[PATCH RFC v3 2/3] virtio_net: bql
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2014-10-20 06:49:35
Also in:
lkml, netdev
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Improve tx batching using byte queue limits. Should be especially effective for MQ. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/net/virtio_net.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 14f4cda..b83d39d 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -227,6 +227,7 @@ static unsigned int free_old_xmit_skbs(struct netdev_queue *txq, 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; while (packets < budget && (skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
@@ -234,6 +235,7 @@ static unsigned int free_old_xmit_skbs(struct netdev_queue *txq, u64_stats_update_begin(&stats->tx_syncp); stats->tx_bytes += skb->len; + bytes += skb->len; stats->tx_packets++; u64_stats_update_end(&stats->tx_syncp);
@@ -241,6 +243,8 @@ static unsigned int free_old_xmit_skbs(struct netdev_queue *txq, packets++; } + netdev_tx_completed_queue(txq, packets, bytes); + if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) netif_tx_start_queue(txq);
@@ -959,6 +963,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) int err; struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); bool kick = !skb->xmit_more; + unsigned int bytes = skb->len; virtqueue_disable_cb(sq->vq);
@@ -976,6 +981,8 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) return NETDEV_TX_OK; } + netdev_tx_sent_queue(txq, bytes); + /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (sq->vq->num_free < 2+MAX_SKB_FRAGS)
--
MST