From d7dfc5cf56b0e34f52d70260b024335e98f4c8c9 Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Wed, 17 Jan 2018 15:38:25 +0900 Subject: [PATCH] virtio_net: Add ethtool stats The main purpose of this patch is adding a way of checking per-queue stats. It's useful to debug performance problems on multiqueue environment. $ ethtool -S ens10 NIC statistics: rx_queue_0_packets: 2090408 rx_queue_0_bytes: 3164825094 rx_queue_1_packets: 2082531 rx_queue_1_bytes: 3152932314 tx_queue_0_packets: 2770841 tx_queue_0_bytes: 4194955474 tx_queue_1_packets: 3084697 tx_queue_1_bytes: 4670196372 This change converts existing per-cpu stats structure into per-queue one. This should not impact on performance since each queue counter is not updated concurrently by multiple cpus. Performance numbers: - Guest has 2 vcpus and 2 queues - Guest runs netserver - Host runs 100-flow super_netperf Before After Diff UDP_STREAM 18byte 86.22 87.00 +0.90% UDP_STREAM 1472byte 4055.27 4042.18 -0.32% TCP_STREAM 16956.32 16890.63 -0.39% UDP_RR 178667.11 185862.70 +4.03% TCP_RR 128473.04 124985.81 -2.71% Signed-off-by: Toshiaki Makita Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 191 +++++++++++++++++++++++++++++---------- 1 file changed, 141 insertions(+), 50 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 12dfc5fee58e..626c27352ae2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -66,16 +66,39 @@ static const unsigned long guest_offloads[] = { VIRTIO_NET_F_GUEST_UFO }; -struct virtnet_stats { - struct u64_stats_sync tx_syncp; - struct u64_stats_sync rx_syncp; - u64 tx_bytes; - u64 tx_packets; - - u64 rx_bytes; - u64 rx_packets; +struct virtnet_stat_desc { + char desc[ETH_GSTRING_LEN]; + size_t offset; }; +struct virtnet_sq_stats { + struct u64_stats_sync syncp; + u64 packets; + u64 bytes; +}; + +struct virtnet_rq_stats { + struct u64_stats_sync syncp; + u64 packets; + u64 bytes; +}; + +#define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m) +#define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m) + +static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = { + { "packets", VIRTNET_SQ_STAT(packets) }, + { "bytes", VIRTNET_SQ_STAT(bytes) }, +}; + +static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = { + { "packets", VIRTNET_RQ_STAT(packets) }, + { "bytes", VIRTNET_RQ_STAT(bytes) }, +}; + +#define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc) +#define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc) + /* Internal representation of a send virtqueue */ struct send_queue { /* Virtqueue associated with this send _queue */ @@ -87,6 +110,8 @@ struct send_queue { /* Name of the send queue: output.$index */ char name[40]; + struct virtnet_sq_stats stats; + struct napi_struct napi; }; @@ -99,6 +124,8 @@ struct receive_queue { struct bpf_prog __rcu *xdp_prog; + struct virtnet_rq_stats stats; + /* Chain pages by the private ptr. */ struct page *pages; @@ -152,9 +179,6 @@ struct virtnet_info { /* Packet virtio header size */ u8 hdr_len; - /* Active statistics */ - struct virtnet_stats __percpu *stats; - /* Work struct for refilling if we run low on memory. */ struct delayed_work refill; @@ -1127,7 +1151,6 @@ static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit) struct virtnet_info *vi = rq->vq->vdev->priv; unsigned int len, received = 0, bytes = 0; void *buf; - struct virtnet_stats *stats = this_cpu_ptr(vi->stats); if (!vi->big_packets || vi->mergeable_rx_bufs) { void *ctx; @@ -1150,10 +1173,10 @@ static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit) schedule_delayed_work(&vi->refill, 0); } - u64_stats_update_begin(&stats->rx_syncp); - stats->rx_bytes += bytes; - stats->rx_packets += received; - u64_stats_update_end(&stats->rx_syncp); + u64_stats_update_begin(&rq->stats.syncp); + rq->stats.bytes += bytes; + rq->stats.packets += received; + u64_stats_update_end(&rq->stats.syncp); return received; } @@ -1162,8 +1185,6 @@ static void free_old_xmit_skbs(struct send_queue *sq) { struct sk_buff *skb; unsigned int len; - struct virtnet_info *vi = sq->vq->vdev->priv; - struct virtnet_stats *stats = this_cpu_ptr(vi->stats); unsigned int packets = 0; unsigned int bytes = 0; @@ -1182,10 +1203,10 @@ static void free_old_xmit_skbs(struct send_queue *sq) if (!packets) return; - u64_stats_update_begin(&stats->tx_syncp); - stats->tx_bytes += bytes; - stats->tx_packets += packets; - u64_stats_update_end(&stats->tx_syncp); + u64_stats_update_begin(&sq->stats.syncp); + sq->stats.bytes += bytes; + sq->stats.packets += packets; + u64_stats_update_end(&sq->stats.syncp); } static void virtnet_poll_cleantx(struct receive_queue *rq) @@ -1474,24 +1495,25 @@ static void virtnet_stats(struct net_device *dev, struct rtnl_link_stats64 *tot) { struct virtnet_info *vi = netdev_priv(dev); - int cpu; unsigned int start; + int i; - for_each_possible_cpu(cpu) { - struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); + for (i = 0; i < vi->max_queue_pairs; i++) { u64 tpackets, tbytes, rpackets, rbytes; + struct receive_queue *rq = &vi->rq[i]; + struct send_queue *sq = &vi->sq[i]; do { - start = u64_stats_fetch_begin_irq(&stats->tx_syncp); - tpackets = stats->tx_packets; - tbytes = stats->tx_bytes; - } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start)); + start = u64_stats_fetch_begin_irq(&sq->stats.syncp); + tpackets = sq->stats.packets; + tbytes = sq->stats.bytes; + } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start)); do { - start = u64_stats_fetch_begin_irq(&stats->rx_syncp); - rpackets = stats->rx_packets; - rbytes = stats->rx_bytes; - } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start)); + start = u64_stats_fetch_begin_irq(&rq->stats.syncp); + rpackets = rq->stats.packets; + rbytes = rq->stats.bytes; + } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start)); tot->rx_packets += rpackets; tot->tx_packets += tpackets; @@ -1829,6 +1851,83 @@ static int virtnet_set_channels(struct net_device *dev, return err; } +static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data) +{ + struct virtnet_info *vi = netdev_priv(dev); + char *p = (char *)data; + unsigned int i, j; + + switch (stringset) { + case ETH_SS_STATS: + for (i = 0; i < vi->curr_queue_pairs; i++) { + for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) { + snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s", + i, virtnet_rq_stats_desc[j].desc); + p += ETH_GSTRING_LEN; + } + } + + for (i = 0; i < vi->curr_queue_pairs; i++) { + for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) { + snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s", + i, virtnet_sq_stats_desc[j].desc); + p += ETH_GSTRING_LEN; + } + } + break; + } +} + +static int virtnet_get_sset_count(struct net_device *dev, int sset) +{ + struct virtnet_info *vi = netdev_priv(dev); + + switch (sset) { + case ETH_SS_STATS: + return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN + + VIRTNET_SQ_STATS_LEN); + default: + return -EOPNOTSUPP; + } +} + +static void virtnet_get_ethtool_stats(struct net_device *dev, + struct ethtool_stats *stats, u64 *data) +{ + struct virtnet_info *vi = netdev_priv(dev); + unsigned int idx = 0, start, i, j; + const u8 *stats_base; + size_t offset; + + for (i = 0; i < vi->curr_queue_pairs; i++) { + struct receive_queue *rq = &vi->rq[i]; + + stats_base = (u8 *)&rq->stats; + do { + start = u64_stats_fetch_begin_irq(&rq->stats.syncp); + for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) { + offset = virtnet_rq_stats_desc[j].offset; + data[idx + j] = *(u64 *)(stats_base + offset); + } + } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start)); + idx += VIRTNET_RQ_STATS_LEN; + } + + for (i = 0; i < vi->curr_queue_pairs; i++) { + struct send_queue *sq = &vi->sq[i]; + + stats_base = (u8 *)&sq->stats; + do { + start = u64_stats_fetch_begin_irq(&sq->stats.syncp); + for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) { + offset = virtnet_sq_stats_desc[j].offset; + data[idx + j] = *(u64 *)(stats_base + offset); + } + } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start)); + idx += VIRTNET_SQ_STATS_LEN; + } +} + static void virtnet_get_channels(struct net_device *dev, struct ethtool_channels *channels) { @@ -1928,6 +2027,9 @@ 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_strings = virtnet_get_strings, + .get_sset_count = virtnet_get_sset_count, + .get_ethtool_stats = virtnet_get_ethtool_stats, .set_channels = virtnet_set_channels, .get_channels = virtnet_get_channels, .get_ts_info = ethtool_op_get_ts_info, @@ -2420,6 +2522,9 @@ static int virtnet_alloc_queues(struct virtnet_info *vi) sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len); sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); + + u64_stats_init(&vi->rq[i].stats.syncp); + u64_stats_init(&vi->sq[i].stats.syncp); } return 0; @@ -2544,7 +2649,7 @@ static int virtnet_validate(struct virtio_device *vdev) static int virtnet_probe(struct virtio_device *vdev) { - int i, err; + int i, err = -ENOMEM; struct net_device *dev; struct virtnet_info *vi; u16 max_queue_pairs; @@ -2621,17 +2726,6 @@ static int virtnet_probe(struct virtio_device *vdev) vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; - vi->stats = alloc_percpu(struct virtnet_stats); - err = -ENOMEM; - if (vi->stats == NULL) - goto free; - - for_each_possible_cpu(i) { - struct virtnet_stats *virtnet_stats; - virtnet_stats = per_cpu_ptr(vi->stats, i); - u64_stats_init(&virtnet_stats->tx_syncp); - u64_stats_init(&virtnet_stats->rx_syncp); - } INIT_WORK(&vi->config_work, virtnet_config_changed_work); @@ -2668,7 +2762,7 @@ static int virtnet_probe(struct virtio_device *vdev) */ dev_err(&vdev->dev, "device MTU appears to have changed " "it is now %d < %d", mtu, dev->min_mtu); - goto free_stats; + goto free; } dev->mtu = mtu; @@ -2692,7 +2786,7 @@ static int virtnet_probe(struct virtio_device *vdev) /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ err = init_vqs(vi); if (err) - goto free_stats; + goto free; #ifdef CONFIG_SYSFS if (vi->mergeable_rx_bufs) @@ -2747,8 +2841,6 @@ free_vqs: cancel_delayed_work_sync(&vi->refill); free_receive_page_frags(vi); virtnet_del_vqs(vi); -free_stats: - free_percpu(vi->stats); free: free_netdev(dev); return err; @@ -2781,7 +2873,6 @@ static void virtnet_remove(struct virtio_device *vdev) remove_vq_common(vi); - free_percpu(vi->stats); free_netdev(vi->dev); } -- 2.30.2