet_stats, m)
+#define VIRTNET_STAT(stat, i) (*((u64 *)((char *)stat + \
+ virtnet_stats_str_attr[i].stat_offset)))
+
struct virtnet_stats {
struct u64_stats_sync syncp;
u64 tx_bytes;
@@ -48,8 +52,33 @@ struct virtnet_stats {
u64 rx_bytes;
u64 rx_packets;
+
+ u64 tx_kick;
+ u64 rx_kick;
+ u64 tx_callbacks;
+ u64 rx_callbacks;
+ u64 tx_queued_packets;
+ u64 tx_queued_bytes;
+};
+
+static struct {
+ char string[ETH_GSTRING_LEN];
+ int stat_offset;
+} virtnet_stats_str_attr[] = {
+ { "tx_bytes", VIRTNET_STAT_OFF(tx_bytes)},
+ { "tx_packets", VIRTNET_STAT_OFF(tx_packets)},
+ { "tx_kick", VIRTNET_STAT_OFF(tx_kick)},
+ { "tx_callbacks", VIRTNET_STAT_OFF(tx_callbacks)},
+ { "tx_queued_packets", VIRTNET_STAT_OFF(tx_queued_packets)},
+ { "tx_queued_bytes", VIRTNET_STAT_OFF(tx_queued_bytes)},
+ { "rx_bytes" , VIRTNET_STAT_OFF(rx_bytes)},
+ { "rx_packets", VIRTNET_STAT_OFF(rx_packets)},
+ { "rx_kick", VIRTNET_STAT_OFF(rx_kick)},
+ { "rx_callbacks", VIRTNET_STAT_OFF(rx_callbacks)},
};
+#define VIRTNET_NUM_STATS ARRAY_SIZE(virtnet_stats_str_attr)
+
struct virtnet_info {
struct virtio_device *vdev;
struct virtqueue *rvq, *svq, *cvq;
@@ -142,6 +171,11 @@ static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
static void skb_xmit_done(struct virtqueue *svq)
{
struct virtnet_info *vi = svq->vdev->priv;
+ struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_callbacks++;
+ u64_stats_update_end(&stats->syncp);
/* Suppress further interrupts. */
virtqueue_disable_cb(svq);
@@ -461,6 +495,7 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
{
int err;
bool oom;
+ struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
do {
if (vi->mergeable_rx_bufs)
@@ -477,13 +512,24 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
} while (err > 0);
if (unlikely(vi->num > vi->max))
vi->max = vi->num;
- virtqueue_kick(vi->rvq);
+ if (virtqueue_kick_prepare(vi->rvq)) {
+ virtqueue_notify(vi->rvq);
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_kick++;
+ u64_stats_update_end(&stats->syncp);
+ }
return !oom;
}
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
+ struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_callbacks++;
+ u64_stats_update_end(&stats->syncp);
+
/* Schedule NAPI, Suppress further interrupts if successful. */
if (napi_schedule_prep(&vi->napi)) {
virtqueue_disable_cb(rvq);
@@ -626,7 +672,9 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
int capacity;
+ bool kick;
/* Free up any pending old buffers before queueing new ones. */
free_old_xmit_skbs(vi);
@@ -651,7 +699,17 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
kfree_skb(skb);
return NETDEV_TX_OK;
}
- virtqueue_kick(vi->svq);
+
+ kick = virtqueue_kick_prepare(vi->svq);
+ if (kick)
+ virtqueue_notify(vi->svq);
+
+ u64_stats_update_begin(&stats->syncp);
+ if (kick)
+ stats->tx_kick++;
+ stats->tx_queued_bytes += skb->len;
+ stats->tx_queued_packets++;
+ u64_stats_update_end(&stats->syncp);
/* Don't wait up for transmitted skbs to be freed. */
skb_orphan(skb);
@@ -926,7 +984,6 @@ static void virtnet_get_ringparam(struct net_device *dev,
}
-
static void virtnet_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
@@ -939,10 +996,77 @@ static void virtnet_get_drvinfo(struct net_device *dev,
}
+static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+ int i, cpu;
+ switch (stringset) {
+ case ETH_SS_STATS:
+ for_each_possible_cpu(cpu)
+ for (i = 0; i < VIRTNET_NUM_STATS; i++) {
+ sprintf(buf, "%s[%u]",
+ virtnet_stats_str_attr[i].string, cpu);
+ buf += ETH_GSTRING_LEN;
+ }
+ for (i = 0; i < VIRTNET_NUM_STATS; i++) {
+ memcpy(buf, virtnet_stats_str_attr[i].string,
+ ETH_GSTRING_LEN);
+ buf += ETH_GSTRING_LEN;
+ }
+ break;
+ }
+}
+
+static int virtnet_get_sset_count(struct net_device *dev, int sset)
+{
+ switch (sset) {
+ case ETH_SS_STATS:
+ return VIRTNET_NUM_STATS * (num_online_cpus() + 1);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static void virtnet_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *stats, u64 *buf)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ int cpu, i;
+ unsigned int start;
+ struct virtnet_stats sample, total;
+
+ memset(&total, 0, sizeof(total));
+ memset(&sample, 0, sizeof(sample));
+
+ for_each_possible_cpu(cpu) {
+ struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
+ do {
+ start = u64_stats_fetch_begin(&stats->syncp);
+ for (i = 0; i < VIRTNET_NUM_STATS; i++) {
+ VIRTNET_STAT(&sample, i) =
+ VIRTNET_STAT(stats, i);
+
+ }
+ } while (u64_stats_fetch_retry(&stats->syncp, start));
+ for (i = 0; i < VIRTNET_NUM_STATS; i++) {
+ *buf = VIRTNET_STAT(&sample, i);
+ VIRTNET_STAT(&total, i) += VIRTNET_STAT(stats, i);
+ buf++;
+ }
+ }
+
+ for (i = 0; i < VIRTNET_NUM_STATS; i++) {
+ *buf = VIRTNET_STAT(&total, i);
+ buf++;
+ }
+}
+
static const struct ethtool_ops virtnet_ethtool_ops = {
.get_drvinfo = virtnet_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_ringparam = virtnet_get_ringparam,
+ .get_ethtool_stats = virtnet_get_ethtool_stats,
+ .get_strings = virtnet_get_strings,
+ .get_sset_count = virtnet_get_sset_count,
};
#define MIN_MTU 68
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