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authorToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>2018-07-23 23:36:06 +0900
committerDavid S. Miller <davem@davemloft.net>2018-07-25 12:53:37 -0700
commit2c4a2f7d826329966e8ab86f842a95d3234c64da (patch)
tree73371e30771a5f615cd9cd8744f937b83894beaf /drivers/net/virtio_net.c
parenta0929a44c2065da33c17b1b8015a88401d71ca7b (diff)
downloadlinux-2c4a2f7d826329966e8ab86f842a95d3234c64da.tar.bz2
virtio_net: Make drop counter per-queue
Since when XDP was introduced, drop counter has been able to be updated much more frequently than before, as XDP_DROP increments the counter. Thus for performance analysis per-queue drop counter would be useful. Also this avoids cache contention and race on updating the counter. It is currently racy because napi handlers read-modify-write it without any locks. There are more counters in dev->stats that are racy, but I left them per-device, because they are rarely updated and does not worth being per-queue counters IMHO. To fix them we need atomic ops or some kind of locks. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d03bfc4fce8e..7a47ce750a43 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -87,6 +87,7 @@ struct virtnet_sq_stats {
struct virtnet_rq_stat_items {
u64 packets;
u64 bytes;
+ u64 drops;
};
struct virtnet_rq_stats {
@@ -109,6 +110,7 @@ static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
{ "packets", VIRTNET_RQ_STAT(packets) },
{ "bytes", VIRTNET_RQ_STAT(bytes) },
+ { "drops", VIRTNET_RQ_STAT(drops) },
};
#define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc)
@@ -705,7 +707,7 @@ err:
err_xdp:
rcu_read_unlock();
- dev->stats.rx_dropped++;
+ stats->rx.drops++;
put_page(page);
xdp_xmit:
return NULL;
@@ -728,7 +730,7 @@ static struct sk_buff *receive_big(struct net_device *dev,
return skb;
err:
- dev->stats.rx_dropped++;
+ stats->rx.drops++;
give_pages(rq, page);
return NULL;
}
@@ -952,7 +954,7 @@ err_skb:
put_page(page);
}
err_buf:
- dev->stats.rx_dropped++;
+ stats->rx.drops++;
dev_kfree_skb(head_skb);
xdp_xmit:
return NULL;
@@ -1632,7 +1634,7 @@ static void virtnet_stats(struct net_device *dev,
int i;
for (i = 0; i < vi->max_queue_pairs; i++) {
- u64 tpackets, tbytes, rpackets, rbytes;
+ u64 tpackets, tbytes, rpackets, rbytes, rdrops;
struct receive_queue *rq = &vi->rq[i];
struct send_queue *sq = &vi->sq[i];
@@ -1646,17 +1648,18 @@ static void virtnet_stats(struct net_device *dev,
start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
rpackets = rq->stats.items.packets;
rbytes = rq->stats.items.bytes;
+ rdrops = rq->stats.items.drops;
} while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
tot->rx_packets += rpackets;
tot->tx_packets += tpackets;
tot->rx_bytes += rbytes;
tot->tx_bytes += tbytes;
+ tot->rx_dropped += rdrops;
}
tot->tx_dropped = dev->stats.tx_dropped;
tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
- 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;
}