Improve tx batching using byte queue limits.
Should be especially effective for MQ.
Signed-off-by: Michael S. Tsirkin <mst at 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
