virtio_net: fix oom handling on tx

virtio net will never try to overflow the TX ring, so the only reason
add_buf may fail is out of memory. Thus, we can not stop the
device until some request completes - there's no guarantee anything
at all is outstanding.

Make the error message clearer as well: error here does not
indicate queue full.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (...and avoid TX_BUSY)
Cc: stable@kernel.org  # .34.x (s/virtqueue_/vi->svq->vq_ops->/)
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rusty Russell 2010-07-02 16:34:01 +00:00 коммит произвёл David S. Miller
Родитель 1788f49548
Коммит 58eba97d07
1 изменённых файлов: 13 добавлений и 8 удалений

Просмотреть файл

@ -562,7 +562,6 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
struct virtnet_info *vi = netdev_priv(dev);
int capacity;
again:
/* Free up any pending old buffers before queueing new ones. */
free_old_xmit_skbs(vi);
@ -571,14 +570,20 @@ again:
/* This can happen with OOM and indirect buffers. */
if (unlikely(capacity < 0)) {
netif_stop_queue(dev);
dev_warn(&dev->dev, "Unexpected full queue\n");
if (unlikely(!virtqueue_enable_cb(vi->svq))) {
virtqueue_disable_cb(vi->svq);
netif_start_queue(dev);
goto again;
if (net_ratelimit()) {
if (likely(capacity == -ENOMEM)) {
dev_warn(&dev->dev,
"TX queue failure: out of memory\n");
} else {
dev->stats.tx_fifo_errors++;
dev_warn(&dev->dev,
"Unexpected TX queue failure: %d\n",
capacity);
}
}
return NETDEV_TX_BUSY;
dev->stats.tx_dropped++;
kfree_skb(skb);
return NETDEV_TX_OK;
}
virtqueue_kick(vi->svq);